Ethnobotany of Local Vegetables and Spices in Sakon Nakhon Province, Thailand

Abstract

Local vegetables and spices are essential components of traditional food and health systems in northeastern Thailand, yet quantitative ethnobotanical evidence remains limited. This study documents the diversity, utilization, and cultural significance of vegetables and spices used in Sang Kho Sub-district, Phu Phan District, Sakon Nakhon Province. Ethnobotanical data were collected in 2025 through field surveys, voucher-based plant identification, semi-structured interviews, and participant observation involving 92 informants across 23 villages. Cultural significance and medicinal knowledge were evaluated using the Cultural Importance Index (CI), Informant Consensus Factor (FIC), and Fidelity Level (FL). A total of 113 taxa belonging to 94 genera and 49 plant families were recorded. Poaceae and Zingiberaceae were the most species-rich families. Native species slightly predominated (51.33%), and herbaceous taxa were most common. Leaves were the most frequently used plant part. Most taxa were used as vegetables (92 species), followed by traditional medicines (20 species), spices or seasonings (18 species), and food ingredients or culinary additives (18 species). The highest CI values were recorded for Allium ascalonicum L. (1.152), Capsicum annuum L. (1.098), and Coriandrum sativum L. (1.043). FIC values ranged from 0.60 to 1.00, with complete consensus for circulatory and neurological disorders. Cymbopogon citratus showed the highest FL (75%) for gastrointestinal uses. These findings demonstrate the close integration of food and medicine in local plant-use systems and provide baseline data for food system resilience and cultural knowledge conservation.

1. Introduction

Local vegetables and traditional spices play a critical role in food security, nutrition, and cultural identity across many regions of the world, particularly in communities where traditional ecological knowledge continues to guide food practices [1]. In Southeast Asia, rural households rely on a rich diversity of wild, semi-domesticated, and cultivated vegetables alongside aromatic herbs and spices that enhance flavor, support health, and reinforce culinary heritage [2]. Beyond their nutritional value, these plants contain bioactive compounds with medicinal properties and serve as cultural markers embedded in local cuisines, ritual practices, and daily food preparation. Together, vegetables and spices form an integrated traditional food system that has supported community resilience over generations. However, the continued transmission of this knowledge system is increasingly threatened by the rapid modernization of food environments [3].

In Thailand—particularly in the northeastern Isan region—modernization has brought profound changes to dietary habits. The expansion of commercial agriculture, increased market integration, and the influence of globalized food culture have contributed to a decline in the everyday use of traditional vegetables and local spices. Supermarkets and urban-style convenience stores now provide standardized commercial produce and packaged spice products, many of which are imported from abroad [4,5]. Consequently, younger generations are shifting toward purchased, packaged, or imported alternatives rather than relying on locally available wild plants, homegrown aromatics, and traditional seasoning species. This trend not only reduces the consumption of indigenous edible plants but also accelerates the erosion of culinary knowledge, local flavor identities, and plant-based cultural heritage [6]. Despite these changes, local vegetables and spices remain ecologically abundant and culturally significant in many rural communities, although their use is increasingly uneven and vulnerable to knowledge loss [7].

Although several ethnobotanical studies in northeastern Thailand have documented edible plant resources, existing knowledge remains fragmented, largely descriptive, and geographically restricted. While some studies mention the use of spices, such information is often scattered, secondary, or embedded within broader categories of edible plants without dedicated analysis. As a result, the roles of local vegetables and traditional spices—whether as components of culinary identity, daily subsistence, or household health practices—have not been systematically emphasized or clearly organized in the literature [8]. Existing research rarely provides a focused examination of local vegetables and traditional spices, and discussions of these plants are often embedded within broader categories of edible or useful species without dedicated analysis [9]. Consequently, important questions remain regarding the diversity, cultural functions, and patterns of use of local vegetables and spices in rural communities. Addressing these gaps is essential for establishing a clear understanding of their ethnobotanical significance and for supporting the documentation and preservation of plant-based cultural heritage in northeastern Thailand [10].

Sang Kho Sub-district in Phu Phan District, Sakon Nakhon Province, lies within the culturally rich and biodiverse Phu Phan mountain range. The area encompasses community forests, agricultural fields, and wetland habitats that provide a wide array of edible plants—including leafy vegetables, edible shoots, seasoning herbs, and aromatic spices—traditionally harvested for both food and medicinal purposes [11]. Yet, despite their ecological availability, the extent to which local vegetables and spices are still valued and used under modern dietary transitions remains poorly understood. No previous ethnobotanical study has focused on this sub-district, leaving significant gaps in understanding how modernization may be reshaping traditional plant knowledge, cooking practices, and local flavor systems.

Therefore, this study aims to provide a systematic ethnobotanical assessment of local vegetables and spices used in Sang Kho Sub-district, northeastern Thailand. Specifically, the objectives are as follows:

(i)

Document and taxonomically verify the diversity of wild, semi-domesticated, and cultivated vegetable and spice species used by local communities through field surveys, voucher specimen collection, and herbarium-based identification;

(ii)

Record and classify patterns of utilization—including vegetables, spices/seasonings, condiments, food ingredients, and traditional medicinal uses—based on ethnobotanical interviews and participant observation;

(iii)

Quantitatively evaluate the cultural significance and knowledge consensus associated with these species using the Cultural Importance Index (CI), Informant Consensus Factor (FIC), and Fidelity Level (FL);

(iv)

Examine sociocultural dimensions of traditional food knowledge, including perceived availability, multifunctional uses, and continuity of plant-based food practices within the contemporary local context.

By integrating botanical documentation, qualitative ethnographic data, and quantitative ethnobotanical indices, this research provides an empirical foundation for understanding local food and seasoning systems in Sang Kho Sub-district. The findings contribute to broader discussions on cultural knowledge maintenance, biodiversity-based food systems, and community-level resource management in northeastern Thailand.

2. Materials and Methods

2.1. Study Area

Sang Kho Sub-district is situated in Phu Phan District, Sakon Nakhon Province, in northeastern Thailand (Figure 1). The area occupies part of the Phu Phan mountain range, a landscape characterized by gently undulating uplands, dry evergreen forests, mixed deciduous forests, and seasonally inundated wetlands that together support high floristic diversity. The local environment is shaped by a tropical savanna climate (Aw), which features pronounced seasonal variation. According to long-term climatic patterns for the Phu Phan region, temperatures generally range from 15 to 34 °C, with cooler nighttime temperatures occurring between November and January. The climate comprises a hot season from mid-March to early May, a rainy season extending from May to October, and a cool–dry season from late November to February. Rainfall is highly seasonal, with peak precipitation occurring in August, while the driest period typically spans November to February, coinciding with the region’s “rainless interval.” These seasonal shifts strongly influence vegetation dynamics and the availability of wild edible plants [12].

Land use in Sang Kho includes community forests, rice fields, fallow areas, home gardens, and mixed-agricultural mosaics. These habitats supply a broad spectrum of wild and cultivated vegetables, herbs, and spices that are integral to local subsistence and culinary traditions. The population is predominantly Isan, with livelihoods centered on rice farming, livestock husbandry, and small-scale gathering of forest products. Traditional ecological knowledge remains closely linked to the seasonal rhythms of the landscape, shaping patterns of plant harvesting, food preparation, and household health practices. This ecological and cultural context makes Sang Kho Sub-district an ideal setting for examining the diversity, cultural importance, and traditional knowledge associated with local vegetables.

2.2. Field Survey and Data Collection

Field surveys were conducted in Sang Kho Sub-district, which comprises 23 villages, to document the diversity of local vegetables and traditional spices used by the community. Field surveys were undertaken in 2025 using direct plant exploration across community forests, home gardens, agricultural fields, fallow lands, and local markets. The primary objective was to record locally available edible plants, their culinary and seasoning roles, and their distribution.

During each survey, edible plants—including wild, semi-domesticated, and cultivated vegetables and spices—were observed, photographed, and collected as voucher specimens. Standard botanical collecting procedures were followed, with notes taken on habitat, growth form, vernacular names, used parts, and traditional applications. Fresh specimens were pressed, dried, and mounted for long-term preservation.

Plant identification was performed using regional floras, taxonomic keys, and comparison with authenticated herbarium collections at the Vascular Plant Herbarium, Mahasarakham University (VMSU), Kantharawichai District, Maha Sarakham Province. When necessary, scientific names were verified using reputable online taxonomic databases such as Plants of the World Online (POWO) (https://powo.science.kew.org) (accessed on 20 August 2025) [14] and World Flora Online (WFO) (https://www.worldfloraonline.org/) (accessed on 20 August 2025) [15]. Conservation status was assigned based on the IUCN Red List. Species not yet assessed were categorized as Not Evaluated (NE).

All plant collections and field observations were conducted with permission from local authorities and with respect for community guidelines regarding the use of forest and agricultural resources.

2.3. Ethnobotany Study

The ethnobotanical component aimed to document traditional knowledge and practices related to local vegetables and spices in Sang Kho Sub-district. Data were collected in 2025 through semi-structured interviews, informal conversations, and participant observation. A total of 92 informants participated in the study (46 male, 46 female), aged 25–70 years (

Table 1. Demographic, linguistic, and cultural characteristics of the surveyed villages, including GPS coordinates, gender (M = male, F = female), ethnicity, spoken languages, and religion.

Villages	GPS Coordinates		Gender		Ethnicity	Language	Religion
	Latitude (N, S)	Longitude (E, W)	M	F
Ban Chat San	16°52′32″ N	103°56′15″ E	2	2	Lao Isan	Isan	Buddhism
Ban Chiang Saen Phatthana	16°51′45.9″ N	103°55′45.6″ E	2	2	Lao Isan	Isan, Thai	Buddhism; Islam
Ban Chom Phu Phan	16°52′46″ N	103°56′19″ E	2	2	Lao Isan	Isan, Thai	Buddhism
Ban Chom Phu Phan Klang	16°52′56″ N	103°56′20″ E	2	2	Lao Isan	Isan, Thai	Buddhism
Ban Chom Phu Phan Nuea	16°53′7″ N	103°56′20″ E	2	2	Lao Isan	Isan, Thai	Buddhism
Ban Don Khaen	16°53′29″ N	103°55′27″ E	2	2	Lao Isan	Isan	Buddhism
Ban Mai Phatthana	16°53′52″ N	103°55′03″ E	2	2	Lao Isan	Isan	Buddhism
Ban Na Kham Klang	16°57′41.1″ N	103°54′57.0″ E	2	2	Lao Isan	Isan	Buddhism
Ban Na Yo	16°51′30″ N	103°55′51″ E	2	2	Lao Isan	Isan	Buddhism
Ban Non Hua Chang	16°51′6″ N	103°56′8″ E	2	2	Lao Isan	Isan	Buddhism
Ban Non Samran	16°55′31.3″ N	103°55′39.4″ E	2	2	Lao Isan	Isan, Thai	Buddhism; Christianity
Ban Non Suan Pa	16°51′37.3″ N	103°56′18.9″ E	2	2	Lao Isan	Isan, Thai	Buddhism
Ban Pho Chai Phatthana	16°51′21.5″ N	103°56′17.6″ E	2	2	Lao Isan	Isan	Buddhism
Ban Phu Phan Thong	16°55′45.0″ N	103°54′33.3″ E	2	2	Lao Isan	Isan	Buddhism; Islam
Ban Sai Thong	16°56′57.4″ N	103°54′46.0″ E	2	2	Lao Isan	Isan, Thai	Buddhism; Christianity
Ban Sang Kaeo	16°49′37″ N	103°57′46″ E	2	2	Lao Isan	Isan	Buddhism; Islam
Ban Sang Kho (Moo 1)	16°51′20.4″ N	103°56′06.6″ E	2	2	Lao Isan	Isan	Buddhism
Ban Sang Kho (Moo 2)	16°51′34.8″ N	103°55′53.2″ E	2	2	Lao Isan	Isan	Buddhism
Ban Sang Kho (Moo 12)	16°51′41″ N	103°55′59″ E	2	2	Lao Isan	Isan	Buddhism
Ban Saphan Sam	16°54′24.4″ N	103°55′26.0″ E	2	2	Lao Isan	Isan	Buddhism
Ban Tham Si Kaeo	16°55′14.3″ N	103°54′12.3″ E	2	2	Lao Isan	Isan, Thai	Buddhism; Christianity
Ban Ton	16°56′33.1″ N	103°54′28.8″ E	2	2	Lao Isan	Isan, Thai	Buddhism; Christianity
Ban Udom Sap	16°56′20.6″ N	103°55′08.7″ E	2	2	Lao Isan	Isan	Buddhism

).

