帝汶鸭嘴草 di wen ya zui cao

Andropogon timorensis (Kunth) Steudel.

Annual or short-lived perennial. Culms slender, loosely tufted or stoloniferous, rooting at lower nodes, branching, flowering shoots 15–50 cm tall, nodes bearded. Leaf sheaths glabrous except toward throat, sometimes margins ciliate; leaf blades linear-lanceolate, 2–8 × 0.2–1 cm, glabrous or pilose with tubercle-based hairs, margins scabrid, base attenuate, apex acuminate; ligule 1–2 mm. Racemes terminal and axillary, paired (rarely 3), loosely arranged, 2–10 cm; rachis internodes and pedicels columnar, triquetrous, ciliate along angles. Sessile spikelet broadly elliptic, 3.5–6 × 1.2–1.5 mm; callus hairs 0.5–1 mm, white; lower glume smooth, glossy, leathery with rounded flanks in lower half, upper half papyraceous, prominently many-veined, asperulous, flanks keeled, keels scabrid, wingless, abruptly narrowed to bicuspidate apex; upper glume keeled above middle, keel wingless, apex narrowed into 2–4 mm awnlet; awn of upper lemma 1–1.6 cm. Pedicelled spikelet laterally compressed, resembling sessile, upper lemma awned.

Fields, damp wayside places; below 100 m. Guangdong, Taiwan [India, Indonesia, Malaysia, Myanmar, Sri Lanka, Thailand; introduced in Africa and America].

The lower glume of the sessile spikelet occasionally has very narrowly winged keels, but the narrowed, sharply bicuspidate apex is characteristic, differing from the more rounded lower glume apex of Ischae-mum ciliare. Axillary inflorescences are also uncommon in I. ciliare.