This communication represents an updated checklist of orchid species recorded in Andhra Pradesh, India, based on studies of herbarium specimens, field observations and published literatures. A total of 102 orchid species, including one cultivated species, belonging to 45 genera are enumerated, with detailed annotations dealing with habit, phenology and distribution. The checklist reveals a diverse orchid flora, comprising of 50 epiphytic, 49 terrestrial, and 2 saprophytic species. Habenaria Willd. is the most dominant genus with 16 species, followed by Eulophia R.Br. (09 species), Dendrobium Sw. (07 species), Liparis Rich. and Oberonia Lindl. (05 species each) whereas, Acampe Lindl., Aerides Lour., Bulbophyllum Thouars, Nervilia Comm. ex Gaudich and Peristylus Bleume are represented by 04 species each and the remaining 31 genera are represented by a single species. This checklist contributes to the knowledge of orchid diversity in Andhra Pradesh and provides a reference for further taxonomic and conservation studies.

Andhra Pradesh, Checklist, Conservation, Orchids, Threats.

Orchids (family Orchidaceae) are among the most diverse and ecologically significant plant families, contributing substantially to biodiversity across various ecosystems (Dressler, 1993; Chase et al., 2015; Singh et al., 2019). The family comprises approximately 28,484 species distributed across 850 genera globally (Govaerts et al., 2017). India harbours about 1,256 species belonging to 155 genera, with 307 species being endemic (Singh et al., 2019). Andhra Pradesh, with its varied topography and climatic conditions, supports a rich assemblage of orchid species (Raju et al., 2008; Misra et al., 2008; Pullaiah et al., 2018). Previous floristic studies have revealed several species from this region; however, an updated checklist incorporating recent findings from published literatures (Kothareddy et al., 2019; Venkaiah et al., 2020; Kumar et al., 2022; Rao et al., 2024), herbarium collections and field observations is the need of the hour.

A. Study Area

Andhra Pradesh, a state located in the south-eastern part of the Indian subcontinent, lies between 12°41' to 19°07'N latitude and 77° to 84°40'E longitude. It shares borders with Tamil Nadu, Karnataka, Telangana and Odisha, and is bounded to the east by a 970 km coastline along the Bay of Bengal. The state covers an area of 162,975 km2, divided into 26 districts (Fig. 1). The state is notable for its significant biodiversity, particularly within the Eastern Ghats. This region extends from the Koundinya Wildlife Sanctuary in Chittoor district to the Palakonda Reserve Forest in Parvathipuram Manyam district. The Eastern Ghats feature diverse hill ranges, including the Araku, Papikonda, Nallamala and Seshachalam hills, which support a rich variety of flora and fauna. These discontinuous and varied hill masses generally trend northeast-southwest along the Bay of Bengal. Andhra Pradesh, characterized by the Eastern Ghats and the Krishna and Godavari River deltas, possesses a rich botanical heritage with a forest cover of 18.46%. Its diverse vegetation, primarily found in the Eastern Ghats, is classified into seven major forest types according to Champion and Seth's 1968 classification. These range from Tropical Semi-Evergreen and Moist Deciduous Forests in wetter, higher elevation areas to Dry Deciduous, Savanna, Evergreen, and Scrub Forests in drier and lower regions, reflecting the state's varied climate, topography, and soil conditions.

Fig. 1. District map of Andhra Pradesh.

Botanical exploration in Andhra Pradesh has a long history spanning over centuries, marked by foundational works such as Roxburgh's "Plants of the Coromandel Coast" and Wight's extensive documentation, followed by significant contributions from botanists including Beddome, Gamble and Fischer, culminating in landmark floras. The 20th century saw continued research by various scientists and the Botanical Survey of India, leading to comprehensive works that detailed the region's plant diversity. Pullaiah et al. (2018) reported 2880 species including 93 orchid taxa, reflecting the significant progress in understanding Andhra Pradesh’s flora. However, comprehensive documentation of the orchid diversity in this region has been limited. This study aims to provide an updated annotated checklist of orchids dwelling in Andhra Pradesh, based on a thorough review of available data.

B. Data Collection and Analysis

This checklist was compiled through a comprehensive review of existing data sources. The following methods were employed:

∙ Herbarium Collections: Specimens housed in regional and national herbaria were examined to verify species identification and distribution records.

∙ Field Observations: Field surveys were conducted across various habitats in Andhra Pradesh to document orchid occurrences and collect detailed information on their phenology (flowering and fruiting periods) and habit (terrestrial or epiphytic).

∙ Research Publications: A thorough review of published literatures, including floristic surveys, taxonomic revisions, and regional floras, was undertaken to compile a comprehensive list of orchid species reported from the state (Pullaiah et al., 2018; Kothareddy et al., 2019; Venkaiah et al., 2020; Kumar et al., 2022; Prasad, 2022a & 2022b; Rao et al., 2024).

Species identification was based on established taxonomic literature and expert consultation (Singh et al., 2019; Agarwala et al., 2023). The nomenclature of the species was updated in accordance with the International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code) (Turland et al., 2018; POWO, 2024). The resulting checklist includes the scientific name of each species, its habit (terrestrial or epiphytic), the observed flowering and fruiting period, and its documented occurrence within Andhra Pradesh.

