Arundinella fuscata Nees ex Buse

Veldkamp, J. F., 2015, Arundinella (Gramineae) in Malesia with notes on other taxa and on aluminium accumulation, Blumea 59 (3), pp. 167-179 : 176

2. Arundinella fuscata Nees ex Buse

Arundinella fuscata Nees ex Buse in Miq.(Feb.1854) preprint:19;(Aug.1854) 359; Nees ex Steud. (1854a) 114, isonym. — ( Arundinella (Acratherum) fuscata Nees in Wight (1834) 97, nom. nud.). — ( Acratherum fuscatum Nees ex Steud. : B.D.Jacks. (1895) 32, nom. inval., in syn.). — Type: Wight Cat. 1667 ≡ Wight Herb. Propr. 183 (holo U (now L); K, LE (Herb. Trin. 405.1, IDC microfiche BT-16/1), P). Both not in B (Scholz, 16 July 2003, pers. comm.).

Arundinella purpurea Hochst. ex Steud. (1854a) 115. — Type: Hohenacker 928 (holo P; G, K, L, M, U (now L), US].

Arundinella purpurea Hochst ex Steud.var. laxa Bor (1955) 407. — Syntypes: Gamble 13365, 20617 (K), Madras, Nilgiri, Sispara.

Plants perennial. Culms tufted, erect to geniculate at base, 0.35–0.85 m long. Nodes glabrous, puberulous, or bearded. Sheaths puberulous to densely pilose with bb hairs, glabrescent. Throat hairy. Ligule 0.4–1 mm high, glabrous or ciliolate. Blades flaccid to rather stiff, flat or involute, linear, 4.5–30 cm by 3–15 mm wide, usually pilose on both sides, margins scaberulous. Peduncle pilose under the panicle. Panicle densely contracted, rarely fairly lax, not interrupted at base, 3–20 by 1.5–2.5 cm, lowermost branch solitary, 1–4 cm long, angular, scabrous to puberulous, not pilose. Pedicels scaberulous and puberulous. Spikelets 3–4.5(–5.5) mm long, purple suffused. Glumes glabrous; lower glume 2.2–4 mm long, 0.59–0.75 times as long as the spikelet, slightly shorter than the lower lemma, apex acute, 3-nerved; upper glume 5-nerved, apex long-acuminate. Lower lemma neuter or male, 2.6–4 mm long, 3- or 5-nerved, apex acute; upper lemma 1.5–2 mm long, castaneous in fruit, microscopically scaberulous (40 ×!), 0-nerved, callus glabrous or puberulous, hairs 0.3 mm long, callus hairs 0.15 times as long as the lemma, apex acute, without lateral setae, awned or muticous, awn distinctly exserted beyond the glumes, geniculate, 3–6 mm long when dry, column 1–2 mm long when dry. Anthers 3, 0.75–1.8 mm long.

Distribution — S India: Karnataka, Kerala, Tamil Nadu.

Habitat — Open pastures, road cuttings, marshes often with A. vaginata Bor and Eulalia phaeothrix (Hack.) Kuntze , river bed, 1040–2500 m altitude.

Notes — Here we have a problem that by lack of material I cannot solve and gladly delegate to Indian botanists.

Species have been distinguished by the presence of an awned upper lemma and hairs on the callus.

In the isotype of A. fuscata (U) there is an awn and the callus is puberulous. Using the keys of Bor (1955, 1960) and Sreekumar & Nair (1991) this would belong to what they call A. purpurea . Among the 5 isotypes of A. purpurea there were inflorescences with no or very few awned upper lemmas, and others with predominantly awned ones. It is not, as Steudel presumed, because the awns have fallen off. The only other collection available, Perrotet 1231 from the Nilgiris, was a similar mixture. In these collections the calli were glabrous.

I have assumed that all are conspecific.

Some spikelets of the var. laxa are proliferous. It is noted to grow together with the typical variety, so one wonders whether it should be distinguished, and a new combination is not proposed here.