Ornamental Plant Diversity and Traditional Uses in Home Gardens of Kham Toei Sub-District, Thai Charoen District, Yasothon Province, Northeastern Thailand

Abstract

Ornamental plants in rural household gardens provide esthetic, cultural, and practical value, yet their ethnobotanical and ethnopharmacological roles remain understudied. This study aimed to identify culturally significant ornamental species in Kham Toei Sub-district, Northeastern Thailand, document their multifunctional uses—including esthetic, ritual, edible, and medicinal roles—and examine how availability, perceived utility, and cultural context influence local valuations. Field surveys were conducted between June 2024 to May 2025 using purposive sampling to select 30 households, and semi-structured interviews were conducted with one primary informant per household. A total of 81 species from 36 families and 66 genera were recorded, dominated by herbaceous plants (53%), with introduced species (74%) exceeding natives (24%). Quantitative indices—Cultural Ornamental Significance Index (COSI), Fidelity Level (FL), and Informant Consensus Factor (FIC)—identified Aloe vera (L.) Burm.f., Cassia fistula L., Curcuma longa L., and Zingiber officinale Roscoe as culturally important species. High FL values, such as 80.00% for Jatropha podagrica Hook. (musculoskeletal use) and Tradescantia spathacea Sw. (gastrointestinal use), along with FIC of 0.83 for eye disorders, indicate strong community agreement on therapeutic applications. These findings demonstrate that ornamental plants support household healthcare, rituals, and ecological functions, reinforcing biocultural resilience and sustaining the integration of cultural, ecological, and medicinal values in community life.

1. Introduction

Ornamental plants serve multiple roles in human societies. Beyond their esthetic value, they express cultural identity, spiritual belief, and localized value systems [1]. In Thailand—similar to many Southeast Asian contexts—ornamental flora is embedded in social and ritual practices, where certain species symbolize auspiciousness, purity, or religious merit [2]. Their cultivation in home gardens, temples, communal areas, and ceremonial settings reflects the interaction between esthetics, traditional knowledge, and environmental adaptation. Understanding these sociocultural roles offers insight into biocultural heritage and the relationships between people and plants in rural landscapes [3].

Although ornamental plants are widely cultivated in Thailand, their cultural significance has received limited scholarly attention. Most ethnobotanical studies have focused on wild edibles, medicinal species, and the food–medicine continuum, contributing to knowledge on local health systems and ecological resilience [4]. In contrast, ornamental plants—despite their visibility—remain underdocumented. A few Thai studies provide useful examples: Ragsasilp et al. [5] recorded 34 Zingiberaceae ornamentals in Bueng Kan Province; Niamngon et al. [6] documented 40 species among the Isaan Lao community in Kalasin Province; and another study by Niamngon et al. [7] listed 55 ornamental species used by the Lao Isan group in Roi Et. However, no comprehensive ethnobotanical study has focused solely on ornamental species in Thailand.

Research outside Thailand further illustrates the importance of ornamentals. Studies in China show strong symbolic and ritual associations between ornamental plants and Buddhist figures [8], while research in Benin highlights the knowledge and socio-economic roles of ornamental plant producers [9]. Despite these contributions, most rely on conventional ethnobotanical indices such as Use Value (UV), Relative Frequency of Citation (RFC), and Cultural Food Significance Index (CFSI), which were originally developed to assess utilitarian plant functions in food and medicine [10]. These indices, developed for food and medicinal uses, do not adequately capture esthetic value, symbolic meanings, ritual use, or multifunctionality [11]. As a result, no standardized tools currently exist to quantify the cultural significance of ornamental plants.

Unlike food or medicinal species, whose value is tied to practical functions, ornamental plants are valued for esthetic, symbolic, and ritual reasons [12]. Traditional indices therefore fail to represent their cultural roles. To address this limitation, we introduce adapted tools including the Cultural Ornamental Significance Index (COSI), which integrates esthetic, symbolic, and ritual attributes into a single measure. These tools provide a more comprehensive framework for evaluating the cultural significance of ornamental species.

The research was conducted in Kham Toei Sub-district, Thai Charoen District, Yasothon Province, northeastern Thailand, a community notable for its integration of diverse religious practices, including Buddhism, Christianity, and local spirit worship. Ornamental plants are widely cultivated both for home decoration and for use in various rituals and ceremonies. The area also serves as a local production center for ornamental plants, with several nurseries and shops supplying the surrounding region. Selecting Kham Toei allows us to document the cultural significance of ornamental species in a setting where traditional horticultural practices, religious and ceremonial use, and local commerce intersect. Identifying culturally important species here can also provide practical guidance for future initiatives promoting ornamental plant cultivation and sustainable use.

Accordingly, this study seeks to address the following research questions:

(1)

Which ornamental plant species are perceived as culturally significant in Kham Toei Sub-district?

(2)

What functions—whether esthetic, ritual, edible, or health-related—are associated with these species?

(3)

How do availability, perceived utility, and cultural context shape local valuations of ornamental plants?

By applying both adapted and newly developed indices, this study fills a methodological gap in ethnobotanical research. The findings provide empirical data for Yasothon Province and offer a replicable model for evaluating the cultural significance of ornamental plants elsewhere. They also support community-based conservation, cultural heritage preservation, and sustainable horticultural practices that reinforce local knowledge systems.

2. Materials and Methods

2.1. Study Area

This study focuses on Kham Toei Sub-district, located in Thai Charoen District, Yasothon Province, in northeastern Thailand (Figure 1). The sub-district is known for its rich cultural heritage, agricultural traditions, and vibrant community life, making it an ideal location for investigating the ornamental cultural significance in local practices.

Kham Toei Sub-district covers approximately 71 square kilometers and includes 13 villages, with a population of around 5600 people. The area has a long history as an agrarian community, where rice cultivation serves as the primary economic activity. The fertile soil and abundant water resources, especially the Phong River that flows through the region, play a crucial role in supporting both agriculture and daily life. Most of the land in Kham Toei Sub-district is used for rice farming, while the rest is suitable for other crops and dryland agriculture. These natural and environmental factors have deeply influenced the local way of life, including customs and ornamental arts that are evident in everyday objects, religious ceremonies, and traditional festivals [14].

Religiously, Kham Toei is predominantly Theravāda Buddhist, which forms the foundation of most local traditions, rituals, and celebrations. The sub-district is also known for the Catholic Church of Saint Michael the Archangel in Ban Song Yae, a significant cultural and religious landmark [15]. This religious presence enriches the community’s cultural fabric and is reflected in their ornamental expressions. Both Buddhist and Christian symbols are incorporated into local crafts, architecture, and ceremonial items, showcasing intricate designs that represent the community’s spiritual beliefs and artistic identity.

