Tripogon, Roemer & Schultes, 1817

Chorghe, Alok, Rasingam, L., Prasanna, P. V. & Rao, M. Sankara, 2013, Tripogon tirumalae (Poaceae), a new species from the Seshachalam hills of Andhra Pradesh, India, Phytotaxa 131 (1), pp. 17-22 : 20-21

Key to the species of Tripogon in India

1. Lowest lemma empty, dissimilar to other lemmas ................................................................ T. wardii Bor (1957: 417)

- Lowest lemma bisexual, similar to all the other lemmas.............................................................................................. 2

2. Culms up to 10 cm high; leaf blades 1–2 cm long, rigid, convolute, pungent at apex ................................................... ...................................................................................................................................... T. pungens Fischer (1934: 170)

- Culms above 10 cm high; leaf blades above 2.5 cm long, acuminate to attenuate and not pungent............................ 3

3. Lemmas cleft at apex into 4 or 6 lobes or with a definite lobes between each lateral awn and the median; outer lobes, if present awned or not................................................................................................................................................. 4

- Lemmas cleft at apex into 2 lobes, awned in the cleft; lobes awned or not ................................................................. 9

4. Lemmas cleft at apex into 6 lobes ................................................................................................................................ 5

- Lemma cleft at apex into 4 lobes .................................................................................................................................. 6

5. Upper glumes 7–9 mm long, notched at apex with small awn between; keels of paleas ciliate; stamens 1.3–2 mm long ................................................................................................. T. anantaswamianus Sreekumar et al. (1985: 185)

- Upper glumes 3 mm long, acute at apex, deeply 2-lobed with arista 0.5 mm long; keels of paleas not ciliate; stamens up to 0.8 mm .............................................................................................................. T. borii Kabeer et al. (2009: 115)

6. Median awn twice as long as the lemma or more; very slender grass; upper glumes 2-toothed below the apex .......... ....................................................................................................................... T. filiformis Nees ex Steudel (1854: 301)

- Median awn shorter than or nearly equal to the lemma; stout grass; upper glumes 2-fid ............................................ 7

7. Leaves hairy; ligules inconspicuous; keels of paleas scabrid ........................................ T. bromoides Roth (1817: 600)

- Leaves glabrous or hairy; ligules conspicuous, thin, membranous; keels of the paleas ciliate .................................... 8

8. Culms 10–20 cm high; lower glumes shallowly lobed on one-side above the middle; central lobes of the lemmas ovate–acute.................................................................................................. T. narayanae Sreekumar et al. (1983: 196)

- Culms 24–70 cm high; lower glumes deeply lobed on one-side below the middle; central lobes of the lemmas lanceolate................................................................................................................ T. ravianus Sunil & Pradeep (2001: 803)

9. Median awn shorter than the lemma, occasionally almost absent .............................................................................. 10

- Median awn as long as or longer than the lemma.......................................................................................................14

10. Perennials with roots forming tufts; leaf blades glabrous........................................................................................... 11

- Perennials with fibrous roots, forming close turf; leaf blades covered with mass of matted white hairs .................. 13

11. Leaves and culms glaucous; leaf blades involute, filiform; ligules very short and ciliate ............................................. .................................................................................................................................... T. jacquemontii Stapf (1892: 85) - Leaves and culms green, not glaucous; leaf blades usually flat, sometimes rolled; ligules obsolete......................... 12

12. Leaf blades 3–6 mm wide; racemes 7–25 cm long, median awn shorter than lemmas ....... T. lisboae Stapf (1892: 84)

- Leaf blades 8–15 mm wide; racemes 30–40 cm long, median awn longer than lemmas............................................... ......................................................................................................................... T. vellarianus A.K. Pradeep (1999: 811)

13. Culms up to 10 cm tall; spikelets 2–3–flowered; lemmas up to 3 mm long .................................................................. ................................................................................................................................ T. purpurascens Duthie (1901: 74)

- Culms up to 45 cm tall; spikelets 4–5–flowered; lemmas 3.5–4.5 mm long.................................................................. ...................................................................................................................................... T. hookerianus Bor (1960: 522)

14. Median awns flexuous, capillary, several times as long as lemma................................................................................. ...................................................................................................................... T. capillatus Jaubert & Spach (1851: 47)

- Median awns straight or curved, not more than twice as long as the lemma ............................................................. 15

15. Spikelets 1–4 cm long; paleas broadly winged........................................................................................................... 16

- Spikelets not more than 1 cm long; paleas narrowly winged ..................................................................................... 18

16. Annuals ................................................................................................................ T. cope Newmaster et al. (2008: 698)

- Perennials.................................................................................................................................................................... 17

17. Upper glumes 5.5–7 mm long; awns of the lemmas 6–8 mm long ................................................................................ ........................................................................................................................................ T. wightii Hooker (1896: 286)

- Upper glumes 8–9.5 mm long; awns of the lemmas 10.5–12 mm long ......................................................................... ................................................................................... T. velliangiriensis Murugesan & Balasubramaniam (2008: 109)

18. Culms 20–45 cm long; summit of leaf sheaths densely hairy; lemma 2–lobed, the lobes awned at apex, median awn more than twice as long as the lemma ............................................................................ T. trifidus Hooker (1896: 286)

- Culms 40–75 cm high; summit of leaf sheaths glabrous; lemma 2–lobed, apex acuminate, median awn less than or more than lemma......................................................................................................................................................... 19

19. Ligules membranous; lemma base glabrous, median awn as long as or shorter than the lemma; inflorescence 20–45 cm long; spikelets with 5–8 florets ............................................................................... T. sivarajanii Sunil (1999: 809)

- Ligules ciliate, membranous; lemma base bearded, median awn 1.5 times longer than lemma; inflorescence 15–20 cm long; spikelets with 9–10 florets ........................................................................................................... T. tirumalae