Tripogon borii Kabeer, V.J.Nair & G.V.S.Murthy, Bull. Bot. Surv.

K., Thoiba, Abstract, A. K. Pradeep & Roem., Tripogon, 2020, A revision of Tripogon (Poaceae: Chloridoideae) in India, Rheedea 30 (3), pp. 325-378 : 333-335

Tripogon borii Kabeer, V.J.Nair & G.V.S.Murthy, Bull. Bot. Surv. India 50(1–4): 115. 2009. Type: INDIA , Tamil Nadu, Kanyakumari district, Nagerkoil, Maruthwamala, ± 360 m, 30.11.2005, K. Althaf Ahamed Kabeer 118632 (holo CAL; iso MH [MH00003227!]). FiGS. 6–8

Caespitose perennials. Culms up to 60 cm high, terete; nodes glabrous, slightly geniculate. Leaf sheaths 5–10 cm long, linear, glabrous or hairy, apex densely ciliate; ligules membranous, with a tuft of 1–2.5 mm long hairs at apex; leaf blades 25–47 × 0.2–0.4 mm, linear, flat-involute, nerves prominent, adaxially glabrous to sparsely long hairy, abaxially finely scabrellate along ribs, attenuate at apex. Racemes 15–28 cm long, stiff, straight to curved, spikelets appressed to concavities in rachis; rachis stout, glabrous, ribbed; peduncles 5–14 cm long, terete, glabrous. Spikelets 10–16 × 1–2 mm, ovate-lanceolate, linear, creamy, 6–14-flowered; callus bearded, hairs 0.5–1 mm long; rachilla up to 0.7 mm long, oblique at apex; lower glumes 1.8–2.3 × 0.5–0.8 mm, oblong, deeply lobed below middle along one side, lobes acute to acuminate, 1-nerved, 1-keeled, keels slightly scabrid, acute and mucronulate at apex; upper glumes 2.3–4 × c. 0.8 mm, elliptic-oblong, 1-keeled, 1-nerved, apex bi-lobed, aristate, arista 0.5–2 mm long at sinus; lemmas 2.8–4 × 0.8–1 mm (excluding awn), oblong-lanceolate, 6-lobed, 3-nerved, 3-awned, median awns 2.5–3.5 mm long; lobes on either side of median awns acute to acuminate, 0.4–1 mm long, lateral awns 1.5–2.5 mm long, lateral lobes on either side conspicuous, slightly keeled; paleas 2.3–2.8 × 0.8–1 mm, oblong-elliptic, hyaline, 2-nerved, 2-keeled, keels ciliate, sub-acute at apex; lodicules 2, 0.3–0.5 mm long, truncate; stamens 3, anthers 0.7–1 mm long, oblong, purple tinged at fresh, filaments 0.5–0.75 mm long, slender, glabrous; ovary 0.3–0.4 mm, oblong-elliptic, styles 2, 1–1.2 mm long, slender, hyaline, stigma 0.7–1 mm long, plumose, creamy white. Caryopses 1.5–1.8 × 0.2– 0.3 mm, narrowly oblong-lanceolate, light brown.

Flowering & fruiting: Flowering and fruiting from September to early December.

Habitat: This species prefers to grow in rock crevices and on seasonally wet bare rocks in high elevation grasslands in association with Anisochilus carnosus (L.f.) Wall., Leucas nepetifolia Benth. (both Lamiaceae ), Cyanotis cristata (L.) D.Don ( Commelinaceae ), Arundinella pumila Steud. , Cymbopogon citratus Stapf , Eragrostiella bifaria (Vahl) Bor , Tripogon bromoides (all Poaceae ), Henckelia incana (Vahl) Spreng. ( Gesneriaceae ) and Justicia sp. ( Acanthaceae ).

Distribution: Endemic to South India .

Specimens examined: INDIA , Tamil Nadu, Coimbatore district, Velliangiri hills, 30.09.2016, A. K . Pradeep, Nikhil Krishna & K . Thoiba 146727; Ibid. , 30.09.2016, A. K . Pradeep, Nikhil Krishna & K . Thoiba 146728, 146729 ( CALI); Kanyakumari district , Maruthwamala, 09.08.2014, K . Thoiba 138094; Ibid. , 30.10.2015, K . Thoiba & T . Mohammed Yoonus 146650, 146658, 146660, 146662, 146665 ( CALI); Nagercoil, Mambazhathuraiyar reservoir, 29.10.2015, K . Thoiba & T . Mohammed Yoonus 146648 (CALI).

Notes: Very similar to Tripogon zeylanicus and T. bromoides , but differs in having ovate-lanceolate, creamy yellow spikelets with up to 14 florets and lower glumes being deeply lobed below the middle along one-side; upper glumes bi-lobed at apex and 0.5–2 mm long arista at the sinus.

Tripogon bromoides Roem. & Schult., Syst. Veg. 2: 600. 1817; Hook.f., Fl. Brit. India 7(22): 287. 1896; C.E.C.Fisch. in Gamble, Fl. Madras 3: 1834. 1934; Bor, Grass. Burma Ceylon India & Pakistan 521. 1960; Britto & K.M.Matthew in K.M.Matthew, Fl. Tamilnadu Carnatic 3(2): 1911. 1983; Karth., S.K.Jain, M.P.Nayar & Sanjappa, Fl. Ind. Enum. Monocot. 622. 1989; Sreek. & V.J.Nair, Fl. Kerala Grass: 399. 1991; M.D.Dassanayake, F.R.Fosberg & W.D.Clayton, Revis. Handb. Fl. Ceylon 8: 443. 1994; S.Moulik, Grass. Bam. India 2: 622. 1997; Pull., Fl. Andhra Pradesh 3: 1268. 1997; Sasidh., Biodiv. Doc. Kerala –Fl. Pl.: 595. 2004; Kabeer & V.J.Nair, Fl. Tamil Nadu Grass. 179. 2009; Potdar, Salunkhe & S.R.Yadav, Grass. Maharashtra: 557. 2012. Avena mysorensis Spreng. Syst. Veg. 1: 337. 1825. Type: INDIA , Karnataka, Mysore, 1814, B. Heyne s.n. (B [B10367364 digital image!]).

Notes: Bor (1960) considered T. bromoides as an “extremely variable grass” and commented on the varieties recognised by Hooker (1896) as “hardly worth keeping”. However, the present investigation based on a large number of specimens from its entire range of distribution revealed that one of his varieties ( var. longifolius Hook.f. ) is worth keeping.

Figures

FiG. 6. T.borii Kabeer,V.J.Nair & G.V.S.Murthy in its natural habitat at Maruthwamala in Kanyakumari distriCt. (Photo by K. Thoiba).

FiG. 7. Tripogon borii Kabeer, V.J.Nair & G.V.S.Murthy: a. Habit; b. Spikelet; c. Lower glume; d. Upper glume; e. Lemma; f. Palea; G. LodiCule; h. Pistil; i. Stamen; j. Caryopsis.

FiG. 8. Distribution of Tripogon bimuCronatus Thoiba & Sunil and T. borii Kabeer,V.J.Nair & G.V.S.Murthy in India [drawn using ESRI (2011) ArCGIS Desktop: Release 10].