Tripogon idukkianus Sunil & Pradeep, Phytotaxa

K., Thoiba, Abstract, A. K. Pradeep & Roem., Tripogon, 2020, A revision of Tripogon (Poaceae: Chloridoideae) in India, Rheedea 30 (3), pp. 325-378 : 344-345

Tripogon idukkianus Sunil & Pradeep, Phytotaxa 202(4): 295. 2015 . Type: INDIA , Kerala, Idukki district, Ramakkalmedu 1500 m, 10.11.2002, C.N. Sunil 2267 (holo K; iso CAL!, CALI [ CALI112100 !], MH [ MH00003234 !]). FiGS. 17 , 18 & 22

Caespitose perennials. Culms up to 55 cm high, slender; nodes glabrous. Leaf sheaths 5–9 cm long, coriaceous, sparsely hispid; ligules with a tuft of hairs, hairs 1–2 mm long, basal leaf sheaths papery; leaf blades 20–62 × 0.2–0.3 cm, linear-lanceolate, flat or involute, glabrous or sparsely hairy on both surfaces, midrib inconspicuous, margins entire, acuminate. Racemes 15–45 cm long, 20–58 spikelets loosely or tightly arranged in rachis; rachis smooth, angular, glabrous. Spikelets 5–13 × 1.5– 2.5 mm, 6–14-flowered, secund, pale-green or yellow, distant, laterally compressed, florets loosely imbricate; callus bearded; rachilla usually not visible; lower glumes 2–3 × 1–1.5 mm, 1-veined, membranous, asymmetrical, and broadened on one-side below the middle, apex sub-acute, sometimes lobed; upper glumes 4–5 × 1–1.5 mm, lanceolate-oblong, 1-veined, membranous, apex acute, notched, mucronate, mucro 0.5 mm long, scabrous, the lateral lobes as long or shorter than the mucro; lemmas 3–3.5 × 2–2.5 mm, membranous, grey-green, 3-veined, 3-awned, median awn 2–2.5 mm long, straight, rigid, scabridulous, lateral awns up to 2 mm long, apex acute, 4-lobed, each lobe, 0.5–1 × 0.25 mm, ovate-lanceolate; paleas 2.5–3 × c. 1 mm, hyaline, obovate, apex obtuse or acute, bi-setaceous sub-apically, setae 0.25 mm long, curved, ciliolate; stamens 3, anthers 1–1.5 mm long; ovary c. 0.25 mm long, globose, styles 2, stigma 0.75 mm long, purplish, feathery. Caryopses 1.5–1.6 × 0.25–0.3 mm, oblong-lanceolate, cylindric, light brown.

Flowering & fruiting: Flowering and fruiting from October to late December.

Habitat: This species grows from 1000–1500 m elevations on seasonally wet rocky hillsides, in association with Apluda mutica L., Eragrostiella bifaria , Themeda tremula Hack. , Tripogon bromoides (all Poaceae ), Crotalaria beddomeana Thoth. & A.A.Ansari ( Fabaceae ), Henckelia incana ( Gesneriaceae ) and Leucas ciliata ( Lamiaceae ).

Distribution: Endemic to South India , hitherto known only from the type locality.

Specimens examined: INDIA , Kerala, Idukki district, Ramakkalmedu , 1500 m, 13.11.2014, K . Thoiba & A. K . Pradeep 137546; Ibid. , 16.12.2014, K . Thoiba & A. K . Pradeep 137584 ( CALI) .

Notes: Similar to Tripogon bromoides but can be identified by its sparsely hairy leaf blades, widely spread spikelets and paleas with an obtuse or acute apex with two sub-apical setae.

Figures

FiG. 17. Tripogon idukkianus Sunil & Pradeep in its natural habitat at Ramakkelmedu in Idukki distriCt (Photo by A.K. Pradeep).

FiG. 18. Tripogon idukkianus Sunil & Pradeep: a. Habit; b. Ligule; c. Spikelet; d. Lower glume; e. Upper glume; f. Floret; G. Lemma; h. Palea; i. LodiCule, stamen & pistil; j. Caryopsis.

FiG. 22. Distribution of Tripogon jaCQuemontii Stapf, T. idukkianus Sunil & Pradeep and T.karnatakensis Thoiba & Pradeep in India [drawn using ESRI (2011) ArCGIS Desktop: Release 10].