Zingiberaceae in Roi Et Province, Thailand: Diversity, Ethnobotany, Horticultural Value, and Conservation Status

Abstract

Zingiberaceae is a diverse and culturally significant plant family across tropical Asia, yet in Roi Et Province, Thailand, it has remained poorly documented. This study aimed to provide the first comprehensive assessment of Zingiberaceae in Roi Et Province, Thailand. Previous studies in the region have been limited and did not systematically document species occurrence. The assessment began with an overview of species diversity, followed by an investigation of their ethnobotanical uses, an evaluation of their horticultural potential, and an assessment of their conservation status. Field surveys were conducted throughout Roi Et Province across various habitat types using exploratory sampling to record all observable Zingiberaceae species. Species were identified based on morphological characteristics and comparisons with existing taxonomic literature. A total of 97 species were recorded, including 86 native and 11 introduced taxa, with 23 species endemic to Thailand and 25 species featuring new distributions reported for the province. Species richness was highest in cultivated habitats, likely reflecting the active role of traditional agroecosystems in conserving both native and introduced taxa. Natural habitats such as wetlands and dry evergreen forests hosted species with restricted distributions, underscoring the need to preserve ecological heterogeneity. Ethnobotanical interviews revealed widespread local use of rhizomes and inflorescences for food, medicine, ornamentation, and ceremonial purposes. Phenological observations indicated synchronized flowering and fruiting aligned with the monsoon season, which are traits that supports successful reproduction but may also increase vulnerability under shifting climate regimes—highlighting the importance of monitoring for conservation and guiding optimal harvest timing. These findings demonstrate that both natural and cultivated systems are integral to maintaining Zingiberaceae diversity in the region. Conservation strategies should prioritize habitat protection, support traditional cultivation practices, and promote further research into economically and culturally valuable species.

1. Introduction

The Zingiberaceae family, commonly known as the ginger family, represents a diverse group of plants with significant ecological, cultural, and economic importance across tropical and subtropical regions [1,2,3]. Several species within this family are utilized in traditional medicine, cuisine, and ornamental horticulture [2,3,4,5].

In Thailand, Zingiberaceae contributes to both cultural heritage and the local economy, especially in provinces like Roi Et in the northeastern region [6,7]. These species not only serve as cultural and economic resources but also support local ecosystems through interactions with pollinators, understory structuring, and seasonal dynamics.

Despite this significance, Zingiberaceae species in Roi Et Province remain poorly documented—particularly in terms of taxonomy, distribution, ethnobotanical practices, horticultural potential, and conservation status. Most research on Zingiberaceae in Southeast Asia has focused on broad-scale diversity and taxonomy, with only limited studies conducted in Roi Et. To date, only the Nong Phok and Pathumrat Districts have been investigated [6,7], and no species records have been reported for the Flora of Thailand (Volume 16, Part 2) from the province [8]. These earlier studies primarily focused on species checklists and basic habitat descriptions but lacked integration with ethnobotanical, horticultural, and conservation perspectives, leaving a significant regional gap in understanding.

Additionally, existing ethnobotanical studies often treat the cultural uses of Zingiberaceae separately from their horticultural significance and conservation needs [9,10,11]. While local communities commonly use these species for food, medicine, ornamentation, and rituals [2,3], few studies have explored their potential in horticultural applications or assess their current conservation threats. This disconnect is problematic, particularly as habitat degradation and unsustainable harvesting continue to affect Zingiberaceae populations.

Climate change further compounds these threats by altering flowering times, habitat conditions, and species distributions [12], increasing the urgency for localized conservation strategies [13]. Addressing these challenges requires not only ecological and taxonomic assessments but also community-based approaches that incorporate traditional knowledge and promote sustainable horticultural practices. Strengthening local awareness and encouraging cultivation can support both biodiversity and livelihoods.

To address these gaps, this study aims to provide a comprehensive analysis of Zingiberaceae species in Roi Et Province, Thailand. Specifically, it investigates species diversity, documents ethnobotanical uses, evaluates horticultural potential, and assesses conservation status. By integrating field-based data with local knowledge, the findings aim to clarify the ecological roles and economic significance of these species in the region. Ultimately, this research supports the sustainable use and conservation of Zingiberaceae through strategies that align with community engagement and long-term biodiversity protection.

2. Materials and Methods

2.1. Study Area

Roi Et Province (Figure 1), situated in the northeastern floristic region of Thailand, provides an ideal setting for studying Zingiberaceae due to its diverse topography and unique ecological features. Covering an area of approximately 8317 square kilometers, the province is predominantly characterized by plains, with elevations ranging from 130 to 160 m above sea level, and is drained by the Chi River. The northern and eastern regions of the province are bordered by the Phu Phan Mountain range, creating diverse ecological zones, including fertile floodplains at the confluence of the Chi and Mun rivers. These diverse landscapes offer a variety of habitats that are likely to support a wide range of Zingiberaceae species, with each adapted to specific environmental conditions.

In addition, Roi Et Province is home to Thung Kula Rong Hai, a vast dry region that spans over five provinces, with the largest portion situated within Roi Et. This arid area, especially during the dry season, is known for cracked and parched soil, creating a harsh environment for plant life. The province’s combination of arid regions like Thung Kula Rong Hai and fertile floodplains creates distinct ecological gradients, providing unique opportunities to study how Zingiberaceae species adapt to various environmental pressures, such as drought and seasonal flooding.

The diverse habitats in Roi Et—ranging from wetlands to dry forest ecosystems—are significant for understanding the ecological roles and distribution of Zingiberaceae species. These areas also provide insight into the species’ resilience and adaptability in response to environmental changes. The distinctive environmental conditions in Roi Et, from the dry season in Thung Kula Rong Hai to the seasonal flooding of the river plains, are particularly relevant for studying species’ phenology, growth patterns, and conservation needs in the context of climate change.

The field survey period from January to December 2024 was specifically selected to capture seasonal variations in plant growth, phenology, and ecological changes throughout the year. This timeframe allows for the monitoring of plant behavior across different seasons, including the impact of the dry season on arid regions such as Thung Kula Rong Hai and the influence of monsoon rains on the wetlands and floodplains. By capturing these seasonal variations, we aim to gain a comprehensive understanding of how Zingiberaceae species in Roi Et respond to seasonal environmental fluctuations, which is essential for both their conservation and sustainable management.

2.2. Data Collection

Field surveys were carried out between January 2024 and December 2024 to document Zingiberaceae species across diverse habitats in Roi Et Province. These surveys, conducted two to four times per month, focused on a wide array of ecological zones, including forests, urban areas, and other accessible sites. Emphasis was placed on capturing species from different ecological contexts, ensuring a thorough representation of the province’s biodiversity. Special care was taken to minimize ecological disturbances in protected areas, where only photographic records and field notes were collected, and no plant specimens were collected, in order to maintain the integrity of the habitats [2,3].

2.3. Taxonomic Identification

Taxonomic identification was conducted by comparing the morphological characteristics of collected specimens with the original protologues and related taxonomic literature. Morphological traits were examined using precise measurements with rulers and vernier calipers (Mitutoyo Vernier Caliper, Mitutoyo Corporation, Kawasaki, Japan), and detailed observations were made under a stereoscopic microscope (Stemi 2000-C, Zeiss, Oberkochen, Germany). Key distinguishing features were focused on, including leaf shape, size, and venation pattern; flower morphology; and the arrangement of the inflorescence (e.g., thyrse, present of coma bracts, epigynous glands, and anther spurs). Special attention was given to flower structure, particularly the shape and color of the labellum and staminodes. Identification was performed using diagnostic keys and comparisons with descriptions provided in the Flora of Thailand Volume 16 Part 2 (Zingiberaceae family) [8]. The identification process was further supported by referencing herbarium specimens, relevant literature, and previously identified materials [14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82]. High-resolution specimen images were reviewed from major herbaria (A, AAU, B, BK, BKF, C, CAL, CMU, E, HITBC, K, KKU, KUN, L, M, MO, P, PE, QBG, and SING) via JSTOR Global Plants (accessed on 31 March 2025) and the Zingiberaceae Resource Center (accessed on 31 March 2025). This integrative approach ensured accurate identification and taxonomic consistency.

2.4. Plant Specimen Preservation

Specimens collected during the field surveys were preserved in 70% ethanol to maintain their morphological integrity. These preserved specimens were stored at a controlled room temperature of approximately 25 °C to prevent degradation. Subsequently, they were deposited at the Vascular Plant Herbarium, Mahasarakham University (VMSU) in Thailand, which serves as the repository for the collected samples, ensuring they are available for future reference and further study.

2.5. Study of Habitats of Zingiberaceae in Roi Et Province

During fieldwork, ecological information was recorded for each Zingiberaceae species to understand their habitat associations. The forest types were classified based on observable dominant vegetation and land use characteristics into six categories: deciduous dipterocarp forest (DD), deciduous forest (DC), dry evergreen forest (DE), evergreen forest (EV), mixed deciduous forest (MX), and wetland (WL). Additionally, cultivated species were recorded from home gardens and agricultural areas, marked as CV. Although direct field measurements of environmental parameters were not conducted, climate data from the Thai Meteorological Department were referenced to contextualize the environmental conditions of Roi Et Province. Based on historical records (1971–2000), the province has an average annual temperature of approximately 27.8 °C, with the highest monthly average in April (about 34.5 °C) and the lowest in December (around 21.2 °C). Average annual rainfall is approximately 1280 mm, with peak precipitation occurring in August, averaging around 220 mm. These environmental characteristics were considered when analyzing the distribution and ecological preferences of the species encountered.

2.6. Study of Phenology of Zingiberaceae in Roi Et Province

This study examines the phenology of Zingiberaceae in Roi Et Province, focusing on flowering and fruiting patterns. Each month was assigned a numerical value from 1 for January to 12 for December. Understanding these reproductive stages is essential for assessing the species’ reproductive success and economic significance. Although some species of Zingiberaceae do not undergo a dormant phase and grow year-round, we ensured that our study design captured their reproductive cycles by monitoring flowering and fruiting stages continuously throughout the year. This approach provided meaningful data on their reproductive patterns, despite the one-year study period. However, a complete evaluation of the full growth cycle was not feasible within this timeframe, highlighting the need for long-term monitoring. Further studies with extended observation periods would enhance our understanding of the reproductive cycles of these species across different environmental conditions [2,3].

