Thismia, Griff., Griff.

KEY TO THE MALAYSIAN SPECIES Of THISMIA View in CoL

1. Inner perianth lobes free, spreading or erect. Underground part vermiform, creeping.................................................... 2

2. Perianth lobes equal in length and size......................................................................................... 3

3. Flowers zygomorphic, geniculate............................................................................. T. chrysops Ridl. View in CoL

3. Flowers actinomorphic................................................................................................... 4

4. Stems several, flowers 4–6 in a raceme..................................................................... T. racemosa Ridl. View in CoL

4. Stem simple; flowers usually 1–3, terminal............................................................................... 5

5. Leaves and bracts beset with distinct, prominent, blunt processes........................................ T. grandiflora Ridl. View in CoL

5. Leaves and bracts without processes................................................................................ 6

6. Perianth lobes lanceolate, acute to acuminate, flat....................................................... T. fumida Ridl.

6. Perianth lobes triangular at the base, tapering into long, filiform tentacles............................................. 7

7. Stigmas bifid.............................................................................................. 8

8. Transverse bars found throughout the perianth tube inside. Anther appendages 2............................... 9

9. Perianth white with 12 brownish purple streaks; lobes with tentacles ca. 17 mm ......................................... T. mullerensis Tsukaya & H. Okada

9. Perianth white with 12 white streaks; lobes with tentacles ca. 70 mm .......................... T. lauriana Jarvie

8. Transverse bars found only in the basal part of the perianth tube. Anther appendages 3............ T. bifida M. Hotta

7. Stigmas not bifid......................................................................................... 10

10. Perianth tube with horizontal bars inside. Stigmas lanceolate............................................... 11

11. Anthers provided with 3 thick-filiform appendages at the free apical margin. Perianth yellowish in the basal part, bright orange-yellow in the upper part and limb. Tentacles bright orange-red at the base. Perianth lobes with tentacles up to 10 mm ............ T. aseroe Becc.

11. Anthers with 1 thick-filiform, median appendage and 2 lateral, short teeth at the free apical margin. Perianth white with 6 ochre-brown streaks; lobes with tentacles ca. 20 mm ............................................... T. alba Holttum ex Jonker

10. Perianth tube without bars. Apical margin of the anthers with 2 teeth, each bearing a globose body at the top. Stigmas funnel-shaped with prominent margin........... T. ophiuris Becc.

2. Inner perianth lobes larger................................................................................................... 12

12. Perianth zygomorphic, bilabiate. Upper lip fleshy, bent over the opening of the tube................................. T. labiata J. J. Sm.

12. Flowers actinomorphic.................................................................................................. 13

13. Inner perianth lobes simple. Tube with prominent horizontal bars inside................................................... 14

14. Anthers with 3 distinct teeth at the free apical margin, each tooth bearing a stiff hair. Outer perianth lobes broadly ovate, obtuse, erect................................................... T. javanica J. J. Sm.

14. Anthers slightly dentate apically. Outer perianth lobes short, ear-shaped................................. T. arachnites Ridl.

13. Inner perianth lobes consisting of 3 parts. Basal part erect, short, bearing the transverse part, hamate at the base and broadened at the apex. Third part awl-shaped, inserted on the broad apex of the second part. Perianth tube without bars.................................... T. neptunis Becc.

1. Inner perianth lobes connected at the apex to an erect mitre with 3 holes.............................................................. 15

15. Under ground part vermilliform............................................................................................ 16

16. Mitre broader than perianth tube, annulus erect.......................................................... T. mirabilis K. Larsen

16. Mitre narrower than perianth tube, annulus curved................................................. T. angustimitra Chantanaorr.

15. Underground part coralliform.............................................................................................. 17

17. Inner perianth lobes connate at the tips, forming an erect mitre with large holes............................................... 18

18. The mitre lacks clavate segments................................................................................... 19

19. Inner perianth lobes linear. Anthers ciliate in the basal part, toothed at the apex...................................... 20

20. Apical margin of the anthers provided with 2 teeth, each bearing a stiff hair. Anthers slightly constricted in the middle, below the thecae............................ T. clandestina (Blume) Miq.

20. Apical margin of the anthers provided with 3 teeth, each bearing a stiff hair. Anthers constricted at the base, just above the thecae................................ T. episcopalis (Becc.) F. Muell.

19. Inner perianth lobes spathulate, connate to a mitre with rather small holes. Anthers not ciliate, truncate at the apex..................................................... T. crocea (Becc.) J. J. Sm.

18. Inner perianth lobes continued above the mitre as 3 free, almost erect, filiform, clavate segments............................ 21

21. Flowers yellow-orange to pink-red, three hood-shaped appendices on the mitre are not or only poorly developed, wing of the anther connectives has an unequal margin and is acute at the apex, bearing round, nectariferous glands.................................. T. clavigera (Becc.) F. Muell.

21. Flowers blue-green, three hood-shaped appendices on the mitre are conspicuous, the margin of the anther connectives is equal in shape and lacks an acute, elongated apex, bearing rectangular, long glands............................ T. betung-kerihunensis Tsukaya & H. Okada