The close connection between agriculture, natural resources, and religious practices in Kham Toei creates a unique cultural environment. The integration of these elements into the ornamental culture highlights how local people express their identity, values, and history through artistic forms. This dynamic interplay makes Kham Toei an ideal case study for exploring the significance of ornamental culture as a living tradition that preserves and conveys the cultural heritage of rural northeastern Thailand.

2.2. Field Survey and Data Collection

Field surveys were conducted between June 2024 to May 2025 in selected villages of Kham Toei Sub-district, Thai Charoen District, Yasothon Province. A purposive sampling approach [16] was employed to identify households with a high diversity of ornamental plants, focusing on those with cultural, esthetic, and ceremonial significance. The selection criteria included: (1) active cultivation of ornamental species; (2) clear maintenance and visible management practices; (3) representation of private (home garden) spaces; (4) continued cultural, medicinal, or ritual use of ornamental plants; and (5) presence of at least ten ornamental plant species within the household garden. In total, 30 households were surveyed.

In each household, one primary informant—the individual responsible for maintaining the home garden—was interviewed, meaning that “household” and “informant” represent the same sampling unit. A total of 30 households/informants were surveyed. Data saturation was reached during the interview process: after approximately the 26th household, no new plant species, uses, or cultural information emerged, and subsequent interviews produced only repeated data. This confirmed that the sample size was adequate, aligning with established guidelines indicating that ethnobotanical studies typically attain saturation with 20–40 knowledgeable informants when using purposive sampling [17,18,19].

Botanical identification was carried out through specimen collection, photographic documentation, and direct field observation. Scientific names were verified with the assistance of local botanists and cross-referenced using authoritative databases, Plants of the World Online (POWO) [20]. Voucher specimens were deposited at the Vascular Plant Herbarium, Mahasarakham University (VMSU), at Kantharawichai District, Maha Sarakham Province, Thailand, for archival purposes and future reference.

During the fieldwork, 30 informants—including household members, gardeners, cultural practitioners, and monks—participated in semi-structured interviews aimed at documenting traditional knowledge and the cultural significance of ornamental plants. The informant group consisted of 15 males and 15 females, aged between 20 and 65 years. No personal identifying information was collected during the interviews. To ensure confidentiality, the study did not record any details that could be used to identify individual participants, such as name, address, occupation, income level, or educational background. Only information related to ornamental plant diversity, uses, and cultural practices was documented. The interviews focused on: (1) local names; (2) ornamental value (esthetic, symbolic, or ritual); (3) occasions of use (festivals, rituals, decorations, or daily practices); and (4) management and cultivation practices.

Prior to each interview, the objectives of the study were clearly explained, and verbal Prior Informed Consent (PIC) was obtained from all participants. Respondents were informed of their rights, including voluntary participation and the ability to withdraw at any stage of the study. All interviews and specimen collections were conducted in accordance with the International Society of Ethnobiology (ISE) Code of Ethics [21] and the Nagoya Protocol on Access and Benefit Sharing [22].

Although the study did not involve sensitive personal data and formal institutional approval was not required, all procedures adhered to international ethnobotanical research standards to ensure respect, transparency, and reciprocity toward participating communities.

2.3. Data Analysis

2.3.1. Cultural Ornamental Significance Index (COSI)

In this study, the Cultural Ornamental Significance Index (COSI) was developed and applied to quantitatively assess the cultural importance of ornamental plant species within the community. The index is an adaptation of the Cultural Food Significance Index (CFSI) originally proposed by Pieroni (2001) [23], modified here to integrate the cultural, esthetic, and multifunctional roles of ornamental plants. By combining six key indicators, COSI provides a comprehensive measure of the perceived cultural value of each species. The COSI is calculated using the formula:

COSI = QI × OF × UR × UD × AR × OMRI × 10⁻²

(1)

The Quotation Index (QI) reflects the total number of spontaneous citations a species received from informants during interviews. This value highlights the cultural visibility of each ornamental plant, with higher scores indicating greater familiarity and recognition within the community. Species with fewer than two mentions were excluded from quantitative analysis.

The Occurrence Frequency (OF) represents how commonly a species occurs in the study area, based on direct field observations and informant reports. Values range from very common (4.0) to rare (1.0), with adjustments made for localization (e.g., ubiquity vs. highly localized presence). This measure captures the availability and spatial distribution of ornamental plants across households and communal areas.

The Usage Regularity (UR) captures the frequency with which species are maintained or interacted with. It considers practices such as watering, pruning, propagation, displaying, or gifting. Scores range from more than once per week (5.0) to no longer used in the past 30 years (0.5), providing insight into the continuity of plant–people interactions.

The Usage Diversity (UD) measures the number of distinct cultural or functional roles attributed to a plant species. Uses may include decoration, ritual purposes, shading, boundary marking, gifting, or fragrance. Each unique role is assigned a score, with higher values indicating multifunctionality and greater cultural integration.

The Esthetic Rating (AR) reflects local perceptions of beauty and visual appeal, based on informant evaluations. Ratings follow a five-point Likert scale [24], ranging from very beautiful (5.0) to not beautiful (1.0), and account for traits such as flower color, foliage, shape, and seasonal attractiveness.

Finally, the Ornamental-Medicinal Role Index (OMRI) captures the dual role of ornamental plants that also hold medicinal or health-related significance. Values range from not recognized (1.0) to very high (5.0), depending on whether the plant is used or believed to provide therapeutic or ritual health benefits in addition to its ornamental role.

A detailed classification system and corresponding values for each COSI component are presented in Table S1.

2.3.2. Plant Part Value (PPV)

The Plant Part Value (PPV) quantifies the relative importance of different plant parts in traditional practices. It indicates which parts—such as leaves, fruits, roots, stems, or flowers—are most frequently employed by the local community. According to the method of Gomez-Beloz [25], PPV is calculated as:

$$\mathrm{PPV}={\displaystyle \frac{\sum {\mathrm{RU}}_{\left(\mathrm{plant}\mathrm{part}\right)}}{\sum \mathrm{RU}}}\times 100$$

(2)

where RU_{(plant part)} refers to the number of use reports for a specific plant part, and ∑RU represents the total number of use reports for all plant parts. The PPV is expressed as a percentage, with higher values indicating more frequent use of a given plant part and emphasizing its relative importance in traditional practices.

2.3.3. Fidelity Level (%FL)

The Fidelity Level (FL) is used to measure how strongly a plant species is linked to a particular medicinal use within the community. It expresses the percentage of informants who consistently associate a species with the same therapeutic purpose, thereby indicating the reliability and cultural importance of its application. The FL is determined using the following formula [26]:

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

(3)

where I_p denotes the number of informants who reported the species for a specific ailment, and I_u refers to the total number of informants who mentioned the species for any medicinal use. A higher FL value reflects stronger consensus among informants and emphasizes the species recognized role in traditional healthcare practices.