2.7. Utilization

Data on the utilization of Zingiberaceae plants in Roi Et Province were obtained through interviews with 400 local residents, with an equal distribution of 10 males and 10 females from each district. This resulted in a total of 200 male and 200 female participants, all of whom were permanent residents and homeowners in the province (excluding those in rental housing). Before conducting the interviews, participants provided informed consent after receiving a clear explanation of the study’s objectives to ensure voluntary participation. The interview questions focused on identifying the local names of plants, the used parts, the preparation methods for their use, and the specific purposes of their use. No personal data were recorded, and therefore, the study did not require formal ethical approval [2,3]. Participants were selected based on their long-term residency and local familiarity with plant use rather than demographic factors such as age or education. Reported uses were cross-verified through repeated mentions among informants and compared with existing ethnobotanical literature when available.

The evaluation of the economic value of Zingiberaceae was carried out with an emphasis on the local economic context, specifically examining the dynamics between vendors of Zingiberaceae plants and their customers in the designated study area. This framework facilitated the application of quantitative research techniques complemented by botanical expertise to ensure accurate identification of the scientific names of commonly traded Zingiberaceae species in Roi Et Province. Participants in the study included both plant sellers and buyers.

2.8. Quantitative Analysis

2.8.1. Jaccard’s Similarity Index (JI)

To assess species diversity similarity across 20 districts, the Jaccard’s Similarity Index (JI) was employed. This index is a widely recognized method for measuring the similarity between two datasets [83]. In this study, it was used to evaluate the similarity in species composition among different ecological types in Roi Et Province. The Jaccard Similarity Index (JI) was chosen because it is specifically useful for comparing the presence or absence of species across different locations, making it highly relevant for studying plant diversity. Since our research focuses on comparing species distribution rather than abundance, JI’s binary approach (presence or absence) aligns with the nature of our data and the goal of examining ecological patterns. The Jaccard Similarity Index (JI) is calculated using the following formula:

$$\mathrm{JI}={\displaystyle \frac{\mathrm{a}}{\mathrm{a}+\mathrm{b}+\mathrm{c}}}$$

(1)

In the formula, the following are defined:

a = The number of species common to both districts.

b = The species unique to the first district.

c = The species exclusive to the second district.

By applying the Jaccard Similarity Index, species diversity across the districts was measured, enabling an objective comparison of their ecological compositions. This method revealed important patterns of similarity and difference in species presence, contributing to a better understanding of the biodiversity distribution in the study area.

Additionally, the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) was used to explore the similarities in species diversity across districts. The Jaccard Similarity Index was the foundation for creating a similarity matrix, which was then processed through the UPGMA algorithm. Clustering and dendrogram construction were carried out using Past4 software (version 4.15) [84]. The dendrogram visually displays the hierarchical relationships between districts based on their species compositions, helping to identify groups of districts with similar biodiversity profiles and providing a deeper insight into regional biodiversity trends.

2.8.2. Species Use Value (SUV): For One Species Across All Informants

The Species Use Value (SUV) quantifies the perceived importance of a Zingiberaceae species among the people of Roi Et Province. The SUV is calculated using the method applied from Phillips and Gentry [85] and Hoffman and Gallaher [86] and is expressed here as follows:

$$\mathrm{SUV}={\displaystyle \frac{\sum {\mathrm{U}\mathrm{V}}_{\mathrm{i}\mathrm{s}}}{{\mathrm{n}}_{\mathrm{i}}}}$$

(2)

In the formula, the following are defined:

UV_is = The use value of a species reported by a single informant. It is calculated as the total number of use citations for a given species by that informant (considering all uses as equal) divided by the total number of times that informant mentioned any use of the species (the number of use events recorded for that species by the informant over the study period).

n_i = The total number of informants.

The SUV is determined by summing the informant use values for a species and dividing by the total number of informants.

The range of Species Use Value (SUV) can exceed 1.0 if informants frequently cite a species across various uses, such as medicinal, culinary, and ceremonial purposes, indicating its high perceived importance. On the other hand, the minimum value is 0.0, meaning that if the SUV value is close to 0.0, the species was not cited by any informants or does not hold any perceived significance in the community.

To mitigate potential biases in the data collection process, several steps were taken to ensure the reliability of informant responses. First, a diverse set of informants from different backgrounds and age groups was selected to capture a wide range of perspectives. Efforts were made to minimize the influence of dominant individuals who may overemphasize certain species or uses. Interviews were also structured to encourage open-ended responses, allowing informants to express their knowledge freely without being influenced by predefined categories or assumptions. In addition, repeated interviews with a subset of informants were conducted to check for consistency in reported use values. Finally, to avoid social desirability bias, all interviews were conducted in a neutral setting where informants felt comfortable sharing their knowledge without external pressures. These measures helped to reduce potential biases and ensured that the reported use values more accurately reflected the true perceptions of the local community.

2.8.3. Genera Use Value (GUV)

The Genera Use Value (GUV) reflects the perceived significance of a Zingiberaceae genus by the people of Roi Et Province. The GUV is calculated using the method proposed by Phillips and Gentry [85] and Hoffman and Gallaher [86] and is expressed as follows:

$$\mathrm{GUV}={\displaystyle \frac{\sum \mathrm{SUV}}{{\mathrm{N}}_{\mathrm{s}}}}$$

(3)

In the formula, the following are defined:

∑SUV = The total of the species uses values in the same genus.

N_s = The total number of species withing a given genus.

The GUV is calculated by summing the use values for all the species within a given genus and dividing by N_s.

The Genera Use Value (GUV) is calculated by averaging the Species Use Values (SUVs) of all species within a particular genus. The maximum value of GUV occurs when all species within the genus are highly cited and used for multiple purposes, leading to a high average value. It is possible for the GUV to exceed 1.0 if all species within the genus have an SUV greater than 1.0. On the other hand, the minimum value of GUV is 0.0, which means that none of the species in the genus were cited or used by informants. When the GUV value is near 0.0, it indicates that the genus holds little or no perceived significance or utility within the community [85,86].

2.8.4. Relative Frequency of Citation (RFC)

The Relative Frequency of Citation (RFC) [87] was used to determine the frequency of use of specific plant species, which is calculated using the following formula:

RFC = FC/N

(4)

In the formula, the following are defined:

RFC = Relative Frequency of Citation;

FC = Number of informants who cited a particular Zingiberaceae plant;

N = Total number of informants surveyed.

The RFC values range from 0 to 1, with higher values signifying greater cultural and dietary importance of a plant in the region. This measure was employed to rank Zingiberaceae plants based on their relative significance, offering a quantitative assessment of their utilization [87].

2.8.5. Informant Consensus Factor (Fic)

The Informant Consensus Factor (Fic) is an index used to assess the level of consensus among informants regarding the use of medicinal plants. The Fic values range from 0 to 1, with a value close to or equal to 1 indicating a high degree of agreement among informants. A higher Fic value suggests that a medicinal plant is widely accepted and consistently recognized for its therapeutic use. This consistency is crucial in validating the potential benefits of medicinal plants [88,89]. The Fic is calculated using the following formula:

Fic = (n_ur − n_t)/(n_ur − 1)

(5)

where n_ur = total number of reports documenting the specific use of a plant species for a particular disease syndrome across all informants, and n_t = total number of plant species used for the same condition. This index provides insight into the reliability and acceptance of traditional medicinal knowledge within a community.

2.8.6. Fidelity Level (%FL)

The Fidelity Level (%FL) index is used to identify plant species that hold the highest interest for their potential application in treating diseases associated with specific syndromes. Since multiple plants may be used for the treatment of each syndrome, this index helps determine the most preferred species [90]. The %FL is calculated using the following formula:

%FL = (I_p/I_u) × 100

(6)

where I_p = number of reports documenting the use of a particular plant species for a specific diagnosis, and I_u = total number of plant utilization reports across all syndromes. A higher %FL value indicates a stronger preference for a plant in treating a specific condition, reflecting its perceived effectiveness within the community.

The maximum value of %FL is 100%, which occurs when all reports for a specific syndrome cite the same plant species, indicating that it is the most preferred or commonly used for treating that condition. Conversely, the minimum value of %FL is 0%, which means that no reports document the use of a particular plant species for the treatment of a specific condition, indicating that the species is not considered effective or is not used for that syndrome in the community. When the value is near 0%, it signifies that the species is rarely or never cited for the treatment of a particular condition, while a value closer to 100% indicates strong preference for that species for treating a specific condition [2].

2.8.7. Economic Value (EV)

The research focused on plant species actively traded in local markets. Price data were systematically gathered at four-month intervals over a one-year period (from October 2023 to September 2024). To assess EV, the average price consumers were willing to pay for each species was estimated by calculating the mean of the highest and lowest recorded prices [37]. The following formula was used to determine the annual economic value:

EV = AP × SM × SP

(7)

where AP = average price per kilogram (THB/kg), SM = total quantity sold monthly (kg), and SP = number of months the species is sold annually.

This formula quantifies the total yearly income generated from the sale of each plant species. For ornamental species sold as whole plants, the economic value was determined using a method adapted from Saensouk et al. [37], as shown below:

Annual Economic Value = Np × Pp

(8)

where Np = number of pots sold per year, and Pp = average price per pot.

Average Price Determination and Market Stability: The method for calculating the economic value (EV) of Zingiberaceae species in the study area is based on market price data collected from local vendors over a one-year period (October 2023 to September 2024). For species sold by weight, the “average price per kilogram” (AP) was calculated by averaging the highest and lowest prices recorded for each species during the four-month intervals. Price data were collected from a range of vendors to ensure accurate and representative price estimates for each species.

Price Stability: It is important to note that some species exhibited seasonal price fluctuations, particularly those influenced by their availability or growth cycles. For example, species with high seasonal availability or those dependent on weather conditions showed minor price variations during the year. However, the prices of ornamental species that were consistently available throughout the year remained relatively stable. In the analysis, these seasonal fluctuations were accounted for by taking the mean of the highest and lowest prices observed during the survey periods, ensuring that the calculated economic values are robust and reflective of market dynamics.

2.9. Conservation Status

The conservation status of wild Zingiberaceae species in Roi Et Province was proposed by the authors following the IUCN Red List criteria [13]. In this study, species were evaluated based on their population size, habitat distribution, and threats they face, including habitat loss, over-collection, and climate change. Species with limited distribution and those observed in vulnerable habitats, such as dry evergreen forests and wetlands, were prioritized for conservation status assessment. For example, Boesenbergia parvula and Kaempferia mahasarakhamensis, which are primarily found in specific ecological zones, were identified as potentially threatened due to their restricted range and increasing anthropogenic pressures. The proposed conservation status was categorized as Least Concern (LC), Near Threatened (NT), Vulnerable (VU), or Endangered (EN) depending on the species’ relative risk. This evaluation aims to provide essential information for the conservation of Zingiberaceae species in the region and contribute to broader efforts to protect plant biodiversity in Thailand.