Informant selection combined purposive [16] and snowball sampling [17] to ensure representation of individuals with direct knowledge of edible and seasoning plants. Inclusion criteria prioritized persons who had demonstrable experience or responsibilities in food preparation, plant gathering, cultivation, or market trade—specifically elders, home cooks, smallholder farmers, foragers, market vendors, and other community members recognized for their knowledge of local vegetables and spices. Initial key informants were identified through village leaders and local agricultural extension officers; subsequent participants were recruited by referral (snowballing) from these initial contacts to capture a breadth of experiential knowledge across the 23 villages.

Interviews followed a semi-structured format and covered vernacular names, used parts, harvesting season, preparation and preservation methods, culinary roles (e.g., vegetable, condiment, spice), associated traditional remedies, and perceived availability. Demonstrations of harvesting, processing, and cooking were requested when informants were willing to provide them. Participant observation in home gardens, kitchens, markets, and forest gathering sites was used to contextualize interview data and to verify reported uses through direct observation.

Prior to data collection, the study’s aims and procedures were thoroughly communicated to all participants, and informed consent was obtained in accordance with the International Society of Ethnobiology (ISE) Code of Ethics [18] and the Nagoya Protocol on Access and Benefit-Sharing [19]. Participants were made aware of their rights, including voluntary involvement and the option to withdraw at any point without any negative repercussions.

Although this research did not collect personal or sensitive data and therefore did not require formal institutional ethical approval, all activities adhered strictly to international ethical guidelines for ethnobotanical research, ensuring respect, openness, and reciprocal benefit for the participating communities.

2.4. Utilization Categories

All recorded plant species were classified into utilization categories based on their primary and secondary roles within the community’s food and seasoning systems. Categorization followed standard ethnobotanical frameworks [20,21], with adjustments made to reflect local culinary practices in northeastern Thailand. Each species was assigned to one or more of the following categories:

• Vegetable: Plants consumed as leafy greens, shoots, stems, flowers, fruits, tubers, or other edible parts commonly used as staple or supplementary vegetables.
• Spice/seasoning: Aromatic plants used to enhance flavor, aroma, or color in traditional dishes, including herbs, pungent spices, and other seasoning agents.
• Condiment: Plant materials processed into dips, pastes, or fermented products (e.g., chili pastes, herbal condiments) consumed alongside meals.
• Food ingredient/culinary additive: Species used as minor ingredients to provide thickening, souring, coloring, or textural enhancement (e.g., sour fruits, mucilaginous plants).
• Traditional medicine: Plants incorporated into home remedies, restorative soups, postpartum foods, or preventive dietary practices according to local knowledge.

Classification was based on information obtained from informant interviews, direct observation of plant use during cooking, and cross-checking with knowledgeable community members, following standard ethnobotanical documentation protocols [22,23]. When a species fulfilled multiple roles (e.g., vegetable and spice), all relevant categories were recorded to represent its multifunctional cultural importance accurately.

2.5. Data Analysis

2.5.1. Cultural Importance Index (CI)

The Cultural Importance Index (CI) was applied to evaluate the cultural significance of local vegetables and spices used by communities in Sang Kho Sub-district. This index employs quantitative ethnobotanical methods to assess both the frequency and diversity of plant uses by categorizing utilization reports according to different use types. Such an approach allows for a more detailed understanding of multifunctional plant species within local food systems, in contrast to indices that reflect only overall use frequency.

Data were obtained from local informants, and each plant species was analyzed based on the number of utilization reports recorded across distinct use categories. For CI calculation, all use reports were first classified by type of utilization, and the frequency of each report was documented. The CI was then calculated using the following equation [24]:

$$\mathrm{CI} = \sum _{\mathrm{u} ={ \mathrm{u}}_1}^{{\mathrm{u}}_{\mathrm{NC}}}\sum _{\mathrm{i} = {\mathrm{i}}_1}^{{\mathrm{i}}_{\mathrm{NC}}}{\displaystyle \frac{\mathrm{U}{\mathrm{R}}_{\mathrm{ui}}}{\mathrm{N}}}$$

(1)

where CI represents the cultural importance index of a given plant species, UR_ui denotes the number of utilization reports for use category u cited by informant i, I is the total number of utilization categories, NC refers to the total number of distinct utilizations, and N is the total number of informants. The resulting CI values reflect both the frequency and versatility of plant use, thereby highlighting species that hold high cultural relevance and play essential roles in local dietary practices, culinary traditions, and everyday livelihoods.

2.5.2. Informant Consensus Factor (FIC)

The Informant Consensus Factor (FIC) was used to evaluate the level of agreement among informants regarding the use of medicinal plants for specific health categories in Sang Kho Sub-district. This index helps identify ailments for which plant-based remedies are widely shared and consistently recognized within the community, thereby reflecting the homogeneity of traditional medicinal knowledge. The FIC was calculated using the formula [25]:

$$\mathrm{FIC} = {\displaystyle \frac{{\mathrm{N}}_{\mathrm{ur}}-{\mathrm{N}}_{\mathrm{t}}}{{\mathrm{N}}_{\mathrm{ur}}-1}}$$

(2)

where N_ur represents the total number of use reports for all plant species within a particular medicinal category, and N_t is the number of species cited for that category. FIC values range from 0 to 1, with higher values indicating stronger consensus among informants and a more focused body of shared knowledge regarding plant use for specific health conditions.

2.5.3. Fidelity Level (FL)

The Fidelity Level (FL) was calculated to determine the degree of specificity with which a plant species is associated with a particular medicinal use. This index measures the proportion of informants who cited a species for the same ailment relative to all medicinal uses reported for that species, thereby reflecting the consistency and cultural reliability of its traditional application. The FL was calculated using the following equation [26]:

$$\mathrm{FL} = {\displaystyle \frac{{\mathrm{I}}_{\mathrm{p}}}{{\mathrm{I}}_{\mathrm{u}}}} \times 100$$

(3)

where I_p is the number of informants who reported the use of a plant species for a specific health condition, and I_u is the total number of informants who mentioned the species for any medicinal purpose. Higher FL values indicate stronger agreement among informants and highlight plant species with well-established and culturally significant medicinal roles within the community.

3. Results

3.1. Diversity of Local Vegetables and Spices

A total of 113 taxa, representing 94 genera and 49 plant families, were recorded as local vegetables and spices in Sang Kho Sub-district, Phu Phan District, Sakon Nakhon Province (

Table 2. List of local vegetables and spices in Sang Kho Sub-district, Phu Phan District, Sakon Nakhon Province, Thailand, including Family name, scientific names, vernacular names, distribution status in Thailand (DiT), growth habit (GH), resource, used parts, utilization categories, modes of consumption, conservation status (proposed by authors with IUCN Red Lists) (CS), and voucher specimen numbers.