2.3.4. Informant Consensus Factor (FIC)

The Informant Consensus Factor (FIC) evaluates the extent of agreement among informants concerning the use of plants for specific health-related categories. This index highlights ailments for which plant-based remedies are widely recognized and consistently applied within the community. FIC is calculated according to the following formula [27]:

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

(4)

where N_ur represents the total number of use reports for all species within a particular ailment category, and N_t denotes the number of species mentioned in that category. The FIC value ranges from 0 to 1, with higher values reflecting stronger consensus among informants and a more unified body of traditional knowledge regarding plant use for specific health conditions.

2.3.5. Cluster Analysis

To explore and illustrate the variation in Cultural Ornamental Significance Index (COSI) values among ornamental plant species recorded in Kham Toei Sub-district, the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) [28] was employed. The data matrix was analyzed using the UPGMA clustering algorithm, and the relationships among the recorded species were visualized as a heatmap generated with PAST4 software (version 4.15). This analytical approach facilitated a comparative evaluation of COSI patterns and ornamental plant diversity within the study area.

3. Results

3.1. Ornamental Plants Diversity, Origin and Life Forms in Kham Toei Sub-District

A total of 81 species of ornamental plants were recorded, belonging to 66 genera and 36 families (Figure 2 and Figure 3 and Table S2). The family Araceae was represented by the highest number of species (12 species), followed by Asparagaceae with 8 species, Apocynaceae with 7 species, Euphorbiaceae with 6 species, and Fabaceae with 5 species. Families such as Amaryllidaceae, Arecaceae, and Asteraceae each represented by three species. Six families, namely Acanthaceae, Commelinaceae, Crassulaceae, Polypodiaceae, Rubiaceae, and Zingiberaceae, were represented by 2 species each. The remaining 24 families contained only a single species.

Five main life forms were identified among the recorded species (Table S2). Herbs were the most dominant habit, comprising 53.00%, reflecting the prevalence of small, easily cultivated species commonly used for decorative and household purposes. Shrubs accounted for 23.00%, many of which are preferred for hedges and flowering displays. Climber species and trees each represent 10.00%, contributing to the vertical and structural diversity of the landscape. Ferns were the least represented group (4.00%), mainly occurring as shade-tolerant or epiphytic species. This distribution indicates a dominance of herbaceous forms, likely due to their adaptability, ease of propagation, and suitability for various ornamental settings.

The distribution status analysis showed that the majority of ornamental plant species were introduced (60 species; 74.00%), while 19 species (24%) were native to Thailand. Additionally, one species (1.00%) was classified as doubtful in origin, and one species (1.00%) could not be identified regarding its geographic origin. This indicates that most ornamental plants cultivated in the study area are exotic species that have been widely adopted for esthetic and landscape purposes.

3.2. Cultural Ornamental Significance Index (COSI) in Kham Toei Sub-District

A total of 81 ornamental plant species were evaluated for their cultural significance using the Cultural Ornamental Significance Index (COSI) (Table S3). The variation in COSI values reflects differences in recognition, multifunctionality, and integration into community life, highlighting how ornamental plants are embedded in both daily practices and ceremonial contexts.

Species with the highest cultural significance included Cassia fistula (COSI = 122.88), which was widely recognized and cultivated in nearly all surveyed home gardens. Heartwood from this species is used in ritual offerings, while flowers occasionally feature in traditional dishes, and it also holds moderate medicinal value for fever reduction and hemostasis. Zingiber officinale (COSI = 108.00) was primarily cultivated for its rhizome, used as a spice, herbal tea, and digestive tonic, while also serving an ornamental role due to its attractive foliage. Similarly, Curcuma longa (COSI = 96.00) provides rhizomes for culinary and ethnomedicinal use, particularly for gastrointestinal ailments, and is incorporated in ritual practices such as mixing with holy water for bathing Buddha images or elders.

Aloe vera (COSI = 72.00) is commonly displayed in home gardens, combining ornamental appeal with medicinal functionality, while Clitoria ternatea (COSI = 72.00) is valued for its flowers, which serve as a natural food colorant in desserts, rice, and beverages, and are recognized for eye health and musculoskeletal benefits, simultaneously enhancing garden esthetics.

Species with moderate cultural significance included Tamarindus indica (COSI = 52.80), whose fruits are used in beverages and culinary preparations, and whose young leaves and flowers are included in soups. Jasminum sambac (COSI = 46.08) is valued for its fragrant flowers in ritual arrangements, teas, and desserts, with leaves and flowers occasionally used topically for skin ailments.

In contrast, species with low cultural significance, such as Dieffenbachia longispatha (COSI = 11.52), Caladium bicolor (COSI = 4.80), and Ixora chinensis (COSI = 7.56), were primarily maintained for decorative purposes, with limited multifunctional or medicinal roles. This demonstrates that cultural significance depends not only on visual appeal but also on practical utility and integration into social practices.

Overall, the COSI analysis illustrates that species with high cultural significance are actively woven into multiple aspects of community life, encompassing rituals, food preparation, medicinal use, and esthetic enjoyment. These multifunctional plants embody a fusion of practical, symbolic, and social values, serving as cultural anchors within households and communal spaces. Conversely, species with lower COSI scores, despite their ornamental presence, exhibit minimal engagement in broader cultural practices, reflecting selective cultural valuation within the community.

The heatmap analysis (Figure 4) clearly illustrated the variation in Cultural Ornamental Significance Index (COSI) values. Clusters conceptually represent groups of species with similar levels of cultural and functional importance. For instance, Cassia fistula, Curcuma longa, and Zingiber officinale form a central cluster, reflecting consistently high importance across multiple dimensions—ritual use, household decoration, and multifunctionality—confirming their central role in local cultural traditions. Peripheral clusters, such as those containing Bougainvillea glabra, Euphorbia tirucalli, and Nephrolepis exaltata, represent species with more specialized or limited ornamental roles, often valued primarily for esthetics rather than multifunctional or ritual significance.

Several moderately high-ranking species, including Phyllanthus acidus, Tabernaemontana divaricata, and, Tecoma stans occupy intermediate positions, indicating flexibility and multifunctionality across diverse cultural contexts, from daily household use to ritual applications. Species with lower overall COSI scores typically show limited association with symbolic or ritual functions, despite their presence in the community. Some species, such as Euphorbia ritchiei, Nelumbo nucifera, and Polyscias fruticosa, demonstrate moderate yet well-distributed values across COSI dimensions, highlighting a balanced contribution to both domestic and ceremonial practices.

Taken together, the heatmap provides a visual representation of the relative cultural embedding and multifunctionality of ornamental species, enabling identification of both core and peripheral species in the community’s biocultural landscape. This conceptual clustering highlights which species are central to cultural practices and which occupy more specialized or context-dependent roles, offering guidance for conservation and ethnobotanical research.

3.3. Other Utilization of Ornamental Plants in Kham Toei Sub-District

Ornamental plants in Kham Toei Sub-district serve multiple roles beyond decoration, encompassing food, ritual, and medicinal applications. Across these uses, residents selectively utilize flowers, leaves, fruits, rhizomes, and whole plants according to cultural norms, household needs, and symbolic meanings, highlighting the multifunctional significance of ornamental species in local life.