3. Results

3.1. Species Diversity of Zingiberaceae in Roi Et Province

The species diversity of Zingiberaceae in Roi Et Province includes a total of ninety-seven species across thirteen genera (

Table 1. Species diversity of Zingiberaceae in Roi Et Province, northeastern Thailand, including vernacular names, distribution status in Thailand, occurrence, habitats, phenology, utilization, SUVs and RFC values, conservation status (IUCN and authors’ proposal), and voucher specimens.

No.	Scientific Name	Vernacular Name	Distribution for Thailand	Occurrence 1	Habitats 2	Phenology 3		Utilization 4		SUV	RFC	Conservation Status 5		Voucher Specimens
						Flowering	Fruiting	Purpose	Used Parts			IUCN	Author Proposed
1.	Alpinia conchigera Griff.	Kha Ling	Native	C	CV	6–9	8–9	FD, MP, SP	Rz, In	0.068	0.038	LC		ZR001
2.	Alpinia galanga (L.) Willd.	Kha	Native	B	DE, CV	5–9	7–10	CC, FD, MP, SP	Rz, Ps, In, Lv, Wp	2.043	0.920	NE	LC	ZR002
3.	Alpinia laosensis Gagnep.	Kha Ling Dok Daeng	Native	B	DE, EV, CV	6–9	7–10	FD	Ps, In	0.013	0.013	NE	LC	ZR003
4.	Alpinia latilabris Ridl.	Kha Pa	Native	B	DE, EV, CV	11–2	2–4	FD, ON, SP	Rz, Ps, In, Wp	0.025	0.010	LC	LC	ZR004
5.	Alpinia mutica Roxb.	Wan Saneh Haa	Native	C	CV	3–8	5–10	FD, MP, ON, RB	Rz, Ps, In, Wp	0.213	0.128	LC		ZR005
6.	Alpinia purpurata (Vieill.) K.Schum.	Kha Daeng	Introduced	C	CV	1–12	Not seen	CC, ON	In, Wp	0.210	0.165	NE		ZR006
7.	Alpinia siamensis K.Schum.	Kha Ta Daeng	Native	C	CV	5–8	7–11	CC, FD, MP, SP	Rz, Ps, In	2.505	0.988	NE		ZR007
8.	Alpinia vittata W.Bull	Kha Daang	Introduced	C	CV	6–8	7–9	CC, ON, RB	Wp	0.135	0.058	NE		ZR008
9.	Amomum foetidum Boonma and Saensouk	Ton Maeng Khaeng	Endemic	C	CV	1–3	Not seen	FD	Wp	0.068	0.068	NE		ZR009
10.	Amomum repoeense Pierre ex Gagnep.	Raiw Pa	Native	B	DE, EV, CV	4–7	6–9	FD	Ps	0.008	0.008	LC	LC	ZR010
11.	Amomum trilobum Gagnep.	Pud Nhoo	Native	C	CV	5–6	6–9	RB	Wp	0.083	0.083	NE		ZR011
12.	Amomum wandokthong (Picheans. and Yupparach) Škorničk. and Hlavatá	Wan Dok Thong	Endemic	C	CV	4–10	Not seen	RB	Wp	0.135	0.135	NE		ZR012
13.	Boesenbergia parvula (Wall. ex Baker) Kuntze	Ka Tue Ling	Native	W	EV	7–9	9–10	NA	–	0.000	0.000	LC	EN	ZR013
14.	Boesenbergia rotunda (L.) Mansf.	Kha Chai	Native	B	MX, DE, CV	7–9	9–10	CC, FD, MP, SP	Rt, Rz, Ps	1.933	0.980	LC	VU	ZR014
15.	Boesenbergia xiphostachya (Gagnep.) Loes.	Ngon Nark	Native	B	DC, DE, CV	5–8	8–10	MP, RB	Rz, In, Wp	0.058	0.030	LC	VU	ZR015
16.	Cornukaempferia argentifolia Boonma and Saensouk	Proh Thong Bai Ngern	Endemic	C	CV	7–9	8–10	ON	Wp	0.008	0.008	NE		ZR016
17.	Cornukaempferia srisumoniae P.Saensouk, Saensouk, and Boonma	Proh Thong Srisumon	Endemic	C	CV	7–9	8–10	ON	Wp	0.005	0.005	NE		ZR017
18.	Curcuma aeruginosa Roxb.	Wan Maha Mek	Native	C	CV	3–6	Not seen	FD, MP, ON	Rz, In, Wp	0.133	0.090	LC		ZR018
19.	Curcuma alismatifolia Gagnep.	Krachiao, Pathumma	Native	C	CV	7–9	8–10	FD, ON	In, Wp	0.178	0.120	NT		ZR019
20.	Curcuma amada Roxb.	Kha Min Khaow Pa	Native	C	CV	7–9	Not seen	MP	Rz	0.028	0.028	NE		ZR020
21.	Curcuma amarissima Roscoe	Kha Min Dum	Native	C	CV	3–5	Not seen	MP	Rz	0.063	0.063	NE		ZR021
22.	Curcuma angustifolia Roxb.	Krachiao Daeng	Native	B	DC, CV	3–9	5–10	CC, FD, MP	Rz, In, Wp	1.203	0.805	NE	LC	ZR022
23.	Curcuma aromatica Salisb.	Wan Nang Kham	Native	C	CV	3–5	4–10	CM, MP	Rz	0.173	0.153	NE		ZR023
24.	Curcuma borealis Saensouk, P.Saensouk, and Boonma	Krachiao Thep Apsorn	Endemic	C	CV	4–7	7–9	ON	Wp	0.078	0.078	NE		ZR024
25.	Curcuma caesia Roxb.	Wan Mek Sit	Introduced	C	CV	4–5	Not seen	MP, RB	Rz, Wp	0.030	0.020	NE		ZR025
26.	Curcuma campanulata (Kuntze) Škorničk.	Wan Duk Dae	Native	B	DC, CV	3–5	Not seen	RB	Wp	0.005	0.005	NE	VU	ZR026
27.	Curcuma clovisii Škorničk.	Jok Daeng	Native	C	CV	5–6	6–9	ON	Wp	0.020	0.020	NE		ZR027
28.	Curcuma comosa Roxb.	Wan Chuck Mod Look	Native	C	CV	3–5	Not seen	CC, CM, MP	Rz, Wp	0.173	0.135	NE		ZR028
29.	Curcuma gracillima Gagnep.	Krachiao Jew	Native	C	CV	6–8	8–10	ON	Wp	0.010	0.010	LC		ZR029
30.	Curcuma harmandii Gagnep.	Chor Morrakot	Native	C	CV	7–9	8–10	ON, RB	Wp	0.050	0.028	LC		ZR030
31.	Curcuma involucrata (King ex Baker) Škorničk.	Wan Phet Noi	Native	B	DC, CV	5–6	6–8	ON	Wp	0.013	0.013	NE	VU	ZR031
32.	Curcuma longa L.	Kha Min, Kha Min Chan	Introduced	C	CV	7–9	8–10	CC, CM, FD, MP, RB, SP	Rz, In, Wp	1.863	0.970	DD		ZR032
33.	Curcuma mangga Valeton and Zijp	Kha Min Khaow	Introduced	C	CV	3–5	5–6	CC, FD, SP	Rz, In	0.935	0.780	DD		ZR033
34.	Curcuma parviflora Wall.	Wan Thep Ram Luek	Native	B	DC, DE, CV	7–9	8–10	ON	Wp	0.280	0.280	NE	VU	ZR034
35.	Curcuma pedicellata (Chaveer. and Mokkamul) Škorničk.	Wan Phet Phraiwan	Endemic	C	CV	6–8	Not seen	ON, RB	Wp	0.050	0.030	NE		ZR035
36.	Curcuma peninsularis Saensouk, P.Saensouk, Maknoi, and Boonma	Krachiao Ploy Andaman	Endemic	C	CV	6–9	Not seen	ON	Wp	0.058	0.058	NE		ZR036
37.	Curcuma peramoena Souvann. and Maknoi	Wan Houa Noi	Native	C	CV	6–8	Not seen	RB	Wp	0.015	0.015	NE		ZR037
38.	Curcuma petiolata Roxb.	Bua Chan	Native	C	CV	7–9	8–10	ON, RB	Wp	0.228	0.170	DD		ZR038
39.	Curcuma phrayawan Boonma and Saensouk	Phraya Wan	Endemic	C	CV	7–9	8–10	MP, RB	Rz, Wp	0.103	0.053	NE		ZR039
40.	Curcuma rangjued Saensouk and Boonma	Rang Jued	Native	C	CV	7–9	8–10	MP	Rz	0.118	0.118	NE		ZR040
41.	Curcuma rosea P.Saensouk, Saensouk, and Boonma	Maha Udom Umawadee	Endemic	C	CV	7–9	8–10	RB	Wp	0.018	0.018	NE		ZR041
42.	Curcuma rubescens Roxb.	Wan Mahaprab	Introduced	C	CV	3–5	4–7	ON, RB	Wp	0.078	0.055	NE		ZR042
43.	Curcuma saraburiensis Boonma and Saensouk	Wan Klom Nang None	Endemic	C	CV	7–9	8–10	RB	Wp	0.005	0.005	NE		ZR043
44.	Curcuma siamensis Saensouk and Boonma	Kha Min Siam	Endemic	C	CV	7–9	8–10	RB	Wp	0.008	0.008	NE		ZR044
45.	Curcuma singularis Gagnep.	Krachiao Khaow, Dok Din	Native	B	DC, CV	3–6	5–7	CC, FD	Rz, In	1.325	0.988	NE	VU	ZR045
46.	Curcuma suraponii Boonma	Wan Krabi Thong	Endemic	C	CV	7–9	Not seen	ON, RB	Wp	0.125	0.108	NE		ZR046
47.	Curcuma thorelii Gagnep.	Krachiao Khaow	Native	B	DC, DE, CV	7–9	8–10	ON, RB	Wp	0.163	0.128	NE	VU	ZR047
48.	Curcuma ubonensis Boonma, Saensouk, Maknoi, and P.Saensouk	Krachiao Ubon	Endemic	C	CV	7–9	8–10	ON	Wp	0.005	0.005	NE		ZR048
49.	Curcuma wanchaii Saensouk, P.Saensouk, Maknoi, and Boonma	Krachiao Wanchaii	Endemic	C	CV	7–9	8–10	ON	Wp	0.005	0.005	NE		ZR049
50.	Curcuma wanenlueanga Saensouk, Thomudtha, and Boonma	Wan Enlueang	Endemic	C	CV	7–9	8–10	CC, MP	Rz	0.103	0.080	NE		ZR050