Family	Name	Vernacular Name	DiT	GH	Resource	Used Parts	Utilization	Mode of Consumption	CI	CS	Voucher No.
Alismataceae	Limnocharis flava (L.) Buchenau	Phak khan chong	Introduced	Hb	B	If	Vg	Boiled or eaten fresh as a vegetable with chili paste.	0.565	NE	TJ-SK0052
Amaranthaceae	Amaranthus blitum L.	Phak khom hat	Introduced	Hb	W	Lf, St	Vg	Boiled and eaten as a vegetable with chili paste.	0.228	NE	TJ-SK0081
	Amaranthus viridis L.	Phak khom	Introduced	Hb	W	Lf, St	Vg	Boiled and eaten as a vegetable with chili paste.	0.239	NE	TJ-SK0083
Amaryllidaceae	Allium ascalonicum L.	Hom daeng	Introduced	Hb	C	Bu	Cd	Used as an ingredient in traditional dipping sauces, including chili–fish sauce (Nam Pla Prik).	1.152	NE	TJ-SK0103
						Bu	Sp	Used as a spice to enhance aroma in stir-fried dishes.
						Bu	Tm	Used as medicine.
						Bu, Lf	Vg	Bulb: Eaten fresh as a vegetable with chili paste; Leaf: Eaten fresh or used in boiled, stir-fried, and curry dishes.
	Allium sativum L.	Krathiam	Introduced	Hb	C	Bu	Cd	Used as an ingredient in dipping sauces.	0.620	NE	TJ-SK0107
						Bu	Sp	Used as a spice to enhance aroma in stir-fried dishes.
						Bu	Tm	Used as medicine.
						Bu, Lf	Vg	Eaten fresh as a vegetable with chili paste.
	Allium tuberosum Rottl. ex Spreng.	Phak paen	Introduced	Hb	C	Lf	Vg	Boiled or eaten fresh as a vegetable with chili paste or used to make pickled vegetables.	0.467	NE	TJ-SK0012
Anacardiaceae	Spondias mombin L.	Bak kok	Introduced	Tr	B	Ft	Fc	Used as a seasoning to add sourness.	0.522	LC	TJ-SK0037
Annonaceae	Annona squamosa L.	Noi na	Introduced	Tr	C	Lf	Vg	Used as an ingredient in Isan-style “Gaeng Om” (herbal curry).	0.054	LC	TJ-SK0110
Apiaceae	Anethum graveolens L.	Phak chi lao	Introduced	Hb	C	Lf	Vg	Eaten fresh with chili paste or used in Isan-style “Gaeng Om.”	0.685	NE	TJ-SK0059
	Apium graveolens L.	Phak khuen chai	Introduced	Hb	C	Lf	Vg	Eaten fresh with chili paste or used in boiled, stir-fried dishes, or Isan-style “Gaeng Om”.	0.598	LC	TJ-SK0035
	Centella asiatica (L.) Urb.	Phak nok	Native	Hb	C	Lf	Vg	Eaten fresh with chili paste.	0.337	LC	TJ-SK0049
	Coriandrum sativum L.	Phak chi	Introduced	Hb	C	Rt	Cd	Used as an ingredient in curry pastes and dipping sauces to enhance aroma.	1.043	NE	TJ-SK0002
						Sd	Sp	Used as a spice to add fragrance.
						Lf, Sd	Tm	Used as medicine.
						Lf	Vg	Eaten fresh with chili paste or used in stir-fried and boiled dishes; also sprinkled on dipping sauces to enhance aroma.
	Cuminum cyminum L.	Yi ra	Introduced	Hb	C	Lf	Sp	Leaf: Used to flavor food; Seed: Roasted and pounded to mix with curry paste.	0.489	NE	TJ-SK0015
						Lf, Rt	Tm	Used as medicine.
	Eryngium foetidum L.	Phak hom pe	Introduced	Hb	C	Lf	Vg	Eaten fresh with chili paste or used in boiled dishes.	0.609	NE	TJ-SK0028
	Oenanthe javanica (Blume) DC.	Phak chi nam	Native	Hb	C	Lf	Vg	Eaten fresh with chili paste.	0.413	LC	TJ-SK0038
Apocynaceae	Oxystelma esculentum (L.f.) Sm.	Chamuk pla lot	Native	Cl	W	Lf	Vg	Eaten fresh with chili paste.	0.348	LC	TJ-SK0043
	Telosma cordata (Burm.f.) Merr.	Khachon	Native	Cl	C	If	Vg	Boiled or eaten fresh with chili paste; also used in curry dishes.	0.511	NE	TJ-SK0013
	Urceola polymorpha (Pierre ex Spire) D.J.Middleton & Livsh.	Som lom	Native	Cl	W	Ft, Lf	Fc	Use boiled dishes to add sourness.	0.207	NE	TJ-SK0051
Araceae	Amorphophallus paeoniifolius (Dennst.) Nicolson	I buk	Native	Hb	W	Lf	Vg	The petiole is peeled and boiled to reduce itchiness before being used in curry dishes.	0.348	LC	TJ-SK0020
	Colocasia esculenta (L.) Schott	Thun	Native	Hb	W	Lf	Vg	The petiole is peeled and boiled or roasted to reduce itchiness before being used in curry dishes.	0.196	LC	TJ-SK0050
	Wolffia globosa (Roxb.) Hartog & Plas	Pham	Native	Hb	W	Wp	Vg	Used in curry dishes.	0.533	LC	TJ-SK0053
Araliaceae	Hydrocotyle umbellata L.	Phak waen kaeo	Introduced	Hb	C	Lf	Vg	Eaten fresh with chili paste.	0.250	LC	TJ-SK0069
Arecaceae	Cocos nucifera L.	Maphrao	Introduced	Tr	C	Ft	Fc	Flesh is scraped into small pieces and squeezed with coconut milk, used in both savory and sweet dishes.	0.696	NE	TJ-SK0082
						St	Vg	Young shoots used in curry dishes
Aspleniaceae	Diplazium esculentum (Retz.) Sw.	Phak kut	Native	Hb	W	Lf	Vg	Used in stir-fried dishes.	0.163	LC	TJ-SK0064
Asteraceae	Acmella oleracea (L.) R.K.Jansen	Phak khrat hua waen	Introduced	Hb	W	Lf	Vg	Used in Isan-style “Gaeng Om” (herbal curry).	0.098	NE	TJ-SK0010
	Emilia sonchifolia (L.) DC.	Phak lin pi	Native	Hb	W	Lf	Vg	Eaten fresh with chili paste.	0.120	NE	TJ-SK0011
Basellaceae	Basella alba L.	Phak plang	Native	Cl	C	Lf	Vg	Used in Isan-style “Gaeng Om”.	0.413	NE	TJ-SK0005
Bignoniaceae	Dolichandrone serrulata (Wall. ex DC.) Seem.	Khae na	Native	Tr	C	If	Vg	Boiled or eaten fresh with chili paste.	0.467	LC	TJ-SK0006
	Fernandoa adenophylla (Wall. ex G.Don) Steenis	Khae hang khang	Native	Tr	C	If	Vg	Boiled or eaten fresh with chili paste.	0.185	LC	TJ-SK0007
	Markhamia stipulata (Wall.) Seem.	Khae hua mu	Native	Tr	C	If	Vg	Boiled or eaten fresh with chili paste.	0.174	LC	TJ-SK0101
	Oroxylum indicum (L.) Kurz	Lin fa	Native	Tr	C	Ft, If	Vg	Inflorescence: Boiled or eaten fresh with chili paste; also used in Isan-style soups. Fruit: Eaten fresh with chili paste or roasted and eaten as a vegetable or used in Isan-style soups.	0.402	LC	TJ-SK0014
Brassicaceae	Brassica oleracea L. “Alboglabra”	Phak kha na	Introduced	Hb	C	Lf, St	Vg	Used in stir-fried dishes.	0.620	DD	TJ-SK0063
	Brassica rapa L.	Phak kat khao	Introduced	Hb	C	Lf	Vg	Boiled or eaten fresh as a vegetable or used in stir-fried or boiled dishes.	0.663	NE	TJ-SK0089
Capparaceae	Crateva adansonii DC.	Phak kum	Introduced	Tr	C	Lf	Vg	Made into pickled vegetables to reduce toxicity before cooking.	0.304	LC	TJ-SK0092
Caricaceae	Carica papaya L.	Bak hung	Introduced	Tr	C	Ft	Vg	Ripe fruit eaten fresh; unripe fruit used in dishes such as “Som Tam” (spicy salad) or curries.	0.880	DD	TJ-SK0093
Cleomaceae	Cleome gynandra L.	Phak sian	Native	Hb	B	If, Lf, St	Vg	Used to make pickled vegetables.	0.293	NE	TJ-SK0094
Convolvulaceae	Ipomoea alba L.	Chom chan	Introduced	Cl	C	If	Vg	Boiled and eaten with chili paste or used in stir-fried dishes.	0.315	LC	TJ-SK0095
	Ipomoea aquatica Forssk.	Phak bung	Native	Hb	C	Lf, St	Vg	Boiled and eaten with chili paste or used in stir-fried and curry dishes.	0.859	LC	TJ-SK0109
Cucurbitaceae	Benincasa hispida (Thunb.) Cogn.	Fak	Introduced	Cl	C	Ft	Vg	Used in curry dishes.	0.543	NE	TJ-SK0058
	Coccinia grandis (L.) Voigt	Phak tamlueng	Native	Cl	C	Lf	Vg	Boiled and eaten with chili paste or used in curry dishes.	0.446	NE	TJ-SK0040
	Cucumis sativus L.	Taeng kwa	Native	Cl	C	Ft	Vg	Eaten fresh with chili paste; also used in “Som Tam”, stir-fried, or boiled dishes.	0.609	NE	TJ-SK0036
	Cucurbita maxima Duchesne	Fak thong	Introduced	Cl	C	Ft, Lf	Vg	Fruit: Used in savory dishes such as Isan-style “Gaeng Om” or stir-fried dishes or used in desserts; Leaf: Boiled and eaten with chili paste or used in stir-fried dishes.	0.565	NE	TJ-SK0072
	Luffa acutangula (L.) Roxb.	Buap liam	Introduced	Cl	C	Ft	Vg	Used in Isan-style “Gaeng Om” or stir-fried dishes.	0.250	NE	TJ-SK0078
	Luffa aegyptiaca Mill.	Buap hom	Introduced	Cl	B	Ft	Vg	Boiled and eaten with chili paste or used in Isan-style “Gaeng Om”.	0.457	NE	TJ-SK0079
	Momordica charantia L.	Phak sai	Native	Cl	C	Ft	Fc	Boiled and eaten with chili paste.	0.467	NE	TJ-SK0080
						Lf	Vg	Used in Isan-style Gaeng Om to add bitterness.
	Trichosanthes cucumerina subsp. cucumerina	Buap ngu	Native	Cl	C	Ft	Vg	Boiled or eaten fresh with chili paste.	0.337	NE	TJ-SK0026
Euphorbiaceae	Cnidoscolus aconitifolius subsp. aconitifolius	Ton chai ya	Introduced	Sh	C	Lf	Fc	Used to enhance umami flavor, as a substitute for MSG.	0.315	NE	TJ-SK0001
						Lf	Vg	Used in stir-fried dishes.
Fabaceae	Hultholia mimosoides (Lam.) Gagnon & G.P.Lewis	Phak khaya	Native	Cl	W	Lf	Vg	Eaten fresh with chili paste.	0.239	LC	TJ-SK0070
	Leucaena leucocephala (Lam.) de Wit	Krachot	Introduced	Tr	B	Lf, Sd	Vg	Eaten fresh with chili paste.	0.207	NE	TJ-SK0017
	Piliostigma malabaricum (Roxb.) Benth.	Phak som siao	Native	Tr	C	Lf	Fc	Use boiled dishes to add sourness.	0.250	LC	TJ-SK0029
	Psophocarpus tetragonolobus (L.) DC.	Thua phu	Introduced	Cl	C	Ft	Vg	Eaten fresh with chili paste or used in stir-fried dishes.	0.500	NE	TJ-SK0105
	Senegalia pennata (L.) Maslin	Phak kha	Introduced	Tr	C	Lf	Fc	Used in curry dishes to add a characteristic aroma.	0.652	LC	TJ-SK0055
						Lf	Vg	Eaten fresh with chili paste.
	Senna siamea (Lam.) H.S.Irwin & Barneby	Khi lek	Native	Tr	B	Lf	Vg	Boiled to reduce bitterness before being used in curry dishes.	0.424	LC	TJ-SK0016
	Sesbania grandiflora (L.) Poir.	Khae	Introduced	Tr	C	If	Vg	Used in Isan-style “Gaeng Om” (herbal curry).	0.457	DD	TJ-SK0075
	Vigna unguiculata subsp. sesquipedalis (L.) Verdc.	Thua fak yao	Introduced	Cl	C	Ft	Vg	Boiled or eaten fresh with chili paste; also used in “Som Tam” or stir-fried dishes.	0.554	NE	TJ-SK0074
Hydrocharitaceae	Hydrocharis morsus-ranae L.	Tap tao	Introduced	Hb	W	Lf	Vg	Eaten fresh with chili paste.	0.261	LC	TJ-SK0076