Fifteen species from 11 families are traditionally incorporated into local cuisine. Flowers are the most commonly consumed part, used in desserts, teas, curries, and as natural food colorants, while leaves and fruits supplement soups, beverages, and cooked dishes. Species such as Clitoria ternatea, Jasminum sambac, and Rosa chinensis are valued for their fragrance and visual appeal in addition to their culinary uses. Rhizomatous plants like Cocos nucifera and Nelumbo nucifera illustrate the intersection of ornamentation and subsistence, providing versatile edible parts that support daily meals (

Table 1. Ornamental plant species are used as food, with their edible parts and methods of utilization.

No.	Scientific Name	Used Part	Method of Use
1.	Asystasia gangetica (L.) T.Anderson	Leaf, young shoot	Cooked as a leafy vegetable, stir-fried or boiled
2.	Cassia fistula L.	Flower	Flowers cooked in curries
3.	Clitoria ternatea L.	Flower	Used as a natural food colorant in rice, desserts, and drinks; eaten fresh as beverage
4.	Cocos nucifera L.	Endosperm (coconut flesh), water, inflorescence sap	Eaten fresh, grated for cooking, coconut water as beverage, sap for sugar or drink
5.	Combretum indicum (L.) DeFilipps	Flower	Consumed fresh or used to flavor beverages
6.	Ixora chinensis Lam.	Flower	Used fresh in traditional desserts or eaten raw
7.	Jasminum sambac (L.) Aiton	Flower	Used to flavored tea, desserts, and beverages
8.	Morinda citrifolia L.	Fruit, leaf	Ripe fruits eaten fresh or processed as juice; young leaves cooked as vegetable
9.	Nelumbo nucifera Gaertn.	Rhizome, seed, young leaf	Rhizomes boiled or stir-fried, seeds eaten fresh or roasted, young leaves used for wrapping food
10.	Phyllanthus acidus (L.) Skeels	Fruit, leaf	Fruits eaten fresh, pickled, or in preserves; leaves sometimes used as vegetable
11.	Rosa chinensis Jacq.	Flower	Petals used in teas, desserts, or syrups
12.	Sesbania javanica Miq.	Flower	Flowers eaten fresh in salads or cooked
13.	Tamarindus indica L.	Fruit, young leaf, flower	Pulp used in beverages, sauces, and curries; young leaves and flowers used in soups
14.	Tecoma stans (L.) Juss. ex Kunth	Flower	Occasionally consumed fresh or used as garnish in salads
15.	Zingiber officinale Roscoe	Rhizome	Used as spice, condiment, tea, and in curries

).

Many of these food plants also feature in ritual practices. Twenty-one species are employed in ceremonial contexts, where whole-plant offerings symbolize prosperity and spiritual protection, and fragrant flowers enhance ceremonial arrangements (bai sri). Species such as Curcuma longa and Jasminum sambac are incorporated into purification rituals, demonstrating the symbolic and cultural integration of ornamental plants. This overlap between edible and ritual species illustrates how multifunctional plants reinforce both household and community traditions (

Table 2. Ornamental plant species used in ritual activities, with their edible parts and methods of utilization.

No.	Scientific Name	Used Part	Method of Use
1.	Alocasia cucullata (Lour.) G.Don	Whole plant	Believed in attracting wealth, fortune, and prosperity.
2.	Alocasia sanderiana W.Bull	Whole plant	Believed in attracting wealth, fortune, and prosperity.
3.	Calotropis gigantea (L.) W.T.Aiton	Flower	Used in traditional ceremonial arrangements (bai sri) for worship and rituals such as weddings, ordinations, and spirit-calling ceremonies.
4.	Cassia fistula L.	Leaf, shoot	Leaves are used in major ceremonies such as the city pillar ritual; heartwood is part of ceremonial betel sets used in the worship of deities.
5.	Chlorophytum laxum R.Br.	Whole plant	Believed in attracting wealth, fortune, and prosperity.
6.	Cocos nucifera L.	Fruit	Used in religious and spiritual ceremonies.
7.	Crinum asiaticum L.	Leaf	Mixed into holy water to dispel evil spirits.
8.	Crinum latifolium L.	Whole plant	Believed in attracting wealth, fortune, and prosperity.
9.	Crinum sp.	Whole plant	Believed in attracting wealth, fortune, and prosperity.
10.	Curcuma longa L.	Rhizome	Mixed into holy water for bathing Buddha images or elders during rituals.
11.	Dieffenbachia longispatha Engl. & K.Krause	Whole plant	Believed in attracting wealth, fortune, and prosperity.
12.	Dracaena braunii Engl.	Whole plant	Believed in attracting wealth, fortune, and prosperity.
13.	Dracaena fragrans (L.) Ker Gawl.	Whole plant	Believed in attracting wealth, fortune, and prosperity.
14.	Dracaena stuckyi (God.-Leb.) Byng & Christenh.	Whole plant	Believed in attracting wealth, fortune, and prosperity.
15.	Euphorbia bracteata Jacq.	Whole plant	Believed in attracting wealth, fortune, and prosperity.
16.	Ixora chinensis Lam.	Flower	Used in traditional ceremonial arrangements (bai sri) for worship and rituals such as weddings, ordinations, and spirit-calling ceremonies.
17.	Jasminum sambac (L.) Aiton	Flower	Mixed into holy water for bathing Buddha images or elders during rituals.
18.	Plumeria obtusa L.	Flower	Used in traditional ceremonial arrangements (bai sri) for worship and rituals such as weddings, ordinations, and spirit-calling ceremonies.
19.	Syngonium podophyllum Schott	Whole plant	Believed in attracting wealth, fortune, and prosperity.
20.	Tabernaemontana divaricata (L.) R.Br. ex Roem. & Schult.	Flower	Used in traditional ceremonial arrangements (bai sri) for worship and rituals such as weddings, ordinations, and spirit-calling ceremonies.
21.	Zamioculcas zamiifolia (G.Lodd.) Engl.	Whole plant	Believed in attracting wealth, fortune, and prosperity.

).

In addition to esthetic, culinary, and ritual roles, fourteen species are recognized for their medicinal potential. Flowers and leaves are most frequently utilized, reflecting ease of harvest and cultural familiarity in traditional preparations. Species including Curcuma longa, Phyllanthus acidus, Tradescantia spathacea, and Zingiber officinale exemplify this dual functionality, supporting household health practices while enhancing garden beauty. Such multifunctionality underscores that ornamental plants are not only decorative but also integral to daily life, ritual activities, and the broader cultural identity of the community. The relative frequency of plant parts used for medicinal purposes mirrors patterns observed for food and ritual applications, with inflorescences, leaves, fruits, and rhizomes being the most commonly cited (Figure 5).