51.	Etlingera elatior (Jack) R.M.Sm.	Da La	Native	C	CV	1–12	1–12	CC, FD, ON	Wp	0.313	0.273	DD		ZR051
52.	Gagnepainia godefroyi (Baill.) K.Schum.	Wan Phet Na Tang	Native	C	CV	4–6	Not seen	ON, RB	Wp	0.043	0.030	LC		ZR052
53.	Gagnepainia harmandii (Baill.) K.Schum.	Wan Morrakot	Native	B	DE, CV	4–6	Not seen	ON, RB	Wp	0.035	0.028	NE	VU	ZR053
54.	Globba cambodgensis Gagnep.	Khaophansa Hu Kra Tai	Native	C	CV	6–8	8–10	ON, RB	Wp	0.025	0.013	NE		ZR054
55.	Globba cernua Baker	Pud Hin	Native	C	CV	6–8	8–10	ON, RB	Wp	0.068	0.053	LC		ZR055
56.	Globba conferta M.F.Newman	Khaophansa Chor Tab Tim	Endemic	B	DC, DE, CV	6–8	8–10	ON, RB	Rz, Wp	0.165	0.085	LC	VU	ZR056
57.	Globba laeta K.Larsen	Khaophansa Khaow	Native	C	CV	6–9	8–9	ON, RB	Wp	0.100	0.085	EN		ZR057
58.	Globba marantina L.	Wan E Moob	Native	B	DC, DE, CV	7–9	8–10	ON	Wp	0.020	0.020	LC	LC	ZR058
59.	Globba pendula Roxb.	Pud Nok Yoong	Native	C	CV	6–7	Not seen	ON, RB	Wp	0.030	0.023	LC		ZR059
60.	Globba rosea Gagnep.	Khaophansa Chor Chomphoo	Native	B	DC, DE, CV	7–9	8–10	CC, ON, RB	Rz, Wp	0.113	0.045	NE	VU	ZR060
61.	Globba sherwoodiana W.J.Kress and V.Gowda	Khaophansa Khaow Phama	Native	C	CV	7–9	8–10	ON, RB	Wp	0.140	0.140	NE		ZR061
62.	Globba schomburgkii Hook.f.	Khaophansa	Native	B	DC, DE, CV	7–9	8–10	ON	Wp	0.088	0.053	NE	LC	ZR062
63.	Globba williamsiana M.F.Newman and Sangvir.	Hong Hern	Endemic	C	CV	7–9	8–10	ON, RB	Wp	0.365	0.190	NE		ZR063
64.	Hedychium coronarium J.Koenig	Sa Le Te	Native	C	CV	7–9	8–10	CC, FD, MP, ON, RB	Rz, Wp	0.223	0.120	DD		ZR064
65.	Kaempferia angustifolia Roscoe	Wan Prab Samut	Native	C	CV	7–9	8–10	CC, MP, RB	Rz, Wp	0.158	0.060	LC		ZR065
66.	Kaempferia elegans Wall.	Wan Nok Khoom	Native	C	CV	7–9	8–10	CC, MP, ON, RB	Rz, Wp	0.268	0.135	NE		ZR066
67.	Kaempferia galanga L.	Wan Proh Hom	Native	B	DC, CV	7–9	8–10	FD, MP, RB	Rz, Wp	0.175	0.085	DD	VU	ZR067
68.	Kaempferia gilbertii W.Bull	Wan Maha Niyom	Introduced	C	CV	7–9	8–10	ON, RB	Wp	0.090	0.053	NE		ZR068
69.	Kaempferia isanensis Saensouk and P.Saensouk	Toob Moob Isan	Endemic	B	DC, CV	5–6	8–9	FD, SP	Rz, Lv	0.055	0.040	NE	VU	ZR069
70.	Kaempferia mahasarakhamensis Saensouk and P.Saensouk	Toob Moob Sarakham	Endemic	B	DC, WL, CV	6–8	8–9	FD	In, Ps	0.043	0.043	NE	EN	ZR070
71.	Kaempferia marginata Carey ex Roscoe	Toob Moob	Native	B	DC, CV	7–9	8–10	FD, MP	Rz, Lv	0.235	0.213	NE	LC	ZR071
72.	Kaempferia parviflora Wall. ex Baker	Kra Chai Dam	Native	C	CV	7–9	8–10	MP	Rz	0.215	0.215	DD		ZR072
73.	Kaempferia pulchra Ridl.	Proh Pa	Native	C	CV	6–9	Not seen	ON	Wp	0.030	0.030	NE		ZR073
74.	Kaempferia rotunda L.	Wan Haow None	Native	B	DC, CV	3–5	5–6	FD, MP, ON, RB	Rz, Wp	0.445	0.230	NE	VU	ZR074
75.	Kaempferia sakolchaii P.Saensouk, Saensouk, and Boonma	Proh Bai Lai Taeng Mo	Endemic	B	DC, DE, CV	5–7	Not seen	ON	Wp	0.010	0.010	NE	VU	ZR075
76.	Kaempferia sakonensis Saensouk, P.Saensouk, and Boonma	Proh Sakon	Endemic	W	DC, DE	6–9	Not seen	ON	Wp	0.030	0.030	NE	VU	ZR076
77.	Kaempferia sipraiana Boonma and Saensouk	Proh Siprai	Endemic	C	CV	4–5	Not seen	ON	Wp	0.005	0.005	NE		ZR077
78.	Meistera chinensis (Chun ex T.L.Wu) Škorničk. and M.F.Newman	Raew Pa	Native	W	DE, EV	4–5	Not seen	NA	-	0.000	0.000	LC	LC	ZR078
79.	Wurfbainia schmidtii (K.Schum.) Škorničk. and A.D.Poulsen	Wan Saow Long	Native	B	DE, EV, CV	5–6	6–9	FD, ON, RB, CM	Rz, Wp	0.168	0.108	LC	LC	ZR079
80.	Wurfbainia uliginosa (J.Koenig) Giseke	Raew	Native	B	DE, EV, CV	4–7	5–8	FD, MP, SP	Rz, In	0.083	0.033	LC	LC	ZR080
81.	Wurfbainia vera (Blackw.) Škorničk. and A.D.Poulsen	Krawan	Native	C	CV	4–7	5–8	MP, SP	Rz, Fr	0.063	0.048	DD		ZR081
82.	Wurfbainia villosa (Lour.) Škorničk. and A.D.Poulsen	Mak Naeng	Native	B	DE, EV, CV	5–9	8–11	FD, MP	Rz, Fr	0.028	0.020	DD	LC	ZR082
83.	Zingiber chrysostachys Ridl.	Khing Pa	Native	C	CV	7–9	9–10	ON	In, Wp	0.003	0.003	EN		ZR083
84.	Zingiber citriodorum Theilade and Mood	Ta Krai Pran	Endemic	C	CV	4–5	5–7	FD, MP, RB	Rz, Wp	0.043	0.035	NE		ZR084
85.	Zingiber isanense Triboun and K.Larsen	Khing Isan	Native	B	DC, DE, CV	5–7	6–8	FD, MP	Rz, Ps, In	0.070	0.070	LC	VU	ZR085
86.	Zingiber junceum Gagnep.	Khing Kra Tai	Native	B	DC, DE, CV	7–9	Not seen	FD, ON	In, Wp	0.278	0.260	LC	VU	ZR086
87.	Zingiber ligulatum Roxb.	Khing Haeng	Introduced	C	CV	6–8	8–10	MP	Rz	0.008	0.008	DD		ZR087
88.	Zingiber mekongense Gagnep.	Khing Mae Kong	Native	B	DE, CV	4–7	Not seen	MP	Rz	0.033	0.033	NE	VU	ZR088
89.	Zingiber montanum (J.Koenig) Link ex A.Dietr.	Wan Fai	Native	C	CV	3–5	Not seen	FD, MP, RB, CM	Rz, Wp	0.303	0.203	NE		ZR089
90.	Zingiber officinale Roscoe	Khing	Introduced	C	CV	7–9	8–10	CC, FD, MP, SP	Rz, Ps, Lv, In	2.105	0.980	DD		ZR090
91.	Zingiber ottensii Valeton	Plai Dam	Introduced	C	CV	7–9	8–10	FD, MP, RB	Rz, In, Ps, Wp	0.138	0.053	DD		ZR091
92.	Zingiber purpureum Roscoe	Plai Lueang	Introduced	C	CV	3–6	Not seen	MP, RB	Rz, Wp	0.265	0.220	DD		ZR092
93.	Zingiber pyroglossum Triboun and K.Larsen	Plai Dok Lueang	Native	B	DE, EV, CV	7–9	8–10	FD, MP, ON	Rz, In, Wp	0.083	0.035	LC	VU	ZR093
94	Zingiber rubens Roxb.	Khing Paa	Native	B	DE, EV, CV	7–9	8–9	FD, RB	In, Wp	0.060	0.055	NE	VU	ZR094
95	Zingiber spectabile Griff.	Katue Pilat	Native	C	CV	7–9	8–9	FD, MP, ON, RB	Rz, In, Wp	0.018	0.008	DD		ZR095
96	Zingiber thorelii Gagnep.	Dok Din	Native	B	DE, EV, CV	7–9	9–10	FD	In	0.080	0.080	LC	VU	ZR096
97	Zingiber zerumbet (L.) Roscoe ex Sm.	E-Tue	Native	B	DE, DC, EV, CV	5–8	8–10	FD, MP	In, Ps	0.163	0.133	DD	LC	ZR097

¹ Occurrence: W = found only in the wild; C = found only in cultivation; B = found both situations. ² Habitats: DD = deciduous dipterocarp forest; DC = deciduous forest; DE = dry evergreen forest; EV = evergreen forest; MX = mixed deciduous forest; WL = wetland; CV = cultivated. ³ Phenology: 1 = January; 2 = February; 3 = March; 4 = April; 5 = May; 6 = June; 7 = July; 8 = August; 9 = September; 10 = October; 11 = November; 12 = December. ⁴ Utilization: FD = food; MP = medicinal plant; ON = ornamental plant; RB = rituals and beliefs; CM = cosmetics; CC = commercial cultivation; NA = No reported use; Rz = rhizomes; Ps = pseudostems; Lv = leaves; In = inflorescences; Wp = whole plant. ⁵ Conservation status: DD = Data Deficient; NE = Not evaluated; LC = Least Concern; VU = Vulnerable; EN = Endangered; CR = Critically Endangered. Note: The gray background color of the cell indicates that the species is not found in the wild of Roi Et Province.