Hypericaceae	Cratoxylum formosum (Jack) Benth. & Hook.f. ex Dyer	Phak tio	Native	Tr	B	If, Lf	Fc, Vg	Used in boiled or curry dishes to add sourness.	0.630	LC	TJ-SK0102
Lamiaceae	Coleus amboinicus Lour.	Hu suea	Introduced	Hb	C	Lf	Vg	Eaten fresh with chili paste.	0.228	NE	TJ-SK0077
	Mentha × villosa Huds.	Saranae	Introduced	Hb	C	Lf	Sp	Eaten fresh with chili paste or sprinkled on Isan-style “Larb” (spicy minced meat salad) to add aroma.	0.674	NE	TJ-SK0066
	Ocimum basilicum var. basilicum	Ho ra pha	Native	Hb	C	Lf	Sp	Eaten fresh with chili paste or used in curry or stir-fried dishes to enhance aroma.	0.707	NE	TJ-SK0071
	Ocimum tenuiflorum L.	Kra phrao	Native	Hb	C	Lf	Sp	Used as a seasoning to enhance aroma in stir-fried and boiled dishes.	0.859	NE	TJ-SK0003
	Ocimum × africanum Lour.	I tu	Native	Hb	C	Lf	Sp	Used as a seasoning to enhance aroma in stir-fried dishes, boiled dishes, and Isan-style “Gaeng Om”.	0.870	NE	TJ-SK0088
Lecythidaceae	Careya arborea Roxb.	Phak kradon	Native	Tr	C	Lf	Vg	Eaten fresh with chili paste.	0.402	LC	TJ-SK0085
Malvaceae	Abelmoschus esculentus (L.) Moench	Krachap khiao	Introduced	Hb	C	Ft	Vg	Boiled or eaten fresh with chili paste; also used in stir-fried dishes.	0.457	NE	TJ-SK0090
Marsileaceae	Marsilea crenata C.Presl	Phak waen	Native	Hb	W	Lf, St	Vg	Eaten fresh with chili paste.	0.446	LC	TJ-SK0091
Meliaceae	Azadirachta indica A.Juss	Sadao	Native	Tr	C	If	Vg	Boiled or eaten fresh with chili paste.	0.652	LC	TJ-SK0065
						If, Lf, Rt	Tm	Used as medicine.
Menispermaceae	Cissampelos pareira L.	Khreua ma noi	Native	Cl	C	Lf	Vg	Crushed and mixed with water, then filtered; the resulting jelly-like extract is used in cooking.	0.576	NE	TJ-SK0018
	Tiliacora triandra (Colebr.) Diels	Yanang	Native	Cl	B	Lf	Fc	Crushed and mixed with water, then filtered; used in curry dishes.	0.739	NE	TJ-SK0019
						Lf, Rt	Tm	Used as medicine.
Molluginaceae	Glinus oppositifolius (L.) Aug.DC.	Sadao din	Native	Hb	W	Lf, St	Fc	Used in Isan-style “Gaeng Om” to add bitterness.	0.315	LC	TJ-SK0023
Moraceae	Artocarpus heterophyllus Lam.	Khanun	Introduced	Tr	C	Ft	Vg	Unripe fruits are boiled and used in Isan-style soups.	0.283	NE	TJ-SK0024
	Morus alba L.	Mon	Introduced	Tr	C	Lf	Fc	Used in boiled dishes to enhance umami flavor.	0.196	LC	TJ-SK0039
Moringaceae	Moringa oleifera Lam.	Phak i hum	Introduced	Tr	C	Ft, If	Vg	Inflorescence: Used to make pickled vegetables; Fruit: Used in curry dishes.	0.620	LC	TJ-SK0027
Musaceae	Musa × paradisiaca L.	Kluai	Introduced	Hb	C	If	Vg	Eaten fresh with chili paste; used in curry or “Mok” (Isan-style steamed dishes).	0.804	NE	TJ-SK0032
Myrtaceae	Syzygium antisepticum (Blume) Merr. & L.M.Perry	Phak mek	Native	Tr	C	Lf	Vg	Eaten fresh with chili paste.	0.370	LC	TJ-SK0060
Nymphaeaceae	Nymphaea pubescens Willd.	Bua sai	Native	Hb	C	If	Vg	Young lotus stalks eaten fresh with chili paste; also used in “Som Tam” or curry dishes.	0.522	LC	TJ-SK0061
Onagraceae	Ludwigia adscendens (L.) H.Hara	Phaeng phuai nam	Native	Hb	W	Lf, St	Vg	Eaten fresh with chili paste.	0.185	LC	TJ-SK0021
Opiliaceae	Melientha suavis Pierre	Phak wan pa	Native	Tr	W	Lf	Vg	Used in curry dishes.	0.674	LC	TJ-SK0034
Passifloraceae	Adenia viridiflora Craib	Phak sap	Native	Cl	C	Ft, Lf, St	Vg	Boiled or eaten fresh with chili paste; used in curry dishes; also used to make pickled vegetables.	0.228	NE	TJ-SK0041
Phyllanthaceae	Phyllanthus androgynus (L.) Chakrab. & N.P.Balakr.	Phak wan ban	Native	Sh	C	Lf	Vg	Used in curry dishes.	0.272	NE	TJ-SK0042
Piperaceae	Peperomia pellucida (L.) Kunth	Phak kasang	Introduced	Hb	C	Lf, St	Vg	Eaten fresh with chili paste or used in curry dishes.	0.207	NE	TJ-SK0067
	Piper nigrum L.	Phrik thai	Introduced	Cl	C	Ft	Sp	Used as a spice to increase spiciness.	0.478	NE	TJ-SK0068
						Ft, Lf	Tm	Used as medicine.
	Piper sarmentosum Roxb.	Phak i loet	Native	Hb	C	Lf	Fc	Used in Isan-style “Gaeng Om” or “Mok” to enhance aroma.	0.511	NE	TJ-SK0073
						Lf	Tm	Used as medicine.
Plantaginaceae	Limnophila aromatica (Lam.) Merr.	Phak khayaeng	Introduced	Hb	W	Lf, St	Fc	Eaten fresh with chili paste or used in curry dishes to enhance aroma.	0.402	LC	TJ-SK0106
Poaceae	Bambusa nutans Wall. ex Munro	Phai bong	Native	Gs	W	St	Vg	Used in curry and stir-fried dishes; also used to make pickled vegetables.	0.228	NE	TJ-SK0033
	Bambusa spinosa Roxb.	Phai si suk	Introduced	Gs	W	St	Vg	Used in curry and stir-fried dishes; also used to make pickled vegetables.	0.239	NE	TJ-SK0057
	Cymbopogon citratus (DC.) Stapf	Ta khrai	Introduced	Gs	C	St	Sp	Used in cooking to enhance aroma.	0.739	NE	TJ-SK0047
						Wp	Tm	Used as medicine.
	Dendrocalamus asper (Schult. & Schult.f.) Backer	Phai tong	Native	Gs	W	St	Vg	Boiled and eaten as a vegetable; used in “Som Tam”, curry, stir-fried dishes, and pickled vegetables.	0.370	NE	TJ-SK0048
	Gigantochloa albociliata (Munro) Kurz	Phai rai	Native	Gs	W	St	Vg	Boiled and eaten as a vegetable; used in “Som tam”, curry, stir-fried dishes, and pickled vegetables.	0.413	NE	TJ-SK0054
	Phragmites australis (Cav.) Trin. ex Steud.	Ton or	Introduced	Gs	W	St	Vg	Used in curry dishes.	0.120	LC	TJ-SK0087
	Thyrsostachys siamensis Gamble	Phai ruak	Native	Gs	W	St	Vg	Boiled and eaten as a vegetable; used in “Som Tam”, curry, stir-fried dishes, and pickled vegetables.	0.315	NE	TJ-SK0104
	Vietnamosasa ciliata (A.Camus) T.Q.Nguyen	No choet	Introduced	Gs	W	St	Vg	Boiled and eaten as a vegetable; used in “Som Tam”, curry, and stir-fried dishes.	0.348	NE	TJ-SK0108
	Zea mays L.	Khao phot	Introduced	Gs	C	Ft	Vg	Young fruits used in stir-fried dishes.	0.783	LV	TJ-SK0097
Polygonaceae	Persicaria odorata (Lour.) Soják	Phak phaeo	Native	Hb	C	Lf	Fc	Used in curry or “Mok” (Isan-style steamed dishes) to enhance aroma.	0.837	NE	TJ-SK0098
						Lf	Vg	Eaten fresh with chili paste.
Rubiaceae	Paederia foetida L.	Tot mu tot ma	Native	Cl	W	Lf	Vg	Eaten fresh with chili paste.	0.250	NE	TJ-SK0099
Rutaceae	Aegle marmelos (L.) Corrêa	Matum	Introduced	Tr	C	Lf	Vg	Eaten fresh with chili paste.	0.304	NT	TJ-SK0100
						Ft	Tm	Used as medicine.
	Citrus × aurantiifolia (Christm.) Swingle	Bak nao	Introduced	Tr	C	Ft	Fc	Used as a seasoning to add sourness.	0.967	NE	TJ-SK0008
						Ft	Tm	Used as medicine.
	Citrus hystrix DC.	Bak kut	Native	Tr	C	Lf	Sp	Used in curry, boiled, stir-fried dishes, or larb to enhance aroma.	0.793	LC	TJ-SK0009
						Ft	Tm	Used as medicine.
Saururaceae	Houttuynia cordata Thunb.	Khao tong	Native	Hb	C	Lf	Vg	Eaten fresh with chili paste.	0.207	NE	TJ-SK0022
Solanaceae	Capsicum annuum L.	Phrik	Introduced	Hb	C	Ft	Cd	Used as an ingredient in traditional dipping sauces, including chili–fish sauce (Nam Pla Prik).	1.098	LC	TJ-SK0044
						Ft	Sp	Used to increase spiciness
	Solanum lasiocarpum Dunal	Ma uek	Native	Sh	C	Ft	Fc	Used to add sourness; used as an ingredient in chili paste.	0.228	NE	TJ-SK0045
	Solanum lycopersicum L.	Ma khuea thet	Introduced	Hb	C	Ft	Fc	Mixed into chili paste to add sourness.	0.598	NE	TJ-SK0046
						Ft	Vg	Used in “Som Tam”, boiled, stir-fried, or fried dishes.
	Solanum melongena L.	Ma khuea yao	Native	Sh	C	Ft	Vg	Eaten fresh with chili paste or used in stir-fried dishes.	0.500	NE	TJ-SK0062
	Solanum torvum Sw.	Bak khaeng	Introduced	Sh	C	Ft	Vg	Boiled or eaten fresh with chili paste; used in curry dishes.	0.457	NE	TJ-SK0112
						Ft, Lf, Rt	Tm	Used as medicine.
	Solanum virginianum L.	Ma khuea pro	Introduced	Sh	C	Ft	Vg	Boiled or eaten fresh with chili paste; used in tam, curry, or stir-fried dishes.	0.641	NE	TJ-SK0111
Zingiberaceae	Alpinia galanga (L.) Willd.	Kha	Native	Hb	C	Rz	Sp	Used in stir-fried, boiled, or curry dishes; included in curry pastes to enhance aroma.	0.761	NE	TJ-SK0086
						If	Vg	Boiled or eaten fresh with chili paste.
						Rz	Tm	Used as medicine.
	Alpinia siamensis K.Schum.	Kha	Native	Hb	C	Rz	Sp	Used in stir-fried, boiled, or curry dishes; included in curry pastes to enhance aroma.	0.783	NE	TJ-SK0084
						If	Vg	Boiled or eaten fresh with chili paste.
						Rz	Tm	Used as medicine.
	Boesenbergia rotunda (L.) Mansf.	Krachai	Native	Hb	C	Rz	Sp	Used in stir-fried or curry dishes to enhance aroma.	0.739	LC	TJ-SK0004
						Rz	Tm	Used as medicine.
	Curcuma angustifolia Roxb.	Krachiao daeng	Native	Hb	C	Lf	Vg	Boiled and eaten with chili paste.	0.489	NE	TJ-SK0030
	Curcuma longa L.	Khamin	Introduced	Hb	C	Rz	Sp	Used as an ingredient to add color to food.	0.391	DD	TJ-SK0031
						Rz	Tm	Used as medicine.
	Curcuma singularis Gagnep.	Krachiao khao	Native	Hb	W	Lf	Vg	Boiled and eaten with chili paste.	0.533	NE	TJ-SK0056
	Kaempferia marginata Carey ex Roscoe	Tub mup	Native	Hb	W	Lf	Vg	Used in yam dishes or Isan-style “Gaeng Om”.	0.337	NE	TJ-SK0025
						Rz	Tm	Used as medicine.
	Zingiber montanum (J.Koenig) Link ex A.Dietr.	Phlai	Native	Hb	C	Rz	Sp	Used in curry paste to reduce fishy odor.	0.370	NE	TJ-SK0096
						If	Vg	Eaten fresh with chili paste.
						If, Rz	Tm	Used as medicine.
	Zingiber officinale Roscoe	Khing	Introduced	Hb	C	Rz	Sp	Used as a spice to add spiciness and aroma.	0.772	DD	TJ-SK0113
						Rz	Vg	Used in stir-fried dishes; also used to make pickled vegetables served with Isan sausage.
						Rz	Tm	Used as medicine.