Regarding the condition of plant materials, fresh specimens were predominantly employed (71.00%), whereas dried materials accounted for 29.00%, reflecting both immediate use and preservation practices for future applications. Among routes of administration, oral use was most common (77.00%), emphasizing treatments for internal ailments such as digestive, febrile, and cardiovascular disorders, while dermal application (23.00%) was primarily associated with skin, wound, and inflammatory conditions (

Table 3. Ethnomedicinal uses of plant species recorded in the study area, including scientific name, Fidelity Level (FL), used parts, condition of plants used (CoP), preparation, medicinal properties, Route of Administration (RoA), and Therapeutic categories.

No.	Scientific Name	FL	Used Parts	CoP	Preparation	Medicinal Properties	RoA	Therapeutic Categories
1.	Aloe vera (L.) Burm.f.	60.00	Leaf	Fresh	The leaf is peeled and carefully cleansed to eliminate the mucilaginous layer, after which the transparent gel is directly applied to treat wounds	Traditionally used to promote wound healing and to treat abscesses and inflammatory conditions	Dermal	Skin System
		40.00	Leaf	Fresh	Fresh leaves are peeled, the mucilage removed, and the clear gel blended to prepare a refreshing traditional beverage	Traditionally employed to relieve bruises and to facilitate wound healing	Oral	Musculoskeletal and Joint Diseases
2.	Areca catechu L.	66.67	Leaf	Fresh	The plant is boiled with water, and the decoction is used for bathing	The plant is traditionally used to reduce body heat, alleviate fever, and relieve symptoms of the common cold	Dermal	Infection, Parasite and Immune System
		33.33	Seed	Dry	The plant parts are sun-dried, ground into powder, and infused in hot water to prepare a traditional herbal infusion for oral consumption	Traditionally used as an anthelmintic remedy to expel intestinal parasites such as roundworms, tapeworms, and liver flukes	Dermal	Infection, Parasite and Immune System
3.	Calotropis gigantea (L.) W.T.Aiton	57.14	Inflorescence	Fresh	The plant is boiled in water, and the resulting decoction is filtered to obtain the liquid, which is then used	Traditionally used as an antipyretic remedy to reduce fever	Oral	Infection, Parasite and Immune System
		42.86	Shoot	Fresh	The plant is boiled in water, and the resulting decoction is filtered to obtain the liquid, which is then used	Traditionally used as an expectorant to relieve phlegm and respiratory congestion	Oral	Gastrointestinal
4.	Cassia fistula L.	50.00	Inflorescence	Fresh	The plant is boiled in water, and the resulting decoction is filtered to obtain the liquid, which is then used	Traditionally used as an antipyretic remedy to reduce fever	Oral	Infection, Parasite and Immune system
		37.50	Inflorescence	Fresh	The plant is boiled in water, and the resulting decoction is filtered to obtain the liquid, which is then used	Traditionally used to stop bleeding and treat hemorrhagic conditions	Oral	Obstetrics, Gynecology and Urinary Disorders
		12.50	Root	Fresh	The plant is boiled in water, and the resulting decoction is filtered to obtain the liquid, which is then used	Traditionally used to treat cardiovascular disorders	Oral	Cardiovascular System
5.	Clitoria ternatea L.	37.50	Inflorescence	Fresh	The flower petals are crushed to obtain the juice, which is then ingested as a traditional beverage	Traditionally used to strengthen vision and alleviate symptoms such as blurred or watery eyes	Oral	Eye Disorders
		37.50	Inflorescence	Fresh	Traditionally consumed fresh/raw.	Traditionally used to prevent and alleviate numbness or tingling sensations in the fingers and toes.	Oral	Musculoskeletal and Joint Diseases
		25.00	Inflorescence	Fresh	Traditionally incorporated as an ingredient in cosmetic and personal care products, including hair conditioners and shampoos	Traditionally used to stimulate hair growth and enhance hair pigmentation	Dermal	Skin System
6.	Combretum indicum (L.) DeFilipps	57.14	Seed	Dry	The plant is boiled in water, and the resulting decoction is filtered to obtain the liquid, which is then used	Traditionally used as an anthelmintic to eliminate roundworms and intestinal worms	Oral	Infection, Parasite and Immune System
		42.86	Leaf	Fresh	The plant material is crushed and applied topically as a poultice on the affected skin area	Traditionally used to promote wound healing and to treat abscesses and inflammatory conditions	Dermal	Skin System
7.	Curcuma longa L.	50.00	Rhizome	Dry	Dried, powdered, mixed with honey, and pressed into pills	Traditionally used to relieve bloating, flatulence, abdominal discomfort, and indigestion	Oral	Gastrointestinal
		50.00	Rhizome	Dry	Dried, powdered, mixed with honey, and pressed into pills	Traditionally used to treat dyspepsia (indigestion), including symptoms such as bloating, nausea, and abdominal discomfort	Oral	Gastrointestinal
8.	Jasminum sambac (L.) Aiton	37.50	Inflorescence	Dry	The plant is sun-dried, boiled in water, and the filtered liquid is consumed as a drink or prepared as a herbal tea	Traditionally used to nourish the heart and maintain cardiovascular vitality	Oral	Cardiovascular System
		37.50	Root	Fresh	The plant material is pounded and combined with water, then consumed orally	Traditionally used to alleviate skin itching and to promote healing of chronic wounds	Dermal	Skin System
		25.00	Leaf	Fresh	The plant material is finely pounded and combined with coconut oil, then gently heated before being applied topically to the affected skin area	Traditionally used to promote wound healing and to treat abscesses and inflammatory conditions	Dermal	Skin System
9.	Jatropha podagrica Hook.	80.00	Shoot	Dry	The plant is sun-dried, boiled in water, and the filtered liquid is consumed as a drink	Traditionally used to enhance physical strength and overall vitality	Oral	Musculoskeletal and Joint Diseases
		20.00	Latex	Fresh	Wounds and abscesses are first cleaned thoroughly, and the plant extract or liquid is then applied directly to the affected area	Traditionally used to promote the healing of wounds—fresh, suppurating, and ulcerated—and to treat abscesses	Dermal	Skin System
10.	Morinda citrifolia L.	57.14	Leaf	Dry	The plant is sun-dried, boiled in water, and the filtered liquid is consumed as a drink	Traditionally used to alleviate pain and discomfort in the wrists and ankles	Oral	Musculoskeletal and Joint Diseases
		28.57	Leaf	Dry	The plant is sun-dried, boiled in water, and the filtered liquid is consumed as a drink	Traditionally used to alleviate diarrhea, reduce coughing, facilitate phlegm expulsion, and relieve abdominal bloating and discomfort	Oral	Gastrointestinal
		14.29	Inflorescence	Dry	The plant is sun-dried, boiled in water, and the filtered liquid is consumed as a drink or prepared as a herbal tea	Traditionally used to maintain heart health and prevent cardiovascular disorders	Oral	Cardiovascular System
11.	Phyllanthus acidus (L.) Skeels	71.43	Fruit	Fresh	Traditionally consumed fresh/raw.	Traditionally used to alleviate fever and treat cough	Oral	Infection, Parasite and Immune System
		28.57	Fruit	Fresh	Traditionally consumed fresh/raw.	Traditionally used to promote bowel movements as a natural laxative	Oral	Gastrointestinal
12.	Tamarindus indica L.	40.00	Fruit	Fresh	Traditionally consumed fresh/raw.	Traditionally used to alleviate eye pain and discomfort	Oral	Eye Disorders
		30.00	Fruit	Fresh	The seed coat is soaked in water, combined with sugar to impart a sweet taste, and the resulting liquid is consumed as a beverage	Traditionally used to alleviate fever and treat cough	Oral	Infection, Parasite and Immune System
		30.00	Seed	Fresh	The seeds are roasted, the shells removed, and the seed kernels are soaked in salt water until soft before being eaten	Traditionally used to alleviate diarrhea and vomiting	Oral	Gastrointestinal
13.	Tradescantia spathacea Sw.	80.00	Inflorescence	Dry	The plant is sun-dried, boiled in water, and the filtered liquid is consumed as a drink	Traditionally used to alleviate cough, sore throat, mouth ulcers, excessive thirst, and vomiting of blood	Oral	Gastrointestinal
		20.00	Leaf	Fresh	The plant is boiled in water, then combined with honey, lemon juice, and salt, and the resulting decoction is consumed orally	Traditionally used to alleviate symptoms of acid reflux	Oral	Gastrointestinal
14.	Zingiber officinale Roscoe	35.71	Rhizome	Fresh	Traditionally consumed fresh/raw.	Traditionally employed as a restorative tonic to stimulate digestive fire and promote balance among bodily elements	Oral	Gastrointestinal
		28.57	Fruit	Fresh	The plant is boiled in water, and the resulting decoction is filtered to obtain the liquid, which is then used	Traditionally administered to alleviate dryness of the throat and soothe sore throat	Oral	Infection, Parasite and Immune System
		21.43	Root	Fresh	The plant is boiled in water, and the resulting decoction is filtered to obtain the liquid, which is then used	Traditionally used to reduce phlegm and facilitate the clearing of respiratory passages	Oral	Infection, Parasite and Immune System
		14.29	Inflorescence	Fresh	The plant is boiled in water, and the resulting decoction is filtered to obtain the liquid, which is then used	Traditionally used to alleviate urinary problems or act as a diuretic	Oral	Obstetrics, Gynecology and Urinary Disorders