, Tables S1 and S2, Figure 2). Twenty-five species represent new distribution reports for the province, including Alpinia laosensis, A. latilabris, Amomum repoeense, Boesenbergia parvula, Curcuma campanulata, C. involucrata, C. parviflora, C. thorelii, Gagnepainia harmandii, Globba conferta, G. marantina, G. rosea, Kaempferia galanga, K. isanensis, K. mahasarakhamensis, K. sakolchaii, K. sakonensis, Meistera chinensis, Wurfbainia schmidtii, W. uliginosa, Zingiber isanense, Z. junceum, Z. mekongense, Z. pyroglossum, and Z. thorelii.

Curcuma exhibited the highest species richness, with 33 species recorded, making it the most diverse genus in the region. Other notable genera include Zingiber (15 species), Kaempferia (13 species), Globba (10 species), and Alpinia (eight species). Amomum and Wurfbainia each contributed four species, while Boesenbergia was represented by three species. Cornukaempferia and Gagnepainia each had two species. Etlingera, Hedychium, and Meistera were each represented by a single species.

Among these species, 11 are introduced, including Alpinia purpurata, A. vittata, Curcuma caesia, C. longa, C. mangga, C. rubescens, Kaempferia gilbertii, Zingiber ligulatum, Z. officinale, Z. ottensii, and Z. purpureum. The remaining are native to Thailand, with 23 species of them being endemic to the country, including Amomum foetidum, A. wandokthong, Cornukaempferia argentifolia, Cornukaempferia srisumoniae, Curcuma borealis, C. pedicellata, C. peninsularis, C. phrayawan, C. rosea, C. saraburiensis, C. siamensis, C. suraponii, C. ubonensis, C. wanchaii, C. wanenlueanga, Globba conferta, G. williamsiana, Kaempferia isanensis, K. mahasarakhamensis, K. sakolchaii, K. sakonensis, K. sipraiana, and Zingiber citriodorum.

The occurrence of these 97 species reveals interesting patterns in their distribution. Thirty-six species were found in the wild. Among these, three species were exclusively found in the wild and were not observed in cultivation, while 33 species occurred in both wild and cultivated environments. In contrast, 61 species were recorded only in cultivation (Figure 3). This highlights the diverse ecological presence and cultivation practices for these species.

3.1.1. Habitats

When analyzed using data from this study, the similarity analysis employing the Jaccard Index and UPGMA clustering method revealed clear patterns in the distribution of Zingiberaceae species across different ecological habitats (Figure 4). The numerical results showed that mixed deciduous forest (MX) separated first with a very low similarity to other habitats (MX–other habitats similarity ≈ 0.010), followed by wetland (WL), which formed a distinct cluster with low similarity to other habitats (WL–other habitats similarity ≈ 0.015). The cultivated areas (CV) and deciduous forest (DC) formed a cluster with a similarity of ≈0.211, while the dry evergreen forest (DE) and evergreen forest (EV) clustered together with a higher similarity of ≈0.407. The similarity between the two clusters, (CV–DC) vs. (DE–EV), was ≈0.182, indicating that these two groups, although distinct, share some overlap in species composition. These results suggest that species in cultivated areas are often closely related to those in nearby natural habitats like deciduous forests and evergreen forests. In contrast, the MX and WL habitats contain species that are more specialized and less commonly found in cultivation. The dendrogram clearly illustrates these patterns of ecological distribution, and the cophenetic correlation coefficient of ≈ 0.8755 confirms the robustness and reliability of the clustering analysis.

3.1.2. Phenology

The flowering and fruiting phenology (Figure 5) of Zingiberaceae species in Roi Et province reveals a distinct seasonal pattern that is closely tied to the regional climate. Flowering begins at a low level in January and gradually increases during the dry season. A sharp rise is observed from March through July, culminating in a peak flowering period in July, with about 73 species in bloom. This peak aligns with the early to mid-rainy season, when increased moisture and suitable temperatures favor the reproductive development of many tropical geophytes. Fruiting follows a delayed but corresponding pattern. While few species produce fruits early in the year, fruiting activity increases progressively from May onward. The highest number of fruiting species was recorded in August and September, with more than 60 species bearing fruits. This lag between peak flowering and peak fruiting reflects the natural progression of fruit development following successful pollination. After September, both flowering and fruiting activities decline sharply. By October, flowering is nearly absent, while fruiting persists at a reduced level. From November to January, very few species show reproductive activity, indicating a period of dormancy, likely due to reduced rainfall and cooler temperatures typical of the dry season in northeastern Thailand.

This phenological pattern reflects strong seasonal synchronization, suggesting that Zingiberaceae species in Roi Et rely heavily on monsoonal cues for their reproductive cycles. These data are valuable for planning fieldwork, as the peak flowering season (especially July) is ideal for taxonomic and ecological studies, while fruit and seed collection efforts should focus on August and September. Furthermore, understanding this pattern provides insight into how future climatic changes might impact the phenology, reproductive success, and conservation of these ecologically and economically important plants.

3.2. Ethnobotany: Utilization of Zingiberaceae in Roi Et Province

This study in Roi Et Province recorded 97 species from 13 genera of Zingiberaceae. Among these, 95 species had reported uses for various purposes, including food, spices, ornamentals, commercial cultivation, cosmetics, rituals and beliefs, and medicine. Two species from two genera had no reported uses: Boesenbergia parvula and Meistera chinensis.

3.2.1. Zingiberaceae Species Used as Food

Among the Zingiberaceae species used as food (Figure 6 and Table S3), species diversity is highest in the genus Zingiber, with 11 species recorded. This is followed by Curcuma and Alpinia, each with six species, and Kaempferia with five species. Wurfbainia contributes three species, Amomum two species, and Boesenbergia, Etlingera, and Hedychium are each represented by a single species. The genera Cornukaempferia, Gagnepainia, Globba, and Meistera were not recorded as food sources in this study. Regarding the plant parts used for food, inflorescences are the most frequently utilized, accounting for 44% of total usage, followed by rhizomes at 28%, pseudostems at 16%, and leaves at 10%. Fruits and seeds are the least commonly used, making up only 2%. These results emphasize the culinary importance of Zingiber species and highlight the predominance of inflorescences as the primary plant part consumed in traditional food practices.

3.2.2. Zingiberaceae Species Used as Spices

Among the Zingiberaceae species used as spices (Figure 7 and Table S4), Alpinia is the most represented genus, with four species recorded, followed by Curcuma and Wurfbainia, each with two species. Boesenbergia, Kaempferia, and Zingiber are each represented by a single species, while the remaining genera—Amomum, Cornukaempferia, Etlingera, Gagnepainia, Globba, Hedychium, and Meistera—have no species documented for spice use. Regarding the plant parts utilized, rhizomes are the most commonly used, accounting for 60% of the total, followed by pseudostems at 26.66%. Roots and fruits/seeds contribute 6.67% each, while leaves and inflorescences are not employed in spice applications. These findings highlight the dominant role of rhizomes in spice preparation and the notable contribution of Alpinia species to this category of use.

3.2.3. Zingiberaceae Species Used for Ornamentals

Among the Zingiberaceae species used as ornamentals (Figure 8 and Table 1), Curcuma stands out with the highest number of species, totaling sixteen. This is followed by Globba with ten species and Kaempferia with seven species. Alpinia and Zingiber are each represented by four species, Cornukaempferia and Gagnepainia by two species each, while Etlingera, Hedychium, and Wurfbainia are represented by one species each. In contrast, Amomum, Boesenbergia, and Meistera have no species recorded for ornamental use. With regard to plant parts, all ornamental uses involve the whole plant, accounting for 100% of usage, specifically for outdoor landscaping and garden decoration, as there were no reports of cut flower use in Roi Et Province. These results underscore the visual appeal of the entire plant form, particularly in Curcuma, and reflect the importance of overall aesthetic value in ornamental applications of Zingiberaceae.

In local communities, villagers commonly grow ornamental Zingiberaceae species around their homes to enhance the natural beauty of their surroundings. These plants are often used to decorate the fronts of houses—arranged in neat rows along walkways or near entrances. Some are planted in pots and displayed on porches or verandas, allowing for seasonal repositioning and ease of care. Others are cultivated in backyard gardens, where their vibrant foliage and striking inflorescences add color and texture to the landscape. This traditional use of ginger plants reflects not only their ornamental appeal but also the close relationship between local people and their surrounding plant biodiversity.

3.2.4. Zingiberaceae Species Used for Commercial Cultivation

A total of nine genera of Zingiberaceae plants were utilized for commercial cultivation in Roi Et Province (Figure 9). Among these, Curcuma had the highest number of species, with six species cultivated commercially, followed by Alpinia (four species), Kaempferia (two species), and others with one species each cultivated for commercial purposes. Regarding plant parts used for commercial purposes, the majority of cultivated Zingiberaceae species were valued for their rhizomes (42.11%), followed by the whole plant (31.58%) and inflorescences (26.31%). This indicates that the rhizome is the most economically important plant part in the commercial cultivation of Zingiberaceae in the area.

3.2.5. Zingiberaceae Species Used as Cosmetics

In Roi Et Province, five species from the Zingiberaceae family are utilized in cosmetics, with Curcuma species being the most prominent. The species identified for cosmetic use include Curcuma aromatica, C. comosa, C. longa, Wurfbainia schmidtii, and Zingiber montanum (Figure 10). These species are primarily valued for their rhizomes, which are the main part used in cosmetic applications, accounting for 100% of their utilization. Other parts of the plants, such as roots, pseudostems, leaves, inflorescences, fruits, seeds, or the whole plant, are not used in cosmetics in the region. Rhizomes from these Zingiberaceae species are widely incorporated into various cosmetic formulations, particularly for their skin-nourishing properties. The rhizomes of C. aromatica, C. comosa, and C. longa are frequently used in skin care, either fresh or combined with other ingredients such as white clay, honey, lemon juice, cucumber, or milk. The rhizome of W. schmidtii is often boiled and used for steaming or bathing to promote skin nourishment, while Z. montanum rhizomes are processed into powder for exfoliating scrubs. These scrubs are believed to brighten the skin, reduce the appearance of wrinkles and dark spots, protect from free radicals, and prevent acne. The rhizomes are chopped, mixed with white clay, ground into fine powder, and sun-dried, forming a popular skin care treatment in the region.

