Tripogon bimucronatus Thoiba & Sunil, Gard. Bull.

K., Thoiba, Abstract, A. K. Pradeep & Roem., Tripogon, 2020, A revision of Tripogon (Poaceae: Chloridoideae) in India, Rheedea 30 (3), pp. 325-378 : 332-333

Tripogon bimucronatus Thoiba & Sunil, Gard. Bull. Singapore 67(1): 151. 2015. Type: INDIA , Kerala, Palakkad district, Nelliyampathy hill top, 1200 m, 16.11.2010, C.N. Sunil 4477 (holo SING!; iso BRIT!, CAL!, CALI [ CALI112088 !], K).

FiGS. 5 & 8

Tufted perennials. Culms 30–60 cm high, erect; nodes glabrous. Leaf sheaths closely involute to the culm, rigid, sparsely hairy; ligules ciliate, 2–2.5 mm long; leaf blades 30–60 × 0.4–0.6 cm, linear, hispid towards base, scabrid adaxially, margins involute, apex acute-acuminate. Racemes 30–40 cm long, rigid, straight or slightly curved, 45–65 spikelets tightly appressed to concavities in rachis; rachis stout, minutely scaberulous, triangular; peduncles 10–15 cm long, glabrous, terete. Spikelets 1.3–1.8 × 0.2–0.25 cm, linear-lanceolate, 6–8-flowered; callus bearded; rachilla not persistent, hidden, 1–2 mm long, slightly scabrid; lower glumes 3–3.5 × c. 1 mm, lanceolate, asymmetrical, notched on one-side below the middle, chartaceous, 1-nerved, acute-acuminate at apex; upper glumes 5–6 × c. 1 mm, elliptic-lanceolate, prominently 3-nerved, glabrous, apex mucronate or shortly awned, awns 0.5–1 mm long; lemmas 5–5.5 × 1.5–2 mm (excluding awn), 3-nerved, 1-awned, awn arising between lateral lobes, median awn 5–5.5 mm long, scabrid, straight or geniculate, lateral awns absent; paleas 4–5 × 1–2 mm, hyaline, narrowly elliptic, keeled, winged, keels minutely puberulous, apex bi-mucronate, notched at centre; lodicules 2, c. 0.25 mm long, quadrate, apex coarsely 3-toothed; stamens 3, anthers 1–1.5 mm long, oblong, filaments 0.5–0.75 mm long, slender, glabrous; ovary 0.25–0.5 mm long, obovate, styles 2, 1 mm long, slender, hyaline, stigma 1–1.5 mm long. Caryopses 1.1–1.3 × 0.4–0.5 mm, narrowly oblong-lanceolate, obtusely trigonous, longitudinally ribbed abaxially, pale brown, obtuse at apex.

Flowering & fruiting: Flowering and fruiting from September to November.

Habitat: It usually grows on granitic grassy slopes at elevations between 1000–1200 m, in association with Cyanotis papilionacea (Burm.f.) Schult. & Schult.f. ( Commelinaceae ), Arthraxon castratus Bor , Chrysopogon nodulibarbis (Hochst.) Henrard , Cymbopogon commutatus Stapf , Eulalia trispicata (Schult.) Henrard , Garnotia elata Janowsky , Isachne bourneorum C.E.C.Fisch. and Tripogon wightii (all Poaceae ), Osbeckia spp. ( Melastomataceae ), Sopubia trifida D.Don ( Scrophulariaceae ), Swertia angustifolia D.Don. ( Gentianaceae ) and Tephrosia pulchella Hook.f. ( Fabaceae ).

Distribution: Endemic to South India .

Specimens examined: INDIA , Kerala, Idukki district, Meenuliyanpara, Vannappuram , 28.11.2014, C. N . Sunil 4910 ( SNM College Herbarium, Kerala); Ibid., 20.12.2016, F . Dani s.n. ( CALI) .

Notes: Tripogon bimucronatus is similar to T. vellarianus but differs by its asymmetrical lower glumes, mucronate or shortly awned upper glumes and bi-mucronate paleas.

Figures

FiG. 5. Tripogon bimuCronatus Thoiba & Sunil: a. Habit; b. Spikelet; c. Lower glume; d. Upper glume; e. Lemma; f. Palea; G. Enlarged portion of palea apex; h. Pistil; i. LodiCule; j. Stamen; k. 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].