The present study enumerated 102 orchid species, including one cultivated species, belonging to 45 genera in Andhra Pradesh (Table 1). The orchid flora exhibited a mix of habits: epiphytic (50 species), terrestrial (49 species), and saprophytic (2 species), reflecting the diverse habitats present in the state (Fig. 2). Habenaria Willd. is the most dominant genus with 16 species, followed by Eulophia R.Br. with 09 species and Dendrobium Sw. with 07 species. Liparis Rich. and Oberonia Lindl. are represented by 05 species each; Acampe Lindl., Aerides Lour., Bulbophyllum Thouars, Nervilia Comm. ex Gaudich and Peristylus Bleume by 04 species each, while the remaining 31 genera are represented by a single species (Fig. 3). This dominance aligns with general trends observed in other tropical and subtropical regions of India, where these genera are frequently well-represented.     

Visakhapatnam, East Godavari, and Chittoor districts emerge as dominant regions for orchid diversity, hosting a wide array of species adapted to various habitats. Visakhapatnam stands out with species such as Acampe carinata (Griff.) Panigrahi, Aerides odorata Lour., Bulbophyllum sterile (Lam.) Suresh, Coelogyne imbricata (Hook.) Rchb.f., and Dendrobium regium Prain, thriving as epiphytes and terrestrials. East Godavari follows closely, supporting Acampe praemorsa (Roxb.) Blatt. & McCann, Cymbidium aloifolium (L.) Sw., Dendrobium aphyllum (Roxb.) C.E.C. Fisch. and Eulophia recurva (Roxb.) M.W.Chase, Kumar & Schuit., among others. Chittoor is also endowed with significant orchid diversity including Bulbophyllum kaitiense Rchb.f., Habenaria longicornu Lindl., and Vanda tessellata (Roxb.) Hook. ex G.Don, showcasing the region's rich ecological conditions. The orchid flora in these districts not only highlights their unique biodiversity but also underscores their importance in conservation efforts.

Fig. 2. Habit wise Orchids of Andhra Pradesh.

Fig. 3. Dominant genera of Orchids of Andhra Pradesh.

Table 1: List of Orchid species occurring in Andhra Pradesh State.

Certain orchid species are known to have a restricted distribution, occurring only in a single district. These species are highly localized and require conservation efforts to ensure their survival. Below is a list of orchid species that are found exclusively in a single district:

∙ Acampe carinata (Griff.) Panigrahi - Visakhapatnam

∙ Acampe ochracea (Lindl.) Hochr. - Visakhapatnam

∙ Acanthophippium bicolor Lindl. - Visakhapatnam

∙ Aerides maculosa Lindl. - Kurnool

∙ Aphyllorchis montana Rchb.f. - Chittoor

∙ Bambuseria bambusifolia (Lindl.) Schuit., Y.P.Ng & H.A.Pedersen - Visakhapatnam

∙ Bulbophyllum cariniflorum Rchb. f. - Visakhapatnam

∙ Bulbophyllum sterile (Lam.) Suresh - Visakhapatnam

∙ Bulbophyllum umbellatum Lindl. - Visakhapatnam

∙ Corymborkis veratrifolia (Rieinw.) Blume - YSR District (Kadapa)

∙ Dendrobium regium Prain - Visakhapatnam

∙ Didymoplexis pallens Griff - West Godavari

∙ Epipogium roseum (D.Don) Lindl. - Alluri Sitharama Raju

∙ Eulophia diffusiflora M.W.Chase, Kumar & Schuit. – Kurnool

∙ Habenaria brachyphylla (Lindl.) Aitch. - Visakhapatnam

∙ Habenaria diphylla (Nimmo) Dalzell - Visakhapatnam

∙ Habenaria grandifloriformis Blatt & McCann - Visakhapatnam

∙ Habenaria longicorniculata J.Graham - Visakhapatnam

∙ Habenaria rariflora A. Rich. - Chittoor

∙ Liparis elliptica Wight - Visakhapatnam

∙ Nervilia infundibulifolia Blatt. & Mccann - Visakhapatnam

∙ Pelatantheria insectifera (Rchb.f.) Ridl. - Visakhapatnam

∙ Peristylus parishii Rchb.f. - Kurnool

∙ Phalaenopsis deliciosa Rchb.f. - Visakhapatnam

∙ Polystachya concreta - Visakhapatnam

∙ Pomatocalpa spicatum Breda - Visakhapatnam

∙ Satyrium nepalense D. Don - Visakhapatnam

∙ Sirhookera latifolia (Wight) Kuntze - Visakhapatnam

∙ Spiranthes sinensis (Pers.) Ames - Visakhapatnam

∙ Thunia alba var. bracteata (Roxb.) N.Pearce & P.J.Cribb - Visakhapatnam

∙ Tropidia angulosa (Lindl.) Blume - East Godavari

∙ Vanilla walkerae Wight - Chittoor

∙ Zeuxine strateumatica (L.) Schltr. - Anantapur

These species are particularly vulnerable due to their limited geographic range. Protecting their natural habitats is essential to maintaining their ecological presence and ensuring their survival for future generations.

Plate 1. A. Aerides odorata Lour.; B. Bulbophyllum umbellatum Lindl.; C. Coelogyne imbricata (Hook.) Rchb.f.; D. Cottonia peduncularis (Lindl.) Rchb.f..; E. Dendrobium aqueum Lindl.; F. Dendrobium regium Prain; G. Didymoplexis pallens Griff.

Plate 2. A. Bambuseria bambusifolia (Lindl.) Schuit.; B. Eulophia recurva (Roxb.) M.W.Chase, Kumar & Schuit.; C. Habenaria brachyphylla (Lindl.) Aitch.; D. Pecteilis gigantea (Sm.) Raf; E. Habenaria malintana (Blanco) Merr.; F. Phalaenopsis deliciosa Rchb.f.