3.2.6. Zingiberaceae Species Used in Rituals and Beliefs

In Roi Et Province, the use of Zingiberaceae species in rituals and beliefs is highly varied, with differences in the number of species utilized across various genera (Figure 11 and Table 1). Among the 14 genera observed, Curcuma leads with 14 species being utilized, followed by Globba with 8 species and Kaempferia with 5 species. Other genera, such as Amomum and Alpinia, contribute two species each, while Boesenbergia, Hedychium, and Wurfbainia each have one species utilized. Interestingly, genera like Cornukaempferia, Etlingera, Meistera, and Gagnepainia have no species involved in rituals in this region.

The plant parts used in these practices are predominantly the whole plant, accounting for 61.76% of the reported uses. Rhizomes follow closely with 26.48%, while inflorescences are used in 8.82% of cases. Pseudostems are used in a smaller proportion (2.94%), and no plant parts are reported to be used for roots, leaves, or fruits/seeds in these rituals. This distribution underscores the importance of whole plants and rhizomes in the cultural practices of Roi Et Province, particularly within the Curcuma genus.

Most of these species are cultivated with the belief that they can bring about various positive changes in life, such as enhancing good luck, prosperity, and popularity. These plants are deeply embedded in local customs and rituals, where they are believed to play a role in the well-being and success of individuals or communities. The significance of species like Curcuma reflects a wider cultural tradition, where these plants are valued not only for their medicinal or ornamental properties but also for their symbolic role in improving fortune and social standing.

3.2.7. Zingiberaceae Species Used as Herbal Medicine

A total of seven genera of Zingiberaceae plants were used as herbal medicine. Curcuma had the highest species diversity, with 11 species, followed by Zingiber (8 species), Kaempferia (6 species), Alpinia (4 species), Wurfbainia (3 species), Boesenbergia (2 species), and Hedychium (1 species). The most commonly used plant parts for herbal medicine were rhizomes (52.50%), followed by inflorescences (13.75%), leaves (12.50%), pseudostems (7.50%), fruits and seeds (7.50%), and roots (6.25%) (Figure 12).

The use reports of Zingiberaceae plants as herbal medicines were distributed across the following ailment categories (Figure 13): gastrointestinal system (25.32%); infections (16.45%); skin (12.66%); nutrition and blood (10.13%); obstetrics, gynecology, and urinary tract disorders (10.13%); musculoskeletal and joint diseases (8.86%); drugs used in poisoning and toxicology (7.59%); respiratory system (3.80%); cardiovascular system (2.53%); eyes (1.26%); and endocrine system (1.27%).

• Informant Consensus Factor of Zingiberaceae plants in Roi Et Province

The Informant Consensus Factor (F_ic) values for medicinal uses of Zingiberaceae species in Roi Et Province indicate a high level of consensus among informants across various medical categories (

Table 2. Informant Consensus Factor (F_ic) of Zingiberaceae used as medicine founded in Roi Et Province.

Medical Categories	Number of Use Report (nur)	Number of Species (nt)	Fic
Cardiovascular system	48	2	0.98
Drugs used in poisoning and toxicology	294	5	0.99
Endocrine system	18	1	1.00
Eyes	36	1	1.00
Gastrointestinal system	714	19	0.97
Infections	510	12	0.98
Musculoskeletal and joint diseases	160	6	0.97
Nutrition and blood	258	6	0.98
Obstetrics, gynecology, and urinary tract disorders	312	8	0.98
Respiratory system	108	3	0.98
Skin	330	8	0.98

). The highest F_ic values (1.00) were observed in the treatment of endocrine system disorders and eye-related ailments, each involving a single species.

Other categories with strong informant agreement include drugs used in poisoning and toxicology (0.99); infections (0.98); obstetrics, gynecology, and urinary tract disorders (0.98); skin conditions (0.98); respiratory system (0.98); cardiovascular health (0.98); and nutrition and blood health (0.98).

Conditions related to gastrointestinal health (0.97), musculoskeletal and joint diseases (0.97), and the cardiovascular system (0.98) showed slightly lower F_ic values but still reflected substantial agreement among informants.

These findings emphasize the extensive ethnomedicinal knowledge and the significant role of Zingiberaceae species in treating various health conditions. The high F_ic values suggest a strong cultural consensus, underscoring the need for further pharmacological validation to support their therapeutic efficacy in traditional medicine practices.

• Fidelity Level of Zingiberaceae Plants in Roi Et Province

The Fidelity Level (FL) values presented in this study shed light on the consistency with which specific Zingiberaceae plant species are utilized to treat various health conditions in Roi Et Province (Table S5). Higher FL values indicate that a plant is commonly associated with a particular medicinal use, reflecting a strong consensus among informants regarding its application. On the other hand, lower FL values suggest that plants have a more diverse range of uses, reflecting flexibility in their medicinal applications.

Cardiovascular System: The FL values for plants used in cardiovascular health are relatively lower, indicating a broader selection of plants used for these conditions. Boesenbergia rotunda (FL = 36.36) and Zingiber officinale (FL = 16.67) show moderate FL values, suggesting that there are alternative plants with similar medicinal properties used for cardiovascular issues.

Drugs Used in Poisoning and Toxicology: Plants such as Curcuma amarissima (FL = 80.00), Curcuma caesia (FL = 100.00), and Kaempferia angustifolia (FL = 100.00) have strong FL values for treating poisoning and toxicological symptoms, signifying their frequent use for such conditions. These plants are consistently identified for use in toxicological treatments, while others like Curcuma rangjued (FL = 100.00) and Kaempferia marginata (FL = 10.00) show moderate FL values, reflecting some variability in their application.

Endocrine system: One species is used in this category, Zingiber officinale, utilizing the rhizome, with an FL value of 12.50%.

Eyes: One species is used in this category, Kaempferia galanga, utilizing the leaves, with an FL value of 21.43%.

Gastrointestinal System: The FL values for plants in this category are quite varied, indicating a broad range of plants used to address gastrointestinal issues. Boesenbergia xiphostachya (FL = 100.00) and Zingiber ligulatum (FL = 100.00) have the highest FLs, indicating their strong and consistent use for treating gastrointestinal ailments. Other plants like Alpinia conchigera (FL = 62.50) and Curcuma angustifolia (FL = 46.15) also show significant FL values, suggesting that these plants are commonly used for digestive issues, but with some variation in their application compared to those with higher FL values.

Infections: The FL values in this category are more diverse, with plants such as Curcuma aromatica (FL = 100) and Zingiber pyroglossum (FL = 78.57) showing strong fidelity for treating infections. Curcuma amada (FL = 53.85) and Curcuma amarissima (FL = 54.55) also demonstrate significant FL values, indicating that while these plants are frequently used for infections, there are alternative plants in use, as evidenced by the moderate FL values for some species.

Musculoskeletal and Joint Diseases: The FL values in this category indicate that certain plants, such as and Alpinia mutica (FL = 45.45) and Zingiber montanum (FL = 29.63) are commonly used to treat joint pain and related issues. Plants like Curcuma longa (FL = 16.67) and Zingiber mekongense (FL = 16.67) also feature prominently, although their FL values indicate a somewhat broader range of uses, pointing to the flexibility of plant applications for musculoskeletal conditions.

Nutrition and Blood: The FL values for plants used in nutritional and blood-related conditions are also quite varied. For example, Kaempferia parviflora (FL = 100.00) and Curcuma wanenlueanga (FL = 42.86) show moderate to high FL values, indicating their frequent use in promoting nutrition and blood health. However, other plants such as Zingiber zerumbet (FL = 23.33) and Wurfbainia villosa (FL = 35.71) demonstrate more flexibility in their applications, with some informants using them for related but different purposes.

Obstetrics, Gynecology, and Urinary Tract Disorders: Several plants in this category show moderate to high FL values, indicating their strong association with treating reproductive and urinary tract disorders. For example, Hedychium coronarium (FL = 100.00) and Curcuma aeruginosa (FL = 71.43) have high FL values, showing their consistent use in this field. Similarly, Boesenbergia rotunda (FL = 63.64) and Zingiber ottensii (FL = 55.56) are also used for urinary tract and reproductive health, although their FL values suggest slightly more varied uses across informants.

Respiratory System: Three species are used in this category. Alpinia conchigera utilizes the rhizome with an FL value of 37.50%; Kaempferia rotunda utilizes the rhizome with an FL value of 61.54%; and Zingiber officinale utilizes the roots with an FL value of 29.17%.

Skin: The FL values in the skin category vary, showing a wider selection of plants with different uses for skin conditions. Zingiber purpureum (FL = 81.82) is used for external skin treatments, with the former having a high FL indicating its strong and consistent use. Plants like Curcuma longa (FL = 50.00) and Alpinia siamensis (FL = 29.41) have more varied applications for skin, reflected in their lower FL values, highlighting the diversity of treatments available.

3.3. Species Use Value (SUV) of Zingiberaceae in Roi Et Province

The Species Use Value (SUV) for Zingiberaceae species in Roi Et Province reveals considerable variation, reflecting both the cultural and practical importance of these plants. The species with the highest SUVs include Alpinia siamensis with an SUV of 2.505, Zingiber officinale at 2.105, and Alpinia galanga at 2.043. These species, known for their medicinal and culinary applications, dominate the higher end of the spectrum, indicating their widespread use and recognition in the local community. Other notable species with relatively high SUVs are Boesenbergia rotunda (1.933), Curcuma longa (1.863), Curcuma singularis (1.325), and Curcuma angustifolia (1.203), further highlighting the significance of ginger species in local practices.

Several species exhibit considerably lower SUVs, suggesting either limited use or lesser recognition in the region, e.g., Cornukaempferia srisumoniae, Curcuma campanulata, C. saraburiensis, C. ubonensis, C. wanchaii, and Kaempferia sipraiana, all of which have an SUV of 0.005, while Zingiber chrysostachys has an SUV of 0.003. These species, though present in the region, are either used less frequently or are less known.

