Gastrodia, R. Brown, 1810

Khanal, Madhusudhan, Sarkar, Shuvadip, Sarkar, Kingsuk, Chhetri, Prakash, Rai, Santosh Kumar, Kumar, Devendra & Rawat, Sandeep, 2024, Gastrodia indica (Orchidaceae: Gastrodieae), a new completely cleistogamous holomycotrophic species from India, Phytotaxa 663 (1), pp. 26-32 : 30

Key to species of Gastrodia in India

1. Plants with chasmogamous flowers....................................................................................................................................................2

-. Plants with complete cleistogamous flowers......................................................................................................................... G. indica

2. No of flowers less than 10 ..................................................................................................................................................................8

-. No of flowers more than 10................................................................................................................................................................3

3. Disc callose.........................................................................................................................................................................................4

-. Disc ecallose..................................................................................................................................................................... G. falconeri

4. Labellum trilobed ...............................................................................................................................................................................5

-. Labellum simple .................................................................................................................................................................................7

5. Disc with two median parallel, vertical lamellae ......................................................................................................... G. mishmensis

-. Disc papillose without any median parallel lamellae .........................................................................................................................8

6. Plants comparatively taller (30–200 cm); floral bracts acuminate.......................................................................................... G. elata

-. Plants relatively shorter (25–60 cm); floral bracts acute........................................................................................ G. arunachalensis

7. Disc with 4 longitudinal lamellae; 2 globose calli present at base.................................................................................... G. dyeriana

-. Disc with 2 wing-like obtuse longitudinal lamellae; 2 reniform calli present at base ........................................................... G. exilis

8. Rhizome glabrous; perianth surface without striations, perianth tube opening comparatively wider at apex...................................9

-. Rhizome densely pubescent, with scattered tiny scales; perianth surface distinctly striated on the outer surface, perianth tube opening only through a narrow perforation at apex ...................................................................................................... G. sikkimensis

9. Stem up to 4 cm tall; labellum deltoid, acuminate at the apex and clawed at the base with pair of ovoid calli, disc without any callus, epichile curved upward with a tongue-like thickening; column broadly winged at apex with anterior ends inwardly folded............ ................................................................................................................................................................................. G. silentvalleyana

-. Stem up to 11 cm tall; labellum oblong-lanceolate, apex slightly canaliculate, obtuse to acute, base with 2 verrucose ovoid calli, disc with 3 longitudinal calli; column narrowly winged along its length ............................................................................ G. bambu