Abbreviation: Growth habit: climber (Cl), grass (Gs), herb (Hb), shrub (Sh), tree (Tr). Resource: both from cultivated and wild (B), cultivated (C), wild (W). Used parts: bulb (Bu), fruit (Ft), inflorescence (If), leaf (Lf), root (Rt), rhizome (Rz), seed (Sd), shoot (St), whole plant (Wp). Utilization: condiment (Cd), food ingredient or culinary additive (Fc), spice or seasoning (Sp), traditional medicine (Tm), vegetable (Vg). Conservation status: data deficient (DD), least concern (LC), not evaluated (NE).

). The documented flora reflects a high diversity of plant resources utilized in local food systems, encompassing both wild and semi-cultivated species.

Among the recorded families, Poaceae and Zingiberaceae were the most species-rich, each represented by 9 taxa, followed by Cucurbitaceae and Fabaceae with 8 taxa each, and Apiaceae with 7 taxa. Other families with moderate representation included Solanaceae (6 taxa), Lamiaceae (5 taxa), and Bignoniaceae (4 taxa). Several families—namely Amaryllidaceae, Apocynaceae, Araceae, Piperaceae, and Rutaceae—were each represented by 3 taxa, while Amaranthaceae, Asteraceae, Brassicaceae, Convolvulaceae, Menispermaceae, and Moraceae each contributed 2 taxa.

The remaining 31 families were represented by a single taxon each, including Alismataceae, Anacardiaceae, Annonaceae, Araliaceae, Arecaceae, Aspleniaceae, Basellaceae, Capparaceae, Caricaceae, Cleomaceae, Euphorbiaceae, Hydrocharitaceae, Hypericaceae, Lecythidaceae, Malvaceae, Marsileaceae, Meliaceae, Molluginaceae, Moringaceae, Musaceae, Myrtaceae, Nymphaeaceae, Onagraceae, Opiliaceae, Passifloraceae, Phyllanthaceae, Plantaginaceae, Polygonaceae, Rubiaceae, and Saururaceae. The dominance of a few highly diverse families alongside numerous families represented by single taxa highlights the broad taxonomic spectrum of local vegetables and spices and underscores the rich ethnobotanical knowledge maintained by the local communities.

3.2. Distribution, Growth Habit, and Used Parts of Local Vegetables and Spices

Of the 113 local vegetable and spice taxa recorded in Sang Kho Sub-district (Figure 2), slightly more than half were native species, accounting for 58 taxa (51.33%), while introduced species comprised 55 taxa (48.67%). This near-equal proportion reflects both the continued reliance on indigenous plant resources and the integration of introduced species into local food systems.

In terms of growth habits, herbaceous species were the most dominant, representing 52 taxa (46.02%), followed by trees with 25 taxa (22.12%). Climbers accounted for 21 taxa (18.58%), while grasses contributed 9 taxa (7.96%). Shrubs were less common, with 6 taxa (5.31%) (Figure 2). Overall, this distribution of growth habits highlights the ecological diversity of plant resources utilized as local vegetables and spices and underscores the importance of both herbaceous and woody species in local subsistence practices.

The study documented the various plant parts of local vegetables and spices utilized by the community. Leaves were the most frequently used part, accounting for 41.66% of all uses. Fruits followed with 18.89%, while inflorescences and shoots were each used in 10.56% of cases. Roots (7.78%), bulbs (4.44%), rhizomes (3.33%), seeds (1.66%), and whole plants (1.11%) were less commonly utilized (Figure 3). This pattern reflects the community’s preference for easily accessible and renewable plant parts, particularly leaves, which are commonly incorporated into culinary and medicinal applications.

3.3. Utilization of Local Plant Species

A total of 113 plant taxa were recorded in this study, reflecting diverse patterns of use across multiple functional categories. Individual plant species were often associated with more than one use category, including vegetables, spices or seasonings, food ingredients or culinary additives, condiments, and traditional medicine. Among these, vegetables represented the most frequently reported use (92 species), followed by traditional medicinal use (20 species), spices or seasonings and food ingredients or culinary additives (18 species each), while condiments were the least represented category (4 species).

3.3.1. Used as Condiment

Four plant species were documented as being used primarily as condiments, mainly to enhance flavor, aroma, and pungency in local cuisine (Table 2). Allium ascalonicum and A. sativum were commonly utilized for their bulbs, which were added to traditional dipping sauces, particularly chili–fish sauce (Nam Pla Prik). The fruit of Capsicum annuum was widely used to increase spiciness and served as a key ingredient in both dipping sauces and curry pastes. In addition, the root of Coriandrum sativum was incorporated into curry pastes and dipping sauces to enhance aroma and overall flavor. In Thailand, chili–fish sauce (Nam Pla Prik) is a highly popular condiment, commonly found in nearly every household and widely available in local restaurants, where it is typically used to enhance the spiciness and saltiness of a wide variety of dishes (Figure 4).

3.3.2. Used as a Food Ingredient or Culinary Additive

Seventeen plant species were recorded as being used as food ingredients or culinary additives, contributing distinctive tastes, aromas, and textures to local cuisine (Table 2, Figure 5). Several species were primarily used to impart sourness, including Citrus × aurantiifolia, Cratoxylum formosum, Piliostigma malabaricum, Solanum lasiocarpum, Solanum lycopersicum, Spondias mombin, and Urceola polymorpha. These species were commonly incorporated into chili pastes, boiled dishes, and curry preparations.

Leaves and young shoots of several species were used to enhance umami flavor and aroma in traditional dishes. Cnidoscolus aconitifolius subsp. aconitifolius and Morus alba were used to enhance umami taste, often serving as natural flavor enhancers. Aromatic qualities were contributed by Limnophila aromatica, Persicaria odorata, Piper sarmentosum, and Senegalia pennata, which were eaten fresh with chili paste or incorporated into curry dishes, “Mok” (Isan-style steamed dishes), and other local preparations.

Bitterness, an important taste component in Isan cuisine, was provided by Glinus oppositifolius and Momordica charantia, whose leaves and shoots were commonly used in Isan-style Gaeng om. In addition, Cocos nucifera played a multifunctional role, with the fruit flesh scraped and squeezed to obtain coconut milk, which was widely used in both savory and sweet dishes. Tiliacora triandra was also notable for its leaves, which were crushed, mixed with water, filtered, and then used as an ingredient in curry dishes, reflecting traditional culinary knowledge and processing techniques.

3.3.3. Used as a Spice or Seasoning

A total of 18 plant species were recorded as being used as spices or seasonings, playing an essential role in enhancing aroma, pungency, color, and overall flavor in local cuisine (Table 2, Figure 6). Bulbs of Allium ascalonicum and A. sativum were widely used as basic spices in stir-fried dishes to enhance aroma. Rhizomatous species, particularly members of the Zingiberaceae, were prominent, including Alpinia galanga, Alpinia siamensis, Boesenbergia rotunda, Curcuma longa, Zingiber montanum, and Z. officinale. These species were commonly incorporated into stir-fried, boiled, and curry dishes, as well as curry pastes, where they contributed distinctive aromas, spiciness, color, or helped reduce undesirable fishy odors.

Fruits and seeds were also important components of the spice repertoire. The fruit of Capsicum annuum and Piper nigrum was used to increase spiciness, while seeds of Coriandrum sativum were valued for their fragrance, and seeds of Cuminum cyminum were roasted and pounded for inclusion in curry pastes. Leaves and pseudostems of aromatic species further enrich culinary preparations. Leaves of Citrus hystrix, Ocimum basilicum, Ocimum tenuiflorum, Ocimum × africanum, and Mentha × villosa were commonly used fresh or cooked to enhance aroma in curries, stir-fried dishes, boiled dishes, Larb, and Isan-style Gaeng om. In addition, the pseudostem of Cymbopogon citratus was widely used in cooking to impart a characteristic fragrance.

Overall, spices and seasonings recorded in this study reflect a strong reliance on aromatic herbs and rhizomes, highlighting the importance of sensory qualities—particularly aroma and spiciness—in traditional and contemporary local food practices.

3.3.4. Used as Vegetables

A high diversity of plant species was documented as being used as vegetables, reflecting their central role in daily food consumption and traditional cuisine (Table 2, Figure 7). These species were consumed in a wide range of forms, including fresh, boiled, stir-fried, pickled, or incorporated into curries, soups, Som Tam, and Isan-style dishes such as Gaeng Om and Mok. Many vegetables were commonly eaten fresh or lightly processed and served with chili paste, indicating a strong preference for retaining natural taste, texture, and freshness.

Leaves, shoots, inflorescences, fruits, and young bamboo shoots were the most frequently utilized plant parts. Leafy vegetables such as Amaranthus blitum, Amaranthus viridis, Centella asiatica, Houttuynia cordata, and Ipomoea aquatica were widely consumed either fresh or cooked, while inflorescences of species such as Azadirachta indica, Dolichandrone serrulata, Sesbania grandiflora, and Telosma cordata were boiled or eaten fresh with chili paste. Fruits of several species, including Carica papaya, Cucumis sativus, Solanum spp., and Trichosanthes cucumerina, were eaten raw, boiled, or used in curries and salads.

Bamboo shoots from multiple genera (Bambusa, Dendrocalamus, Gigantochloa, Thyrsostachys, and Vietnamosasa) represented an important vegetable resource and were prepared in diverse ways, including boiling, stir-frying, pickling, and incorporation into curries and Som Tam. Some species required specific processing techniques to improve palatability or reduce bitterness and irritation, such as boiling leaves of Senna siamea, peeling and boiling petioles of Colocasia esculenta, or preparing pickled products from Crateva adansonii and Cleome gynandra.