Finally, two species, Boesenbergia parvula and Meistera chinensis, each exhibit an SUV of 0.000, indicating minimal to no use in Roi Et Province. These species may either have limited ecological or cultural relevance in the area or are largely absent from local practices and applications.

3.4. Genera Use Value of Zingiberaceae in Roi Et Province

The Genera Use Value (GUV) provides a quantitative measure of the relative use and importance of each genus within the Zingiberaceae family in Roi Et Province (

Table 3. Genera Use Value (GUV) of Zingiberaceae plants in Roi Et Province.

No.	Genera	Number of Species	Genera Use Value (GUV)
1.	Alpinia	8	0.651
2.	Amomum	4	0.073
3.	Boesenbergia	3	0.663
4.	Cornukaempferia	2	0.006
5.	Curcuma	33	0.231
6.	Etlingera	1	0.313
7.	Gagnepainia	2	0.039
8.	Globba	10	0.111
9.	Hedychium	1	0.223
10.	Kaempferia	13	0.135
11.	Meistera	1	0.00
12.	Wurfbainia	4	0.085
13.	Zingiber	15	0.243

). Higher GUVs indicate greater utilization, while lower values suggest limited or more specialized uses.

For instance, the genera Boesenbergia (GUV = 0.663) and Alpinia (GUV = 0.651) have the highest GUVs, indicating that these genera are highly utilized in Roi Et Province. These species likely serve a variety of purposes, such as in traditional medicine, ornamental use, or possibly for culinary purposes. In contrast, genera like Cornukaempferia (GUV = 0.006) and Meistera (GUV = 0.00) exhibit minimal to no recorded use, suggesting that these species are less commonly employed in local practices, possibly due to their rarity or less versatile properties.

Curcuma, with its moderate GUV of 0.231, represents a widely used genus in the region, likely for its ornamental value and possible medicinal or culinary applications. Despite having a relatively high number of species (33), the GUV suggests that its usage may not be as widespread or varied as Boesenbergia or Alpinia but still contributes notably to the local Zingiberaceae utilization.

The GUVs reflect the varying levels of practical use and cultural significance of different Zingiberaceae genera in Roi Et Province, highlighting the dominance of certain genera like Boesenbergia and Alpinia in local usage, while others remain of limited or negligible importance.

3.5. Relative Frequency of Citation of Zingiberaceae Plants in Roi Et Province

Relative Frequency of Citation (RFC) values reflect the recognition of Zingiberaceae species in Roi Et Province, with the highest values observed for Alpinia siamensis (RFC = 0.988) and Zingiber officinale (RFC = 0.980). Other species such as Alpinia galanga (RFC = 0.920) and Boesenbergia rotunda (RFC = 0.980) also had relatively high RFC values, showing their widespread recognition in both academic and practical contexts. Species like Curcuma angustifolia (RFC = 0.805), C. mangga (RFC = 0.780), Kaempferia rotunda (RFC = 0.230), and Globba williamsiana (RFC = 0.190) had lower RFC values, indicating that they are less well known or have a more specialized role in the region’s biodiversity [2,3].

The Species Utilization Value (SUV) showed a similar trend, with high RFC species such as Alpinia siamensis (SUV = 2.505) and Zingiber officinale (SUV = 2.105) also demonstrating high practical utilization. However, Curcuma singularis (SUV = 1.325), despite its high RFC, showed lower utilization, indicating that factors like cultural preferences, availability, and specific uses may influence the practical use of a species, even if it is highly recognized (

Table 4. The top 10 Zingiberaceae species utilized in Roi Et Province, ranked according to their RFC value.

Scientific Name	RFC	SUV
Alpinia siamensis K. Schum.	0.988	2.505
Zingiber officinale Roscoe	0.980	2.105
Alpinia galanga (L.) Willd.	0.920	2.043
Boesenbergia rotunda (L.) Mansf.	0.980	1.933
Curcuma longa L.	0.970	1.863
Curcuma singularis Gagnep.	0.988	1.325
Curcuma angustifolia Roxb.	0.805	1.203
Curcuma mangga Valeton and Zijp	0.780	0.935
Kaempferia rotunda L.	0.230	0.445
Globba williamsiana M. F. Newman and Sangvir.	0.190	0.365
Alpinia siamensis K. Schum.	0.988	2.505

).

3.6. Economic Values of Zingiberaceae Plants in Roi Et Province

The results reveal that a wide variety of Zingiberaceae species are commercially cultivated and traded in Roi Et Province, Thailand, with notable variation in plant parts used, price ranges, trading periods, and income generated. Among the 17 listed species (

Table 5. List of Zingiberaceae species cultivated for commercial purposes, including their price ranges, trading periods, monthly sales volume, and average yearly income per trader in Roi Et Province, Thailand.

No.	Scientific Name	Part of Trades	Price (THB/kg)		Trading Periods (Months) 1	Monthly Sales Volume (kg)	Average Yearly Income (THB/Trader)
			Min	Max
1.	Alpinia galanga (L.) Willd.	Inflorescences, Rhizome	35	40	1–12	85	38,250
2.	Alpinia purpurata (Vieill.) K. Schum.	Whole plants	150 *	180 *	1–12	60	118,800
3.	Alpinia siamensis K. Schum.	Inflorescences, Rhizome	35	40	1–12	90	40,500
4.	Alpinia vittata W. Bull	Whole plants	80 *	100 *	1–12	70	75,600
5.	Boesenbergia rotunda (L.) Mansf.	Rhizome	150	100	1–12	100	151,200
6.	Curcuma angustifolia Roxb.	Inflorescences	60	100	6–10	50	20,000
7.	Curcuma comosa Roxb.	Rhizome	180	190	1–12	45	99,900
8.	Curcuma longa L.	Rhizome	50	60	1–12	80	52,800
9.	Curcuma mangga Valeton and Zijp	Rhizome	50	70	1–12	74	53,280
10.	Curcuma singularis Gagnep.	Inflorescences	100	200	4–6	67	30,150
11.	Curcuma wanenlueanga Saensouk, Thomudtha, and Boonma	Rhizome	200	230	1–12	43	110,940
12.	Etlingera elatior (Jack) R. M. Sm.	Whole plants	150 *	280 *	1–12	86	221,880
13.	Globba rosea Gagnep.	Whole plants	80 *	100 *	1–12	40	43,200
14.	Hedychium coronarium J.Koenig	Inflorescences	50	70	6–12	75	27,000
15.	Kaempferia angustifolia Roscoe	Whole plants	50 *	80 *	1–12	40	31,200
16.	Kaempferia elegans Wall.	Whole plants	50 *	100 *	1–12	43	38,700
17.	Zingiber officinale Roscoe	Rhizome	50	70	1–12	85	61,200

¹ The number 1 to 12 represent the months January to December, respectively. * The whole plant price is the price per pot.

), both rhizomes and whole plants are common trading units, with some species also valued for their inflorescences. The highest average yearly income per trader was observed in Etlingera elatior, reaching 221,880 THB, followed by Boesenbergia rotunda and Alpinia purpurata, generating 151,200 THB and 118,800 THB per year, respectively. In contrast, species such as Curcuma angustifolia and Hedychium coronarium yielded lower incomes, with average yearly earnings of 20,000 THB and 27,000 THB, respectively. Most species are traded throughout the year, indicating consistent market demand, although some, such as Curcuma angustifolia, Curcuma singularis, and Hedychium coronarium, are traded only during specific months. The price per unit varied substantially, with whole-plant species such as Etlingera elatior reaching up to 280 THB per pot, while rhizome-based species like Curcuma longa and Zingiber officinale ranged between 50 and 70 THB per kilogram. These findings highlight the economic importance and year-round marketability of several Zingiberaceae species in the region.

3.7. Conservation Status of Zingiberaceae in Roi Et Province

The conservation status of 97 species of Zingiberaceae in Roi Et Province was assessed using data from the IUCN Red List website and our field observations. According to the IUCN, 15 species are listed as Data Deficient (DD), 23 as Least Concern (LC), 56 as Not Evaluated (NE), 2 as Endangered (EN), 1 as Vulnerable (VU), and 1 as Near Threatened (NT).

To enhance regional conservation insight, we proposed conservation status assessments for wild Zingiberaceae species occurring in natural habitats within Roi Et Province based on the IUCN Red List Categories and Criteria, Version 16 (March 2024) (Table 1). These proposals are based on criteria B1 and B2, which consider the extent of occurrence (EOO), area of occupancy (AOO), habitat fragmentation, and observed declines in habitat quality and extent due to anthropogenic pressure, especially from agricultural expansion and land-use changes.

Based on these criteria, Boesenbergia parvula and Kaempferia mahasarakhamensis are proposed as Endangered (EN) under criterion B1 and B2ab (i, ii, iv) due to their highly restricted ranges (EOO < 5000 km² and AOO < 500 km²), observed severe habitat fragmentation, and ongoing declines in habitat extent and quality. Twenty-one species are proposed as Vulnerable (VU) under criterion B2ab (ii, iv, v), including Boesenbergia rotunda, B. xiphostachya, Curcuma campanulata, C. involucrata, C. parviflora, C. singularis, C. thorelii, Gagnepainia harmandii, Globba conferta, G. rosea, Kaempferia galanga, K. isanensis, K. rotunda, K. sakolchaii, K. sakonensis, Zingiber isanense, Z. junceum, Z. mekongense, Z. pyroglossum, Z. rubens, and Z. thorelii. These species are often locally restricted, found in fewer than 10 subpopulations, and experience continuous declines in AOO, habitat quality, or number of mature individuals due to expanding agriculture and seasonal fires.

Thirteen species are proposed as Least Concern (LC), including Alpinia galanga, A. laosensis, A. latilabris, Amomum repoeense, Curcuma angustifolia, Globba marantina, G. sherwoodiana, Kaempferia marginata, Meistera chinensis, Wurfbainia schmidtii, W. uliginosa, W. villosa, and Zingiber zerumbet, as they are widely distributed, occur in both disturbed and undisturbed habitats, and currently face no immediate threats in the province.

These proposed assessments highlight the necessity for continued research to address data gaps and to support conservation planning for species most at risk.

