亥氏草屬

Annuals; culms solid, glabrous or with sparse, long, sharp, tubercle-based hairs. Ligule short, ciliate; blades linear or linear-lanceolate, with long tubercle-based hairs beneath or on both sides; inflorescence a raceme. Spikelets small, in alternate pairs along rachis of small, spike-like, pedunculate racemes, subtended by a spathe-like leaf, pairs of spikelets dorsiventrally arranged, the uppermost joint of the raceme with 1 sessile and 2 pedicellate spikelets; pedicels totally fused with adjacent rachis-joint, together forming a cavity. Sessile spikelets globose or elliptic, with swollen, smooth or finely tuberculate, glabrous base, muticuous; lower glume abaxial, globose-convex, prominently tessellate-ribbed, finely tuberculate, hard, with margins pressed against rachis, blackish-brown at maturity, upper glume shorter and narrower, convex, sunk into a cavity of and partially fused with rachis , elliptic, rather hard, 1-nerved, with keel thickened at apex; lower lemma rather strongly convex, 3-nerved, marginal nerves easily separating from central part, glabrous; lower palea wanting; upper lemma and palea smaller, hyaline, oval, obtuse, nerveless; lodicules 2, cuneate; stamens 3, the anthers small, with 2-fid base and apex; styles 2, rather short, the stigmas short, apically exserted together with stamens. Caryopsis broadly elliptic. Pedicelled spikelets strikingly different from the sessile, ovate, flat or faintly convex, not blackish-brown at maturity, the higher ones often reduced; lower glume as long as spikelet, ovate, rather acute, with flat or faintly convex back, finely tuerculate, 4-6-nerves, the marginal nerves prominent; upper glume equally long, strongly obtuse, thin, glabrous, 2-nerved; upper lemma and palea ovate, acutish, nerveless. In all neuter spikelets the lemmas, the upper palea and stamens are all or partly abortive.

Only one or two speices in the tropical regions of the world; one species, H. granularis is found in Taiwan.

Lower Taxon

• Hackelochloa granularis (L.) Kuntze