).

3.4. Fidelity Level (%FL) of Ornamental Plants in Kham Toei Sub-District

The Fidelity Level (FL) analysis provides insight into the degree of cultural consensus regarding the medicinal uses of ornamental plants in Kham Toei Sub-district (Table 3). FL reflects the proportion of informants who mention a species for its primary therapeutic purpose, indicating its cultural importance and perceived efficacy.

Several species exhibited high FL values, suggesting strong agreement among informants. For instance, Jatropha podagrica and Tradescantia spathacea were widely recognized for enhancing vitality and alleviating gastrointestinal ailments, respectively. Phyllanthus acidus was commonly cited for fever reduction and cough relief. Other notable species with high consensus included Areca catechu (used in bathing for fever alleviation) and Aloe vera (applied topically to treat wounds and inflammation).

Moderate FL values were observed for species with multifunctional roles, such as Cassia fistula and Curcuma longa, reflecting their use for multiple health conditions. Species with lower FL values generally had diverse medicinal applications, with informant citations divided among several uses. For example, Clitoria ternatea was used for eye health, musculoskeletal ailments, and hair stimulation, showing a versatile yet less consensus-driven use.

Overall, the FL analysis highlights the ornamental species that are most culturally validated for specific therapeutic purposes, while also illustrating the multifunctionality and complexity of local ethnomedicinal knowledge.

A detailed summary of species, used parts, preparation methods, therapeutic uses, and corresponding FL values is presented in Table 3.

3.5. Informant Consensus Factor (FIC) of Ornamental Plants in Kham Toei Sub-District

The Informant Consensus Factor (FIC) values were calculated to evaluate the degree of agreement among informants regarding the medicinal applications of ornamental plants in Kham Toei Sub-district. The FIC values ranged from 0.50 to 0.83, indicating varying levels of consensus across therapeutic categories (

Table 4. Informant consensus factor (FIC) of medicinal applications of ornamental plants in Kham Toei Sub-district, Thai Charoen District, Yasothon Province, Thailand.

Therapeutic Categories	Number of Use Report (Nur)	Number of Taxa (Nt)	FIC
Eye Disorders	7	2	0.83
Infection, Parasite and Immune System	33	7	0.81
Gastrointestinal	26	7	0.76
Musculoskeletal and Joint Diseases	13	4	0.75
Obstetrics, Gynecology and Urinary Disorders	5	2	0.75
Skin System	14	5	0.69
Cardiovascular System	5	3	0.50

).

The highest consensus was observed for Eye Disorders, primarily associated with Clitoria ternatea and Tamarindus indica, highlighting a strong agreement among informants on species used to improve vision and alleviate eye irritation. The Infection, Parasite, and Immune System category also showed high consensus, with species such as Combretum indicum, Phyllanthus acidus, and Zingiber officinale widely recognized for treating fever, cough, and parasitic infections.

Moderately high consensus was recorded for Gastrointestinal ailments, where Curcuma longa, Morinda citrifolia, and Tradescantia spathacea were commonly cited for digestive discomfort, acid reflux, and diarrhea. Similar agreement was observed for Musculoskeletal and Joint Diseases and Obstetrics, Gynecology, and Urinary Disorders, reflecting shared knowledge on plants used to relieve muscle pain, numbness, and urinary conditions.

Lower consensus was noted for the Skin System and Cardiovascular System, suggesting more diverse plant use or less common knowledge among informants. Overall, the F_ic analysis indicates strong cultural coherence in the medicinal applications of ornamental plants, particularly for eye health, infection-related, and gastrointestinal treatments.

4. Discussion

4.1. Diversity and Structural Composition of Ornamental Plants

The ornamental plant diversity documented in Kham Toei Sub-district reflects a rich assemblage shaped by both cultural preferences and environmental adaptability. The 81 species recorded, representing 66 genera and 36 families, indicate substantial diversity within local home gardens. While comparable numbers have been reported—78 species in Benin [9], 60 species in China [8], and 132 taxa in Northeastern Mexico [29]—our study goes beyond mere species counts. Unlike the Benin study, which focused on producers’ knowledge, and the China study, which emphasized temple-based symbolic use, our research captures household-level cultivation and multifunctional use in a multicultural religious context, where Buddhism, Christianity, and local spirit worship coexist. By applying COSI along with FL and FIC, we identify species that are not only visually prominent but also culturally and medicinally significant, providing insights into informant consensus, daily utility, and ritual integration. This quantitative approach highlights species’ multifunctionality and cultural embeddedness, offering practical guidance for sustainable use and conservation of ornamental plants at the community level.