4. Discussion

This study presents a comprehensive assessment of Zingiberaceae diversity in Roi Et Province, documenting 97 species across 13 genera. This notable richness emphasizes the ecological importance of the province within northeastern Thailand, particularly when considered alongside previous regional surveys identifying high species numbers in provinces with diverse topography and land use [2,6,7]. The genus Curcuma, with 33 species recorded, remains the most species-rich in the area—an observation consistent with patterns across Thailand, where Curcuma exhibits substantial diversification in both wild and cultivated environments [3]. The prominence of Zingiber, Kaempferia, and Globba further reflects the ecological plasticity of these genera [2,3].

The discovery of 11 introduced species [1], including widely cultivated taxa such as Curcuma longa and Zingiber officinale, underscores the horticultural and cultural relevance of Zingiberaceae. Meanwhile, the documentation of 86 native species, including 23 endemics to Thailand [1,25,27,41,43,91]—many of which have narrow distributions—highlights the conservation significance of Roi Et as both a biodiversity reservoir and a repository of culturally important plants [24,27]. These findings are consistent with earlier studies suggesting that endemic species within Zingiberaceae often occupy specialized habitats and are thus particularly vulnerable to habitat fragmentation and land-use change [2,3].

A key insight from this study is the differentiation between cultivated and wild occurrences: 61 species were recorded only in cultivation, 36 in the wild, and 3 exclusively in natural habitats. This pattern highlights the integral role of traditional cultivation systems in sustaining plant diversity. Previous ethnobotanical research supports the idea that home gardens and agroforestry systems serve as de facto conservation areas for culturally significant plants [2,3]. However, it is important to recognize potential drawbacks, such as the risk of genetic erosion in cultivated populations, hybridization, and the displacement of wild genotypes. To mitigate these risks, sustainable cultivation practices, such as maintaining wild-type traits, promoting seed exchange networks, and monitoring for genetic integrity, should be integrated into biodiversity conservation strategies.

Conservation status assessments in this study were proposed solely for species found in natural habitats. This approach is based on the rationale that wild populations offer ecologically relevant data for evaluating extinction risk, while cultivated populations often result from human-mediated propagation and may not reflect the status of wild gene pools [1,91]. Cultivated specimens, including Curcuma longa and Zingiber officinale, are frequently exchanged among communities, complicating origin tracing and potentially obscuring the loss of wild populations. This method aligns with IUCN guidelines, which emphasize evaluating naturally occurring populations. Nevertheless, cultivated taxa may still retain genetic diversity and cultural value, warranting further study into their genetic origin and conservation potential.

The Jaccard Similarity and UPGMA cluster analyses provide further ecological insights. High similarity between cultivated habitats and deciduous or dry evergreen forests suggests that traditionally cultivated species are likely derived from these ecosystems—a pattern seen in previous floristic and ethnobotanical studies [2,3]. In contrast, wetlands and mixed deciduous forests formed more distinct clusters, serving as refugia for less commonly cultivated or underutilized species [91]. The robustness of this clustering, supported by a high cophenetic correlation coefficient (0.8755), reinforces the value of conserving diverse habitat types, each supporting a distinct subset of the Zingiberaceae flora.

Phenological data showed that most species began flowering from March to July, peaking in July, with fruiting occurring in August and September. This reproductive synchrony aligns with the monsoon season and reflects a common adaptive strategy among tropical geophytes [3]. However, narrow phenological windows may become increasingly vulnerable under shifting climate regimes. While projections in this study about climate impacts remain speculative, future research should incorporate local climate data and predictive models to better assess how changes in rainfall patterns and temperature fluctuations could disrupt reproductive success [12,92]. Long-term phenological monitoring is needed to support adaptive conservation planning.

From a conservation perspective, these findings stress the need for integrated strategies that encompass both biological and cultural dimensions. Understanding seasonal reproductive cycles can improve field survey timing, conservation prioritization, and propagation efforts. Maintaining habitat heterogeneity—from forests to cultivated areas—will be critical for sustaining the full spectrum of Zingiberaceae diversity in the region.

Ethnobotanical insights affirm the depth of traditional ecological knowledge in Roi Et Province. The extensive use of rhizomes and inflorescences, especially for culinary purposes, reflects the accessibility, organoleptic properties, and cultural significance of these plant parts [3]. The selective use of aromatic and visually appealing species highlights an embedded cultural tradition where utility and aesthetics converge [2,3]. Similar patterns have been observed throughout Thailand and Southeast Asia.

The ornamental appeal of many Zingiberaceae species, particularly those with colorful flowers or variegated leaves, illustrates how cultural aesthetics drive biodiversity conservation. The planting of ornamental gingers around homes and along pathways demonstrates localized habitat management practices where tradition, beauty, and ecological care are intertwined [2,3].

Economically, several species provide year-round income through direct sales or value-added products. The consistent market demand for multipurpose species like Boesenbergia rotunda—found both in the wild and under cultivation—and Etlingera elatior, which occurs only in cultivation in Roi Et, highlights their potential for expanded sustainable horticulture. While E. elatior is not part of the province’s wild flora, overharvesting from cultivated stocks could still pose indirect risks to wild populations in other regions where the species is native. However, in Roi Et, these cultivated species are primarily sourced from managed gardens rather than from natural habitats. Therefore, conservation status assessments in this study were not proposed for species found only in cultivation, due to limited ecological data and the absence of wild populations in the study area. Nonetheless, given the high market demand and potential for unsustainable exploitation in their native ranges, the conservation of these species remains a broader priority beyond the provincial context. Cultivation-focused management, fair benefit-sharing, and regional conservation assessments are recommended to ensure long-term sustainability [37,42].

Medicinal and cosmetic uses of Zingiberaceae remain prominent, especially through the use of rhizomes for their bioactive compounds [93,94]. High Informant Consensus Factor (Fic) values suggest strong cultural consensus and potentially long-standing validation of these uses [88,89]. Species with high Fidelity Levels (%FL) for specific ailments are promising targets for pharmacological and ethnopharmacological studies [86,90].

Spiritual and ceremonial uses further enrich the ethnobotanical landscape. Species with aromatic or colorful traits are often symbolically important, underscoring the link between sensory characteristics and ritual function. Such practices support the continued relevance of Zingiberaceae and promote intergenerational knowledge transmission [3].

Comparative analysis with Kalasin Province shows that Roi Et has higher species diversity (97 species versus Kalasin’s 69), although Kalasin identified 25 new wild taxa and six endemic species, emphasizing its own conservation importance. Kalasin’s species were more evenly distributed across natural and cultivated habitats, whereas Roi Et’s richness was concentrated in cultivated areas. Nevertheless, both provinces demonstrated limited and threatened wild populations.

Ethnobotanically, both provinces revealed the extensive use of Zingiberaceae for food, medicine, ornamentation, and rituals. Roi Et emphasizes diverse use of rhizomes and inflorescences, aligning with Kalasin’s emphasis on rhizomes. Kalasin highlights the high commercial value of Boesenbergia rotunda, a species not singularly emphasized in Roi Et.

In conservation terms, both studies stress the need to protect natural habitats supporting narrowly distributed species. Researchers in Kalasin conducted a detailed IUCN-based assessment, identifying critically endangered and endangered species, while Roi Et, although lacking such detailed categorization, highlights threats to native habitats and emphasizes the vulnerability of taxa restricted to wetlands and dry evergreen forests.

In comparison with Saraburi Province in central Thailand, which recorded 103 species, including 1 novel species and 23 new distribution records, Roi Et’s 97 species and 25 new reports reflect comparable diversity. Saraburi’s more diverse habitats and central location may support broader species ranges. Saraburi also used the District Endemism Index and IUCN criteria to identify conservation priorities, identifying 14 endemic species. Roi Et’s emphasis was on the conservation value of cultivated habitats and endemic taxa like Kaempferia mahasarakhamensis, which are classified as Endangered [1,91].

Despite regional strengths, many species in Roi Et remain unevaluated or listed as Data Deficient, reflecting broader gaps in tropical plant conservation assessments. Habitat degradation, overharvesting, and agricultural expansion continue to threaten local diversity. The low proportion of species categorized as Least Concern suggests that most local taxa have narrow distributions and limited resilience.

Effective conservation strategies must integrate scientific research with community participation. Local monitoring, education programs, and incentive-based conservation can support habitat protection while preserving cultural heritage. Partnerships between researchers, conservation bodies, and local communities are critical for creating ecologically effective and socioeconomically feasible action plans.

Future research should prioritize long-term monitoring of phenology in relation to climate variability to anticipate environmental impacts on reproductive cycles. Genetic and reproductive studies of narrow-range or economically important species will clarify taxonomic boundaries and inform both conservation and sustainable use. Documenting underreported ethnobotanical practices—especially in marginalized communities—could reveal novel applications. Assessing market trends and cultivation feasibility for promising species would also enhance their integration into local agroecological systems. Multidisciplinary research, spanning ecology, taxonomy, ethnobotany, and socioeconomics, will be vital in strengthening conservation and sustainable development in Roi Et and similar tropical regions.

5. Conclusions

This study provides the first comprehensive assessment of Zingiberaceae diversity in Roi Et Province, Thailand, a region that has been poorly documented in terms of both taxonomic and ethnobotanical knowledge. We recorded 97 species, including 86 native and 11 introduced taxa, with 23 species endemics to Thailand, and 25 species newly reported for the province. Species richness was found to be highest in cultivated habitats, indicating the vital role that traditional agroecosystems play in preserving both native and introduced species. This finding aligns with previous ethnobotanical insights that emphasize the deep cultural connection between local communities and Zingiberaceae species, with significant use in food, medicine, ornamentation, and ceremonial practices.

However, our study also highlighted the vulnerability of wild Zingiberaceae populations, particularly those in natural habitats such as wetlands and dry evergreen forests, which support species with restricted distributions. This underscores the critical need for habitat protection and conservation measures that integrate both wild and cultivated populations. Furthermore, our phenological observations, which indicated synchronized flowering and fruiting in line with the monsoon season, suggest that climate change may pose a significant threat to the reproductive success of these species, emphasizing the importance of long-term monitoring to inform conservation planning.

In light of these findings, we advocate for a multipronged conservation approach that includes habitat protection, support for sustainable traditional cultivation practices, and targeted research on economically and culturally valuable species. Community-led monitoring programs, alongside the development of ethnobotanical databases, could enhance local conservation efforts. Moreover, we propose conducting IUCN assessments for unevaluated species to help prioritize conservation actions and safeguard biodiversity. Our study not only highlights the floristic richness of Roi Et Province but also provides actionable steps for integrating traditional knowledge with scientific conservation strategies to ensure the long-term sustainability of Zingiberaceae species in the region.