Overall, the wide range of plant taxa, edible parts, and preparation methods recorded in this category highlights the richness of local ethnobotanical knowledge and underscores the importance of vegetables derived from both cultivated and wild sources in supporting dietary diversity and food security.

3.3.5. Used as Traditional Medicine

A total of 20 plant species were recorded as being used in traditional medicine, representing a diverse assemblage of taxa commonly integrated into local healthcare practices (Table 2, Figure 8). These species belong to multiple botanical families, with a notable representation of aromatic and medicinally important groups, particularly the Zingiberaceae, including Alpinia, Boesenbergia, Curcuma, and Zingiber. Several species used as traditional medicine were also common culinary plants, such as Allium ascalonicum, A. sativum, Coriandrum sativum, Cuminum cyminum, Citrus spp., and Piper spp., highlighting the close connection between food and medicine in local knowledge systems.

3.4. Cultural Importance Index (CI) of Local Vegetables and Spices

The Cultural Importance Index (CI) was used to evaluate the relative cultural significance of local vegetables and spices based on their frequency of citation and diversity of uses within the community (Table 2). CI values varied considerably among taxa, reflecting differences in culinary, medicinal, and cultural relevance.

The highest CI value was recorded for Allium ascalonicum (CI = 1.152), followed by Capsicum annuum (CI = 1.098) and Coriandrum sativum (CI = 1.043), indicating their prominent roles in daily food preparation and traditional practices. Other highly valued species included Citrus × aurantiifolia (CI = 0.967), Ipomoea aquatica (CI = 0.859), Ocimum tenuiflorum (CI = 0.859), Ocimum × africanum (CI = 0.870), Persicaria odorata (CI = 0.837), and Musa × paradisiaca (CI = 0.804), all of which are widely utilized and culturally embedded in local livelihoods.

Moderate CI values were observed for a broad range of commonly consumed vegetables and spices, such as Carica papaya (CI = 0.880), Cocos nucifera (CI = 0.696), Anethum graveolens (CI = 0.685), Mentha × villosa (CI = 0.674), Melientha suavis (CI = 0.674), Brassica rapa (CI = 0.663), Senegalia pennata (CI = 0.652), and Azadirachta indica (CI = 0.652), reflecting their multifunctional roles in food, medicine, and cultural practices.

Lower CI values were recorded for species with more restricted or specialized uses, including Annona squamosa (CI = 0.054), Acmella oleracea (CI = 0.098), Emilia sonchifolia (CI = 0.120), and Phragmites australis (CI = 0.120), suggesting limited cultural prominence or narrower application within the study area.

Overall, the CI analysis highlights a small number of highly dominant taxa that play central roles in local food systems and ethnomedicinal knowledge, alongside a larger pool of species with moderate to low cultural significance that contribute to dietary diversity and traditional ecological knowledge.

3.5. Ethnomedicinal of Local Vegetables and Spices

3.5.1. Condition of Plants Used and Routes of Administration

The condition of plant materials used in traditional practices reflects local preferences and practical strategies in the utilization of vegetables and spices (

Table 3. Traditional medicinal uses of recorded plant species, showing scientific name, Fidelity Level (FL), plant parts used, condition of plants used (CoP), preparation methods, routes of administration (RoA), therapeutic applications, and therapeutic categories.

Scientific Name	FL	Plant Parts Used	CoP	Preparation Methods	RoA	Therapeutic Applications	Therapeutic Categories
Aegle marmelos (L.) Corrêa	71.43	Fruit	Dry	The fruits are cut into slices, dried in the sun, decocted in water, and the filtrate is taken orally as a traditional remedy.	Oral	Traditionally used for the management of diarrhea, dysentery, and stomach-related ailments.	Gastrointestinal Disorder
	28.57	Fruit	Dry	The fruits are cut into slices, dried in the sun, decocted in water, and the filtrate is taken orally as a traditional remedy.	Oral	Traditionally used as an expectorant to reduce phlegm.	Respiratory Disorder
Allium ascalonicum L.	50.00	Bulb	Fresh	The material is decocted in water, filtered, and the resulting liquid is taken orally.	Oral	Traditionally used as a carminative to alleviate abdominal distension.	Gastrointestinal Disorder
	25.00	Bulb	Fresh	The material is decocted in water, filtered, and the resulting liquid is taken orally.	Oral	Traditionally used to expel intestinal parasites.	Infection, Parasite, and Immune Disorder
	25.00	Bulb	Fresh	The material is crushed and applied externally to the affected site.	Dermal	Traditionally used to counteract toxins from insect and animal bites and stings.	Poisoning and Toxicology
Allium sativum L.	50.00	Bulb	Fresh	Five to seven garlic cloves are crushed, combined with two tablespoons of vinegar, a pinch of salt, and sugar, and the mixture is strained; only the filtrate is taken orally as a traditional remedy.	Oral	Traditionally used to relieve colicky pain and abdominal distension.	Gastrointestinal Disorder
	30.00	Bulb	Fresh	The garlic bulbs are finely grated or crushed, applied topically to the affected skin, covered with a bandage for a minimum of 20 min, then rinsed with clean water. This procedure is performed twice daily.	Dermal	Traditionally used for the treatment of dermatophytic fungal infections (ringworm and tinea).	Integumentary Disorder
	20.00	Bulb	Fresh	Fresh garlic is eaten raw as a traditional remedy.	Oral	Traditionally used to reduce hyperlipidemia, lower hypertension, and manage conditions related to coronary and cerebral vascular occlusion.	Circulatory Disorder
Alpinia galanga (L.) Willd.	60.00	Rhizome	Fresh	The material is crushed thoroughly, combined with clear limewater, and the resulting liquid is taken orally as a traditional remedy.	Oral	Traditionally used to relieve gastrointestinal disorders, including abdominal fullness, bloating, flatulence, and diarrhea.	Gastrointestinal Disorder
	40.00	Rhizome	Fresh	The material is crushed thoroughly, combined with local rice liquor to form a moist paste, and both the solid and liquid components are applied externally to urticaria-affected areas several times daily until symptoms subside.	Dermal	Traditionally used for the treatment of urticaria (allergic skin eruptions).	Integumentary Disorder
Alpinia siamensis K.Schum.	66.67	Rhizome	Fresh	The material is crushed thoroughly, combined with clear limewater, and the resulting liquid is taken orally as a traditional remedy.	Oral	Traditionally used to relieve gastrointestinal disorders, including abdominal fullness, bloating, flatulence, and diarrhea.	Gastrointestinal Disorder
	33.33	Rhizome	Fresh	The material is crushed thoroughly, combined with local rice liquor to form a moist paste, and both the solid and liquid components are applied externally to urticaria-affected areas several times daily until symptoms subside.	Dermal	Traditionally used for the treatment of urticaria (allergic skin eruptions).	Integumentary Disorder
Azadirachta indica A.Juss	50.00	Leaf	Fresh	The material is decocted in water, filtered, and the resulting liquid is taken orally.	Oral	Traditionally used for body detoxification and the elimination of residual toxins.	Poisoning and Toxicology
	25.00	Inflorescence	Fresh	The material is blanched and consumed as a vegetable accompaniment with chili paste.	Oral	Traditionally used as an antipyretic to alleviate fever and excessive body heat.	Infection, Parasite, and Immune Disorder
	25.00	Root	Fresh	The material is decocted in water, filtered, and the resulting liquid is taken orally.	Oral	Traditionally used for the treatment of cough.	Respiratory Disorder
Boesenbergia rotunda (L.) Mansf.	60.00	Rhizome	Fresh	The material is roasted, finely crushed, mixed thoroughly with clear limewater, and the expressed liquid is taken orally as a traditional remedy.	Oral	Traditionally used for the management of dysentery and diarrheal conditions.	Gastrointestinal Disorder
	40.00	Rhizome	Fresh	The rhizomes are washed, air-dried, sliced into thin pieces, and ground into a coarse powder. Vegetable oil is gently heated and mixed with the rhizome powder at a ratio of three parts oil to one part rhizome. The mixture is simmered over low heat for approximately 15–20 min with constant stirring to prevent burning. Afterward, the plant residue is filtered out, and the infused oil is stored in an amber glass bottle and used topically to treat ringworm and tinea infections.	Dermal	Traditionally used for the treatment of fungal skin infections (ringworm and tinea).	Integumentary Disorder
Citrus × aurantiifolia (Christm.) Swingle	57.14	Fruit	Fresh	The expressed fruit juice is combined with a pinch of salt and taken orally as a traditional remedy.	Oral	Traditionally used for the treatment of cough and sore throat.	Respiratory Disorder
	42.86	Fruit	Fresh	The expressed fruit juice is combined with a pinch of salt and taken orally as a traditional remedy.	Oral	Traditionally used as an expectorant to reduce phlegm.	Respiratory Disorder
Citrus hystrix DC.	62.50	Fruit	Fresh	Fresh peel is thinly sliced (approximately one tablespoon), combined with a small amount of camphor or borneol, infused in boiling water, allowed to steep, and the infusion is taken orally.	Oral	Traditionally used as a carminative to alleviate intestinal gas and abdominal distension.	Gastrointestinal Disorder
	37.50	Fruit	Fresh	Fresh peel is thinly sliced (approximately one tablespoon), combined with a small amount of camphor or borneol, infused in boiling water, allowed to steep, and the infusion is taken orally.	Oral	Traditionally used to purify menstrual blood and act as an emmenagogue.	Obstetrics, Gynecology and Urinary Disorders
Coriandrum sativum L.	62.50	Seed	Fresh	The seeds are macerated in alcohol for about two weeks, and the resulting preparation is taken orally at a dosage of one to two shot-sized servings per day over several days.	Oral	Traditionally used to relieve abdominal pain due to internal cold conditions and to support digestive health.	Gastrointestinal Disorder
	25.00	Leaf	Fresh	The material is crushed and applied to the temples as a cooling topical application.	Dermal	Traditionally used for the treatment of headaches.	Neurological Disorder
	12.50	Leaf	Fresh	The extracted juice is used for external application on the skin.	Dermal	Traditionally used for the management of inflammatory and pruritic skin rashes.	Integumentary Disorder
Cuminum cyminum L.	57.14	Root	Dry	The material is decocted in water, filtered, and the resulting liquid is taken orally.	Oral	Traditionally used to improve digestive system function and to treat gastrointestinal disorders, including bloating, flatulence, abdominal pain, and diarrhea.	Gastrointestinal Disorder
	42.86	Leaf	Dry	The material is decocted in water, filtered, and the resulting liquid is taken orally.	Oral	Traditionally used to alleviate dysmenorrhea.	Obstetrics, Gynecology and Urinary Disorders
Curcuma longa L.	41.67	Rhizome	Dry	The powder is blended with honey and shaped into small bolus pills.	Oral	Traditionally used for the treatment of diarrhea.	Gastrointestinal Disorder
	33.33	Rhizome	Dry	The powder is blended with honey and shaped into small bolus pills.	Oral	Used to alleviate abdominal bloating and discomfort.	Gastrointestinal Disorder
	25.00	Rhizome	Dry	The powdered material is applied topically to the skin.	Dermal	Used to nourish and enhance skin health.	Integumentary Disorder
Cymbopogon citratus (DC.) Stapf	75.00	Whole plant	Fresh	The material is decocted in water, filtered, and the resulting liquid is taken orally.	Oral	Traditionally used to treat epigastric distension and gastrointestinal discomfort.	Gastrointestinal Disorder
	25.00	Whole plant	Fresh	The material is decocted in water, filtered, and the resulting liquid is taken orally.	Oral	Traditionally used to alleviate joint and muscular pain, contusions resulting from falls, and edema of the lower limbs.	Musculoskeletal Disorder
Kaempferia marginata Carey ex Roscoe	57.14	Rhizome	Fresh	The material is crushed thoroughly and applied topically as a poultice to the affected skin.	Dermal	Traditionally used to reduce inflammatory reactions resulting from insect and animal bites and stings.	Poisoning and Toxicology
	42.86	Rhizome	Fresh	The material is sun-dried and subsequently decocted in water to be taken orally.	Oral	Traditionally used for the treatment of fever and the common cold.	Infection, Parasite, and Immune Disorder
Piper nigrum L.	40.00	Fruit	Fresh	The material is decocted in water and filtered; the liquid is consumed orally as a traditional remedy or incorporated into culinary preparations.	Oral	Traditionally used to alleviate gastrointestinal gas, reduce bloating, and promote appetite.	Gastrointestinal Disorder
	40.00	Fruit	Fresh	The material is decocted in water and filtered; the liquid is consumed orally as a traditional remedy or incorporated into culinary preparations.	Oral	Traditionally used for the management of asthma and asthmatic symptoms.	Respiratory Disorder
	20.00	Leaf	Fresh	The material is decocted in water, filtered, and the resulting liquid is taken orally.	Oral	Traditionally used to alleviate colicky pain, abdominal fullness, and gastrointestinal discomfort.	Gastrointestinal Disorder
Piper sarmentosum Roxb.	55.56	Leaf	Fresh	Consumed as a fresh vegetable served with chili paste or incorporated into various culinary dishes.	Oral	Traditionally used as an appetite stimulant.	Gastrointestinal Disorder
	22.22	Leaf	Fresh	Consumed as a fresh vegetable served with chili paste, or incorporated into various culinary dishes.	Oral	Traditionally used to support bone and dental health.	Gastrointestinal Disorder
	22.22	Leaf	Fresh	Consumed as a fresh vegetable served with chili paste, or incorporated into various culinary dishes.	Oral	Traditionally used as an expectorant to relieve phlegm accumulation in the chest and throat.	Respiratory Disorder
Solanum torvum Sw.	57.14	Fruit	Dry	The material is sun-dried and subsequently decocted in water to be taken orally.	Oral	Traditionally used for alleviating contusions and muscular pain.	Musculoskeletal Disorder
	28.57	Root	Dry	The material is sun-dried and subsequently decocted in water to be taken orally.	Oral	Traditionally used for body detoxification.	Poisoning and Toxicology
	14.29	Leaf	Fresh	Crushed thoroughly and applied as a compress to the skin.	Dermal	Traditionally used for wound healing, abscess treatment, and to facilitate wound drying.	Integumentary Disorder
Tiliacora triandra (Colebr.) Diels	66.67	Leaf	Fresh	Leaves are macerated in water to extract chlorophyll, filtered, and the resulting liquid is taken orally as a traditional remedy.	Oral	Traditionally used as an antipyretic for various febrile conditions, such as typhoid fever, toxic fever, lethargic fever, and fever accompanied by headache.	Infection, Parasite, and Immune Disorder
	33.33	Root	Fresh	The material is decocted in water, filtered, and the resulting liquid is taken orally.	Oral	Traditionally used to alleviate alcohol poisoning and hangover-related discomfort.	Poisoning and Toxicology
Zingiber montanum (J.Koenig) Link ex A.Dietr.	71.43	Rhizome	Fresh	The material is boiled in water and used as a medicinal bath.	Dermal	Traditionally used to improve blood flow and circulation in women after childbirth.	Obstetrics, Gynecology and Urinary Disorders
	28.57	Inflorescence	Fresh	The material is sun-dried and subsequently decocted in water for oral consumption, or alternatively eaten fresh as a vegetable.	Oral	Traditionally used as an emmenagogue to regulate menstrual flow and remove retained or impure blood.	Obstetrics, Gynecology and Urinary Disorders
Zingiber officinale Roscoe	60.00	Rhizome	Fresh	The material is sun-dried and subsequently decocted in water to be taken orally.	Oral	Traditionally used for the treatment of common cold and cough.	Respiratory Disorder
	40.00	Rhizome	Fresh	The material is sun-dried and subsequently decocted in water to be taken orally.	Oral	Traditionally used to alleviate gastrointestinal discomfort, including bloating, distension, colic, and abdominal pain.	Gastrointestinal Disorder

