Thismia, Griffith, 1845

Nuraliev, Maxim S., Yudina, Sophia V., Truong, Ba Vuong, Do, Thi Xuyen, Luu, Hong Truong, Kuznetsov, Andrey N. & Kuznetsova, Svetlana P., 2020, A revision of the family Thismiaceae (Dioscoreales) in Cambodia, Laos and Vietnam, Phytotaxa 441 (3), pp. 229-250 : 233

Key to the species of Thismia in Cambodia, Laos and Vietnam

1. Inner tepals free, with spreading filiform appendages .......................................................................................................................2

- Inner tepals fused apically into mitre, their appendages absent or present ........................................................................................5

2. Inner and outer tepals subequal, both bearing spreading filiform appendages 6.5–20.5(42) mm long; whole flower whitish grey to brown................................................................................................................................................................... Thismia annamensis

- Inner and outer tepals unequal, outer tepals without appendages; flower with white, yellow and/or (orange-)red colours and with yellow or orange annulus....................................................................................................................................................................3

3. Hypanthium inside with transverse bars; hypanthium pale orange outside at least at the upper part; supraconnectives tridentate apically ..................................................................................................................................................................... Thismia javanica

- Hypanthium inside finely irregularly manicate-rugulose without transverse bars; hypanthium often uniformly white outside (but sometimes light orange-red); supraconnectives bidentate or tridentate apically (if tridentate then the hypanthium is uniformly white outside) .....................................................................................................................................................................................4

4. Supraconnectives bidentate apically..................................................................................................................... Thismia tentaculata

- Supraconnectives tridentate apically ..................................................................................................................... Thismia bokorensis

5. Inner tepals imbricately fused within mitre (their overlapping margins visible on outer surface), mitre with narrow central aperture and three long flagelliform appendages; stamens lacking interstaminal glands and skirt-like/wing-like appendages .......................... ........................................................................................................................................................................... Thismia nigricoronata

- Inner tepals valvately fused within mitre (their margins do not overlap), mitre without aperture and conspicuous appendages (only appendages not longer than 2 mm sometimes present); stamens bearing interstaminal glands and skirt-like/wing-like appendages ............................................................................................................................................................................................................6

6. Mitre narrower than hypanthium, bearing three short apical appendages initially appressed into a mucro, with black and glabrous or more or less hairy inner surface ........................................................................................................................ Thismia mucronata

- Mitre broader than hypanthium, lacking apical appendages, with white inner surface covered by papillate trichomes ...................7

7. Flowers large (ca. 3 cm long); annulus vertical, glabrous outside, uniformly white; mitre top with three digitate furrows ............... ................................................................................................................................................................................ Thismia okhaensis

- Flowers small (ca. 2 cm long); annulus dome-shaped with delimited vertical and horizontal parts, covered outside by short hairs, basally white and distally reddish-orange; mitre top with three foveae.................................................................. Thismia puberula