The most representative families—Araceae, Asparagaceae, Apocynaceae, Euphorbiaceae, and Fabaceae—include species valued for their attractive foliage, showy inflorescences, and tolerance to tropical conditions, making them highly suitable for small-scale gardens [30,31,32].

Herbaceous plants form the core of ornamental gardening in Kham Toei Sub-district, reflecting local preferences for species that are easy to maintain, fast-growing, and adaptable to limited household space. Shrubs, climbers, trees, and ferns complement this foundation by adding structural layering and visual diversity, suggesting that households intentionally combine growth forms to create multifunctional garden spaces. Rather than serving purely decorative purposes, this structural composition supports broader ecological functions. As noted by Wright and Francia [33], heterogeneous vegetation can buffer microclimatic extremes by enhancing shade, moderating temperature, and increasing relative humidity. These patterns indicate that home gardens in Kham Toei operate as informal nature-based solutions, contributing to local cooling, supporting pollinators, and enhancing household environmental resilience [34]. Such practices highlight a culturally embedded understanding of how ornamental plants provide both esthetic and functional benefits.

Introduced species (75.00%) greatly outnumbered native ones (23.75%) in Kham Toei Sub-district, reflecting the influence of horticultural trade and global plant circulation. Similar trends have been reported in temperate and tropical regions, where exotic ornamentals dominate home gardens due to their esthetic appeal, extended flowering periods, and adaptability to changing environmental conditions [35]. While these species enhance decorative value and resilience to climate variability [1], the lower representation of native plants underscores potential gaps in conserving local flora [36]. Promoting native ornamentals could support biodiversity, preserve ethnobotanical knowledge, and strengthen ecosystem services by enhancing microclimate regulation and habitat provision [37,38]. Moreover, careful selection of species—considering both adaptive traits and ecological risks—can optimize the benefits of ornamental plantings while minimizing the introduction of potentially invasive taxa in the face of climate change [39].

Beyond ecological considerations, socio-economic and cultural factors strongly influence ornamental plant preferences. Exotic species are often valued for their vibrant colors, prolonged flowering, and novelty, which enhance household esthetics and social prestige. They are frequently chosen for ceremonial displays, gifting, or community rituals, reflecting their symbolic and cultural significance [40]. In contrast, native species, despite their ecological and traditional importance, may be perceived as less ornamental or less commercially available, which contributes to their lower prevalence in local gardens [41]. Recognizing these socio-cultural drivers is essential for designing interventions that promote native species without compromising local esthetic or cultural priorities [42].

4.2. Cultural Significance of Ornamental Plants

The Cultural Ornamental Significance Index (COSI) analysis in Kham Toei Sub-district highlights the central role of a subset of ornamental species in local cultural practices. Cassia fistula emerged as the most culturally significant species, reflecting its widespread recognition, frequent presence in home gardens, multifunctional use, and combined ornamental-medicinal value [43]. High-ranking species such as Aloe vera, Clitoria ternatea, Curcuma longa, and Zingiber officinale similarly demonstrate dual roles, serving both decorative and practical purposes, including culinary and medicinal functions [44,45].

In contrast, species with lower COSI values, such as Dieffenbachia longispatha, Caladium bicolor, and Ixora chinensis, were maintained primarily for visual appeal, indicating that esthetic value alone does not guarantee broad cultural integration [46,47]. The heatmap analysis further revealed clustering of species according to their multifunctionality and ritual importance, with Cassia fistula, Curcuma longa, and Zingiber officinale forming a core group central to ceremonies, household decoration, and communal rituals [2,48]. Peripheral species, including Bougainvillea glabra and Nephrolepis exaltata, had more specialized ornamental roles, suggesting limited cultural penetration.

Several moderately ranked species, such as Tabernaemontana divaricata, Tecoma stans, and Phyllanthus acidus, displayed versatility across multiple cultural contexts, reinforcing the importance of multifunctionality in achieving higher overall cultural significance. Studies have highlighted the therapeutic or utilitarian roles of these species, illustrating how cultural integration depends not only on visual appeal but also on functional utility, ritual relevance, and daily household engagement [49,50]. Methodologically, COSI advances ethnobotany by combining recognition, availability, maintenance, multifunctionality, esthetic perception, and ornamental-medicinal roles into a composite measure, surpassing traditional indices focused solely on medicinal importance or citation frequency.

4.3. Traditional and Cultural Roles of Ornamental Plants

The present study reveals that ornamental plants in Kham Toei Sub-district play a crucial role in sustaining local livelihoods, traditional practices, and cultural identity. Beyond their esthetic value, these species are deeply embedded in food traditions, health care, and spiritual belief systems, reflecting the multifunctional nature of home garden biodiversity in Northeastern Thailand. Such multifunctionality highlights the adaptive strategies of rural communities that integrate ecological knowledge with cultural continuity, echoing similar observations across tropical regions where ornamental and utilitarian plants coexist within household spaces [49,51].

The use of ornamental species as food and medicine illustrates a convergence between beauty and utility. This pattern aligns with findings from ethnobotanical studies in Asia, which emphasize that household gardens often serve as both nutritional and therapeutic reserves [52,53,54]. In Kham Toei, floral parts such as those of Clitoria ternatea and Ixora chinensis exemplify this relationship, providing visual appeal while serving dietary or medicinal purposes. These practices reflect a traditional ecological knowledge system that maximizes plant diversity to support food security, well-being, and esthetic pleasure within limited land spaces [1,55].

Ritual and religious use of ornamentals further underscores their cultural significance. Plants such as Jasminum sambac, Tabernaemontana divaricata, and Plumeria obtusa retain symbolic importance in Buddhist and animistic ceremonies, reinforcing values of purity, reverence, and prosperity [56]. Their persistent use demonstrates resilience of intangible cultural heritage amid social and environmental change. These findings are consistent with previous studies in Thailand and neighboring countries, where ornamental species serve as mediators between humans and the spiritual realm [57].

Ornamental plants in Kham Toei Sub-district serve important medicinal roles, highlighting their ethnopharmacological relevance within household landscapes. Species such as Aloe vera, Curcuma longa, and Zingiber officinale are readily accessible for treating common ailments, reflecting the integration of horticulture and traditional healthcare practices [58]. Inflorescences and leaves are the most frequently used plant parts, often prepared fresh for oral administration or topical applications, consistent with ethnomedicinal traditions in Asia [59,60]. The coexistence of esthetic and medicinal functions demonstrates how ornamental cultivation contributes to the resilience of local knowledge systems, ensuring that plant resources are both visually appreciated and functionally valuable [61]. This multifunctionality reinforces the importance of preserving ornamental species that possess therapeutic potential, offering insights for conservation strategies that align cultural, medicinal, and biodiversity priorities.

