Tripogon nallamalayanus Rasingam & J. Swamy, 2018

Rasingam, Ladan & Swamy, Jetti, 2018, A new species of Tripogon (Poaceae: Chloridoideae: Tripogoninae) from Nallamala forests, Telangana, India, Phytotaxa 351 (4), pp. 296-300 : 296-299

Tripogon nallamalayanus Rasingam & J. Swamy , spec. nov. ( Fig. 1 & 2 )

Diagnosis:— Tripogon nallamalayanus is closely allied to Tripogon trifidus , but differs in having glabrous leaf sheaths, longer spikelets and geniculate awn on lemma, 11–16 florets and obovate-oblanceolate palea.

Type: — INDIA, Telangana, Mahbubnagar district, Umamaheshwaram, 16.36989 N / 78.73168 E, 700 m, 22 October 2016, L. Rasingam & J. Swamy 7396 (holotype CAL!, isotypes BSID!).

Tufted perennials. Culms 20–30 cm high, erect; nodes ca. 1 mm long, glabrous. Leaf sheath terete, 6–11.5 × 0.12– 0.17 cm, glabrous; ligule 0.3–0.4 mm long, ca. 1.3 mm wide, membranous, truncate, ciliate at apex; leaf blades 17–37 × 0.04–0.12 cm, linear, filiform, convolute, scabrid along margins, acuminate at apex, 5–8-veined, scabrid on lower surface, especially on veins beneath, glabrous on upper surface. Inflorescences 17–24 cm long, 0.4–0.8 mm wide, spiciform; rachis flat, glabrous. Spikelets 11–16.2 × 1.42–72 mm (excluding awns), narrowly elliptic, laterally compressed, 11 − 16-flowered. Lower glumes 3.11–3.65 × ca. 0.65 mm, lanceolate, membranous, entire, acuminate at apex, glabrous, 1–veined, shallowly lobed on one side below the middle; upper glumes 4.38–4.88 × 0.58–0.69 mm, narrowly lanceolate, membranous, entire, acuminate at apex, 1–veined, glabrous. Lemmas 3.36–3.54 × 1.23–1.65 mm (excluding awn), membranous, ovate, glabrous at base, scabrid towards apex, 3–nerved, 1–keeled, 2–lobed, 1–awned, the awn 3.12–4.08 mm long, geniculate, arising from sinus, scabrid. Palea 2.44–2.48 × 0.83–0.93 mm, shorter than the lemma, obovate-oblanceolate, 2–keeled, the keels ciliate, hyaline, shortly bifid at apex. Lodicules 2, ca. 0.31 × 0.12 mm, wedge shaped, glabrous. Stamens 3, ca. 1.10 mm long; filaments ca. 0.22 mm long; anthers ca. 0.94 × 0.20 mm. Pistil ca. 1.48 mm long; ovary ca. 0.34 × 0.12 mm, glabrous; style 0.24–0.41 mm long; stigma feathery, 0.73–0.90 mm long; caryopsis not seen.

Etymology: —The new species is named after the type locality, Nallamala forests, a portion of the Eastern Ghats in Telangana state, southern India.

Phenology: —Flowering and fruiting in August to November.

Distribution and Ecology: — Tripogon nallamalayanus is currently known from Umamaheshwaram,Mahbubnagar district, Telangana. It grows on rocky cliffs and grassy slopes at an elevation of 700 m, in association with Tripogon bromoides Roth (1817: 600) , Eragrostiella bifaria (Vahl 1791: 19) Bor (1940: 270) , Heteropogon contortus ( Linnaeus 1753: 1045) Roemer & Schultes (1871: 836) , Lophopogon tridentatus Hackel (1889: 254) , Chamaecrista mimosoides ( Linnaeus (1753: 379)) Greene (1899: 27) and Sopubia delphinifolia G. Don (1837: 560) .

Note:— Tripogon tirumalae Chorghe et al. (2013) was described from Seshachalam Biosphere Reserve of Andhra Pradesh, which is related to T. trifidus and T. nallamalayanus to certain extent but differs from the latter by its culms and spikelets length (7–7.5 vs 11–16.2), number of florets (9–10 vs 11–16) and awn characters (not geniculate vs geniculate).

Figures

FIGURE 1. Tripogon nallamalayanus spec. nov. A. Habitat; B. Habit; C. Part of inflorescence.

FIGURE 2. Tripogon nallamalayanus spec. nov.A. Habit; B. Spikelet; C & D.Abaxial and adaxial surface of lower glume; E & F.Abaxial and adaxial surface of upper glume; G. Lemma; H. Palea; I. Stamens and pistil [from L. Rasingam & J. Swamy 7396 (BSID)].