, Figure 9). Fresh plant materials were overwhelmingly predominant, accounting for 81.25% of the reported uses. This strong preference for fresh materials indicates a reliance on readily accessible plants harvested directly from home gardens, local markets, and surrounding landscapes. The use of fresh plant parts is closely associated with the preservation of natural flavor, aroma, and perceived therapeutic efficacy. In contrast, 18.75% of the plant materials were used in dried form, mainly for purposes of long-term storage, convenience in preparation, or for remedies requiring decoction. Drying was particularly important for species with limited seasonal availability or those incorporated into traditional medicinal preparations.

Regarding routes of administration, oral administration was the dominant mode, representing 77.08% of the recorded applications (Table 3, Figure 9). Most remedies were prepared as decoctions, infusions, or consumed directly as food or condiments, highlighting the close integration between culinary practices and traditional medicine, where vegetables and spices function simultaneously as food ingredients and therapeutic agents. Dermal application accounted for 22.92% of the uses and typically involved the external application of crushed, macerated, or decocted plant materials to treat skin-related conditions, inflammation, wounds, or musculoskeletal discomfort. These findings emphasize the dual culinary–medicinal roles of local vegetables and spices and reflect a holistic approach to health management within the community.

3.5.2. Fidelity Level (%FL) of Local Vegetables and Spices

The Fidelity Level (%FL) analysis revealed distinct patterns in the consistency of ethnomedicinal knowledge associated with local vegetables and spices. Overall, %FL values ranged from 11.11% to 75.00%, indicating varying degrees of agreement among informants regarding the specific therapeutic uses of individual plant species (Table 3).

Several species exhibited high fidelity levels (≥60%), reflecting a strong consensus on their primary medicinal applications. Cymbopogon citratus showed the highest %FL (75.00%) for the treatment of gastrointestinal discomfort, particularly epigastric distension. Similarly, Aegle marmelos (71.43%) was predominantly cited for managing diarrhea and dysentery, while Zingiber montanum (71.43%) was consistently used in postpartum care to improve blood circulation. Other species with high %FL values included Alpinia siamensis (66.67%), Tiliacora triandra (66.67%), Zingiber officinale (60.00%), Alpinia galanga (60.00%), and Boesenbergia rotunda (60.00%), most of which were strongly associated with gastrointestinal, febrile, or postpartum-related disorders.

Moderate %FL values (40.00–59.99%) were commonly observed among multipurpose species such as Allium sativum, Piper nigrum, Piper sarmentosum, Citrus hystrix, Solanum torvum, and Kaempferia marginata. These plants were reported for a broader range of ailments, including gastrointestinal, respiratory, integumentary, and poisoning-related disorders, resulting in a more dispersed distribution of use reports across therapeutic categories.

Lower %FL values (<40.00%) were generally associated with secondary or less frequently cited uses, such as dermatological applications, circulatory support, or detoxification purposes. This pattern suggests that while many local vegetables and spices serve multiple medicinal roles, informant agreement tends to concentrate on one dominant therapeutic use per species.

Overall, the %FL results highlight that local vegetables and spices are not only important dietary components but also culturally salient medicinal resources, with certain species demonstrating strong, well-established ethnomedicinal roles within the community.

3.5.3. Informant Consensus Factor (FIC) of Local Vegetables and Spices

The Informant Consensus Factor (FIC) was calculated to assess the degree of agreement among informants regarding the medicinal use of local vegetables and spices across different therapeutic categories (

Table 4. Informant Consensus Factor (FIC) of local vegetables and spices in Sang Kho Sub-district, Phu Phan District, Sakon Nakhon Province, Thailand.

Therapeutic Categories	Number of Use Report (Nur)	Number of Taxa (Nt)	FIC
Circulatory Disorders	2	1	1.00
Neurological Disorders	2	1	1.00
Poisoning and Toxicology	8	2	0.86
Musculoskeletal Disorders	8	2	0.86
Obstetrics, Gynecology and Urinary Disorders	13	3	0.83
Gastrointestinal Disorders	70	14	0.81
Respiratory Disorders	23	6	0.77
Infection, Parasite, and Immune Disorders	11	4	0.70
Poisoning and Toxicology	6	3	0.60
Integumentary Disorders	16	7	0.60

). In this study, FIC values ranged from 0.60 to 1.00, indicating an overall moderate to high level of shared ethnomedicinal knowledge within the study community.

The highest FIC values (1.00) were recorded for circulatory disorders and neurological disorders, each represented by two use reports (N_ur = 2) involving a single taxon (N_t = 1), suggesting complete consensus among informants on the plant species used to treat these conditions. High levels of agreement were also observed for poisoning and toxicology and musculoskeletal disorders (FIC = 0.86), each supported by eight use reports and two taxa, reflecting strong consistency in plant selection.

Moderately high consensus was found for obstetrics, gynecology, and urinary disorders (FIC = 0.83; N_ur = 13, N_t = 3) and gastrointestinal disorders (FIC = 0.81), the latter being the most prominent category in terms of use frequency (N_ur = 70) and taxonomic diversity (N_t = 14), underscoring its central role in local healthcare practices. Respiratory disorders showed slightly lower agreement (FIC = 0.77; N_ur = 23, N_t = 6), while infection, parasite, and immune disorders exhibited moderate consensus (FIC = 0.70; N_ur = 11, N_t = 4).

Lower FIC values (0.60) were recorded for poisoning and toxicology (N_ur = 6, N_t = 3) and integumentary disorders (N_ur = 16, N_t = 7), indicating greater variability in the plant taxa employed for these therapeutic uses.

4. Discussion

4.1. Local Vegetables and Spices as Foundations of Sustainable Food Systems

The diversity of local vegetables and spices documented in Sang Kho Sub-district shows a family-level pattern comparable to previous studies on home-garden vegetables in Pa Tio District, Yasothon Province [3]. In both areas, frequently used species are mainly drawn from the families Zingiberaceae, Cucurbitaceae, Fabaceae, and Apiaceae, which are well known for their culinary relevance and nutritional contributions within Northeastern Thai food systems. This similarity likely reflects shared cultural preferences, comparable agroecological conditions, and long-established food traditions across the region. The coexistence of a few species-rich families alongside a large number of families represented by single taxa highlights the broad taxonomic spectrum of plants incorporated into local food systems. Such patterns, where both dominant families and many smaller families contribute to edible plant diversity, have also been observed in other ethnobotanical surveys of edible plants in northeastern Thailand, emphasizing the multifunctional roles of diverse plant taxa in sustaining local food practices and nutritional security [27]. This broad utilization reflects not only availability and ecological distribution but also accumulated ethnobotanical knowledge that informs plant selection for culinary, cultural, and subsistence purposes.