Overall, the findings underscore the role of ornamental plants as key components of biocultural resilience—maintaining both ecological functionality and cultural expression. Home gardens in Kham Toei Sub-district thus act as microcosms of sustainable living, conserving traditional knowledge while adapting to modern influences. Recognizing and promoting these multifunctional species can inform sustainable horticultural and conservation strategies, ensuring that cultural and biological diversity continue to reinforce each other in rural Thai communities.

4.4. Medicinal Significance of Ornamental Plants

The analysis of Fidelity Level (FL) and Informant Consensus Factor (FIC) highlights the ethnopharmacological importance of ornamental plants in Kham Toei Sub-district. High FL values observed in species such as Jatropha podagrica (80%), Tradescantia spathacea (80%), and Phyllanthus acidus (71.43%) indicate strong agreement among local informants regarding their primary therapeutic applications. These results reflect a well-established cultural consensus on the efficacy of certain species for specific ailments, demonstrating that household cultivation of ornamentals provides a reliable and accessible source of medicinal resources [62].

Moderate FL values in species like Cassia fistula and Curcuma longa suggest multifunctional use, where a single species serves multiple therapeutic purposes, leading to slightly lower consensus for any one application. Conversely, species with lower FLs, such as Clitoria ternatea, reveal a diversity of recognized uses, illustrating complex traditional knowledge systems in which medicinal roles are context dependent [63].

Informant Consensus Factor (FIC) analysis further corroborates these findings, with the highest agreement observed in Eye Disorders (0.83) and Infection, Parasite, and Immune System categories (0.81). These high FIC values underscore the cultural reliability of specific species—Clitoria ternatea, Phyllanthus acidus, Tamarindus indica and Zingiber officinale—for treating common health issues. Moderate consensus in gastrointestinal and musculoskeletal categories reflects both the prevalence of these ailments and the availability of multiple effective ornamental species for their management. Lower F_ic values in skin and cardiovascular treatments suggest either a broader diversity of species used or more individualized knowledge, indicating potential areas for further ethnopharmacological investigation [64].

Collectively, FL and FIC analyses emphasize that ornamental plants in Kham Toei serve not only decorative purposes but also act as culturally validated medicinal resources. The alignment of high FL and FIC values identifies priority species for conservation, further pharmacological study, and integration into community-based healthcare strategies, reinforcing the multifunctional value of ornamental plants within traditional household landscapes.

4.5. Novelty of the Study

This study provides a comprehensive assessment of ornamental plant diversity, cultural significance, and ethnomedicinal use within Kham Toei Sub-district, Northeastern Thailand, highlighting several novel contributions. While previous research often focuses either on ornamental diversity or on medicinal use, our study integrates both aspects, emphasizing the multifunctional roles of species. By applying quantitative indices such as the Cultural Ornamental Significance Index (COSI), Fidelity Level (FL), and Informant Consensus Factor (FIC), we link esthetic, ritual, edible, and medicinal uses to household and community practices.

The COSI framework is particularly innovative because it combines multiple dimensions—recognition (Quotation Index), availability (Occurrence Frequency), maintenance (Usage Regularity), multifunctionality (Usage Diversity), esthetic perception (Esthetic Rating), and medicinal or ritual roles (Ornamental-Medicinal Role Index)—into a single measure of cultural significance. Unlike traditional indices that focus solely on medicinal importance or citation frequency, COSI captures the holistic value of ornamental plants, identifying species that are not only visually prominent but also deeply embedded in daily life, rituals, and community knowledge systems.

This study highlights the multifunctionality of ornamental plants. Species such as Cassia fistula, Phyllanthus acidus, and Tabernaemontana divaricata simultaneously fulfill esthetic, ritual, nutritional, and medicinal roles. In comparison, the study in Benin [9] documented 78 ornamental species in household gardens, focusing on esthetic, therapeutic, psycho-magical, cosmetic, and food-related uses, but primarily examined socio-demographic predictors of knowledge rather than multifunctionality. Similarly, the study in China [8] recorded 60 species associated with Buddhist figures, emphasizing symbolic associations and temple-based propagation rather than household-level practices. By quantitatively assessing multifunctional roles through indices such as COSI, FL, and FIC, the present study demonstrates how ornamental plants are integrated into daily household life, revealing their combined esthetic, medicinal, ritual, and nutritional functions—a dimension not captured in the previous studies.

Additionally, documentation of structural composition and the balance of native versus introduced species provides insight into ecological roles, including microclimate regulation and habitat support for pollinators. Linking these ecological findings to cultural and medicinal significance strengthens the practical relevance of the study, offering guidance for conservation, sustainable horticultural management, and community-based healthcare strategies.

Overall, the combination of quantitative ethnobotanical indices with detailed field documentation offers a comprehensive perspective on how ornamental plants contribute to biocultural heritage, multifunctionality, and local well-being. This integrative approach serves as a reference for similar studies in other tropical and subtropical communities.

5. Conclusions

This study documents the diversity, cultural significance, and medicinal use of ornamental plants in Kham Toei Sub-district, Northeastern Thailand, highlighting their multifunctional roles within household gardens. A total of 81 species, spanning 66 genera and 36 families, were recorded, with herbaceous species dominating the assemblage and introduced taxa outnumbering native plants. By applying quantitative indices such as COSI, FL, and FIC, we identified a subset of species—including Cassia fistula, Phyllanthus acidus, and Tabernaemontana divaricata—that are highly valued for their esthetic, ritual, nutritional, and medicinal functions.

The findings emphasize that ornamental plants are not merely decorative; they contribute to local livelihoods, preserve traditional knowledge, and provide culturally validated medicinal resources. High Fidelity Level (FL) values—such as 80.00% for Tradescantia spathacea (used for gastrointestinal disorders) and 80.00% for Jatropha podagrica (used for musculoskeletal and joint ailments)—along with a high Informant Consensus Factor (FIC) of 0.83 for eye disorders, indicate strong community agreement on specific therapeutic uses. Meanwhile, COSI highlights species that are culturally embedded through multifunctional and ritual roles, offering a novel methodological approach that can be applied in other ethnobotanical studies. Additionally, the structural composition of home gardens promotes ecological benefits, such as microclimate regulation and habitat provision for pollinators.

Overall, this study demonstrates how cultural, medicinal, and ecological functions are intertwined in rural Thai home gardens, providing insights for sustainable horticultural management, conservation of culturally and medicinally important species, and targeted ethnopharmacological research. Future research should employ systematic or stratified sampling to capture spatial variation and include long-term monitoring to assess seasonal changes and cultivation trends. In addition, studies should explore how specific traits and plant combinations influence microclimate regulation, providing deeper insight into the ecological services embedded within local gardening traditions.