Arundinella pumila (Hochst. ex A.Rich.) Steud.

Veldkamp, J. F., 2015, Arundinella (Gramineae) in Malesia with notes on other taxa and on aluminium accumulation, Blumea 59 (3), pp. 167-179 : 174

6. Arundinella pumila (Hochst. ex A.Rich.) Steud.

Arundinella pumila (Hochst. ex A.Rich.) Steud. (1854a) 114. — Acratherum pumilum Hochst. ex A.Rich.(1851) 414. — Lectotype: Schimper 642 (holo B; K, P), designated by Van der Zon (1992:361). Phillips (1995: 285) stated that the holotype is in P, which is more logical as that is where Richard’s main herbarium is.

Arundinella effusa C.E.Hubb.(1957) 63 ( Clayton 1972:414, in syn.). — Type: FHI 28524 (Keay & Russell) (holo K).

Arundinella tenella Nees (& Wight ex Steud. (1840) 143, nom. nud.) ex Steud. (1854a) 115. — ( Anemagrostis tenella Wight ex Steud. (1854a) 115, in syn.). — Lectotype: Wight Herb. Propr. 76 =? Cat. 1668 (holo P; K, LE (Herb. Trin. 405.5, IDC microfiche BT-16/1)); ‘Herb. Wight’, partly designated by Bor (1955: 403), designated here.

Plants annual. Culms more or less solitary, erect, geniculate bat base, 0.04–0.45 m long. Nodes puberulous. Sheaths glabrous to margins hairy to pilose with bb hairs. Throat glabrous. Ligule 0.8–1 mm high. Blades flaccid, flat, oblong to linear, 1.7–20 cm by 2– 20 mm, glabrous to sparsely pilose on both sides, margins smooth to scaberulous. Peduncle glabrous under the panicle, rarely with a few hairs under the panicle. Panicle effuse, not interrupted at base, 2–33 by 1–22 cm, lowermost branches 1–6 together, longest one 3–20 cm long, terete (filiform), smooth, not pilose, rarely or sparsely pilose. Pedicels smooth. Spikelets 1.5–2.2 mm long, whitish with green nerves. Glumes glabrous, or the upper one with a few hairs; lower glume 1–1.6 mm long, 0.55–0.76 times as long as the spikelet, slightly shorter than to about as long as the lower lemma, 1- or 3-nerved apex acuminate or mucronate; upper glume 1–5-nerved, apex acuminate to long-acuminate. Lower lemma neuter, male, or bisexual, 1.3–1.4 mm long, 1–5-nerved, apex acute; upper lemma 0.8–1 mm long, castaneous in fruit, minutely scaberulous (40 ×!), 0-nerved, callus hairs 0.1–0.2 mm long, 0.13–0.28 times as long as the lemma, apex acute, without lateral setae, awn distinctly exserted beyond the glumes, geniculate, 2–3.4 mm long when dry, column 0.7–1.4 mm long when dry. Anthers 3, 0.3–0.5 mm long. 2n = 24.

Distribution — W to E Africa, Oman, India to Malesia: Java (very rare in Pasuruan, once in W Java, Pryer A˚ 1900, B, L), SW Celebes, Lesser Sunda Isl. ( Flores, Lombok, Sumbawa).

Habitat — Shady, humid places, steep roadsides, moist stones, base of waterfall, locally common, 700–1350 m altitude.

Note — Distribution disjunct. Technically very close to A. holcoides , but usually easily recognised by the effuse panicle that has the base still inside the sheath of the flag leaf.