Plant diversity contributes to local diets by supporting dietary diversity, which is widely recognized as an important component of nutritional adequacy. The use of species from multiple plant families provides access to a range of macronutrients, micronutrients, and bioactive compounds [28]. For example, members of the Zingiberaceae are particularly rich in well-documented bioactive compounds, including curcuminoids (e.g., curcumin), flavonoids such as kaempferol and quercetin, and volatile constituents such as gingerols, shogaols, and zingerone. These compounds are commonly associated with antioxidant and anti-inflammatory activities, digestive support, and antimicrobial properties, helping to explain the prominent role of Zingiberaceae species in local diets and culinary traditions [29]. In addition, vegetables and spices from families such as Apiaceae and Lamiaceae are also associated with functional properties that may enhance the nutritional quality of traditional diets [30]. These observations are consistent with previous studies linking ethnobotanical diversity with nutritional stability in rural food systems [31].

From a food security perspective, the use of wild and semi-cultivated species contributes to household-level food availability and accessibility [32], particularly during periods of seasonal scarcity or economic constraint [33]. Continued reliance on locally sourced vegetables and spices also reflects elements of food sovereignty, as communities maintain control over food choices and production practices that align with cultural preferences [34]. Moreover, many locally used species are adapted to variable environmental conditions, which may support the adaptive capacity of local food systems under changing climatic conditions [35]. Overall, these findings highlight the importance of conserving plant diversity and traditional knowledge as components of sustainable food systems in northeastern Thailand [36].

4.2. Species Composition and Plant-Use Strategies in Local Food Systems

The nearly equal proportion of native and introduced plant species recorded in Sang Kho Sub-district reflects a dynamic local food system that integrates indigenous plant resources with introduced taxa. Similar patterns have been reported in recent ethnobotanical studies conducted in Maha Sarakham Province, northeastern Thailand, where both wild and cultivated species contribute to dietary diversity and cultural identity in rural food systems [37].

The predominance of herbaceous species corresponds with trends commonly reported in ethnobotanical research, where fast-growing and easily harvested plants dominate subsistence-oriented food systems [38]. The presence of trees and climbers further indicates the multifunctional role of woody plants, which contribute both edible products and ecological functions.

Patterns of plant-part use suggest sustainability-oriented harvesting practices. The preference for leaves, fruits, and shoots—renewable plant parts—aligns with observations from other ethnobotanical studies, where selective harvesting helps maintain plant populations and long-term resource availability [39]. Such practices reflect traditional ecological knowledge that balances food use with conservation.

4.3. Utilization Patterns of Local Vegetables and Spices Within Traditional Food Systems

Vegetables constitute the primary utilization category, underscoring the central role of plant-based foods in daily diets and local food culture. Similar reliance on leafy vegetables and other plant foods has been reported in ethnobotanical studies from Southeast Asia, where they contribute substantially to dietary diversity and micronutrient intake [40,41].

Condiments are represented by fewer species but play a culturally significant role in shaping flavor and aroma. Plants such as Allium spp. and Capsicum annuum are used in small quantities yet remain essential components of local cuisine, as noted in studies of Thai and Lao food traditions [42]. The widespread use of chili–fish sauce (Nam Pla Prik) illustrates how a limited number of species underpin strong culinary preferences and local identity.

Plants used as food ingredients or culinary additives reflect the Isan people’s preference for foods characterized by diverse taste profiles. Sour, umami, bitter, and aromatic species are combined in specific dishes, emphasizing flavor balance rather than reliance on a single dominant taste [43]. This pattern reflects the availability of diverse plant resources that support nuanced and well-balanced local cuisines [44]. The processing of species such as Cocos nucifera and Tiliacora triandra further demonstrates the integration of food preparation techniques and ethnobotanical knowledge [45,46].

Spices and seasonings, particularly rhizomatous members of the Zingiberaceae, contribute substantially to the sensory characteristics of local dishes. Previous phytochemical and ethnobotanical studies indicate that many of these species contain bioactive compounds associated with antioxidant and anti-inflammatory activity, suggesting an overlap between culinary and health-related uses [47].

4.4. Cultural Significance of Local Vegetables and Spices in Community Food Systems

CI analysis indicates that a small number of species hold particularly prominent roles in local food practices. Species with high CI values, including Allium ascalonicum, Capsicum annuum, and Coriandrum sativum, are frequently used and multifunctional, reflecting their importance in everyday cooking [48,49]. Similar patterns have been observed in other studies from northeastern Thailand, where commonly used culinary plants rank highly in cultural importance [3].

Species with moderate CI values, such as Carica papaya, Cocos nucifera, and Mentha × villosa, contribute to food, flavor, and traditional remedies, supporting household food use across seasons [50,51]. In contrast, species with lower CI values tend to have more specialized or occasional uses, possibly influenced by availability or cultural preference [52]. Together, these patterns suggest that cultural importance is shaped by frequency of use, accessibility, and cultural familiarity.

4.5. Ethnomedicinal Roles of Local Vegetables and Spices

Ethnomedicinal practices in Sang Kho Sub-district illustrate close links between food and health. The preference for fresh plant materials reflects reliance on accessible resources and perceptions regarding freshness, flavor, and therapeutic value [53]. The use of dried materials indicates adaptive strategies for storage and seasonal continuity of medicinal practices [54].

Oral administration predominates, highlighting the integration of medicinal practices into daily diets through decoctions, infusions, and food-based remedies [55]. Dermal applications, although less frequent, are used for localized conditions, reflecting practical and targeted healthcare strategies [56].

High %FL values for certain species indicate strong agreement on specific medicinal uses, particularly for gastrointestinal and postpartum-related conditions. Species with lower or moderate %FL values tend to be used for a wider range of ailments, resulting in more variable reporting [57,58]. FIC values further suggest moderate to high levels of shared knowledge across major therapeutic categories, while lower consensus in some categories reflects flexibility in plant selection [59,60].

Overall, the ethnomedicinal use of local vegetables and spices reflects culturally embedded practices that contribute to everyday healthcare, dietary diversity, and knowledge transmission within rural communities of northeastern Thailand.

4.6. Conservation Status of Local Vegetables and Spices

The inclusion of conservation status in Table 2 adds an important conservation dimension to the ethnobotanical assessment of local vegetables and spices in Sang Kho Sub-district. The majority of recorded taxa are classified as Least Concern (LC), which reflects their status as commonly cultivated or widely available food plants that are not currently considered at high risk of extinction. These species are typically maintained through home gardens, small-scale cultivation, and regular market circulation, supporting their continued availability and population stability.

The predominance of LC species indicates that everyday food practices in the study area rely largely on resilient and well-established plant resources rather than on rare or threatened taxa. This pattern suggests a form of sustainable resource use in which frequently consumed vegetables and spices are drawn from species with broad availability and high adaptability, thereby reducing pressure on vulnerable wild plant populations.

Importantly, the classification of many taxa as LC does not diminish their ethnobotanical or cultural significance. On the contrary, their repeated use and high cultural importance highlight the central role of common plant resources in sustaining traditional food systems and household wellbeing. In addition, species categorized as Not Evaluated (NE) point to gaps in formal conservation assessment, particularly for locally important food plants that may not yet have been systematically evaluated.

4.7. Suggestions for Future Research

This study provides a baseline understanding of the diversity, utilization, cultural significance, and ethnomedicinal roles of local vegetables and spices in Sang Kho Sub-district. However, several directions for future research may further strengthen and expand these findings. First, comparative studies across additional districts or provinces in northeastern Thailand would help clarify regional similarities and variations in plant use patterns, cultural importance, and ethnomedicinal knowledge. Such comparisons could improve understanding of how ecological, cultural, and socioeconomic factors influence local food systems.

Second, integrating quantitative nutritional analyses and phytochemical assessments with ethnobotanical data would allow for a more detailed evaluation of the nutritional contributions and potential health-related properties of commonly used species. This approach could help link traditional knowledge with scientific evidence while remaining sensitive to local contexts.

Third, future studies could examine seasonal availability, harvesting intensity, and management practices of wild and semi-cultivated species to better understand their sustainability and long-term availability. This would be particularly relevant in assessing how local food systems respond to environmental variability and climate-related challenges.

Finally, research focusing on knowledge transmission across generations, including the roles of age, gender, and livelihood strategies, could provide insights into the continuity and potential transformation of ethnobotanical knowledge. Such perspectives would be valuable for informing conservation efforts, community-based food system initiatives, and policies aimed at supporting sustainable and culturally appropriate food practices in northeastern Thailand.

5. Conclusions

This study presents a comprehensive ethnobotanical assessment of local vegetables and spices used in Sang Kho Sub-district, Sakon Nakhon Province, northeastern Thailand. By integrating systematic field surveys, voucher-based plant identification, ethnobotanical interviews, and quantitative analytical indices, the research documents a rich diversity of wild, semi-domesticated, and cultivated plant species that underpin local food practices, seasoning traditions, and household health systems.

The application of the Cultural Importance Index (CI) identifies a small group of highly dominant taxa—such as Allium ascalonicum, Capsicum annuum, and Coriandrum sativum—that play central roles in everyday cooking, flavor construction, and associated cultural practices. At the same time, a broader assemblage of species with moderate to low CI values contributes to dietary diversity, seasonal food security, and the ongoing transmission of traditional ecological knowledge. This pattern highlights the multifunctionality of local plant resources, which serve simultaneously as vegetables, spices, condiments, culinary additives, and components of household remedies.

Quantitative analyses of medicinal plant use reveal varying levels of knowledge consensus within the community. High Informant Consensus Factor (FIC) values for circulatory and neurological disorder categories indicate well-shared and culturally robust ethnomedicinal knowledge. Fidelity Level (FL) further identifies species with particularly specific therapeutic associations, with Cymbopogon citratus exhibiting the highest FL value (75%). Together, these indices illustrate the close integration of food and medicine within local plant use systems, reflecting a holistic understanding of health, nutrition, and everyday wellbeing.

Despite increasing access to commercially produced vegetables and packaged spices, traditional plant-based food practices continue to be actively maintained in Sang Kho Sub-district. Home gardens, community forests, fallow lands, and local markets function as key arenas for both the practice and intergenerational transmission of ethnobotanical knowledge. The persistence of these practices indicates an adaptive local food system in which traditional species and culinary knowledge currently coexist with introduced ingredients.

Overall, the findings emphasize the importance of local vegetables and spices as both cultural and biological resources. Documenting and quantitatively evaluating their uses enriches the ethnobotanical record of northeastern Thailand and provides baseline information relevant to cultural heritage conservation, sustainable plant resource management, and the resilience of community-based food systems. Recognizing and supporting traditional knowledge systems remains essential for informed biodiversity conservation and sustainable development initiatives in rural Southeast Asia.