GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Pogonatherum biaristatum

HABIT Perennial; mat forming. Culms erect, or geniculately ascending; 40–60 cm long; 1–2 mm diam.; wiry; 10–13 -noded. Culm-nodes bearded. Lateral branches ample. Leaf-sheaths mostly shorter than adjacent culm internode; glabrous on surface, or pilose. Ligule a ciliolate membrane; 0.3–0.7 mm long; pubescent on abaxial surface; truncate, or obtuse. Leaf-blades 2–4.5 cm long; 1–3 mm wide; stiff. Leaf-blade surface glabrous; hairless throughout, or except near base. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary. Axillary inflorescences present throughout the plant; similar to terminal. Peduncle flexuous.

Racemes 1; single; 2–3 cm long; 2 mm wide. Rhachis fragile at the nodes; subterete; villous on margins. Rhachis internodes linear.

Spikelets in pairs. Fertile spikelets sessile and pedicelled; 2 in the cluster; the upper smaller. Pedicels linear; villous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 2–3 mm long; falling entire; deciduous from the base and with accessory branch structures. Spikelet callus pilose, or bearded; base obtuse; attached transversely. Spikelet callus hairs white; 0.5–3 mm long; 0.2–1 length of spikelet.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume oblong; 2.5 mm long; 0.8 length of upper glume; 0.8 length of spikelet; cartilaginous; much thinner on margins; without keels; 5 -veined. Lower glume surface scabrous; glabrous to pubescent. Lower glume apex truncate, or obtuse; awned; 1 -awned. Lower glume awn 15 mm long. Upper glume elliptic; cartilaginous. Upper glume surface scabrous. Upper glume apex dentate; 2 -fid; awned; 1 -awned. Upper glume awn 16–17 mm long.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret linear, or lanceolate; hyaline; 0 -veined; without midvein; without lateral veins. Fertile lemma oblong; 1.5–2 mm long; hyaline; without keel; 1 -veined. Lemma margins ciliolate; hairy above. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 17.5 mm long overall; with twisted column. Palea lanceolate, or oblong; hyaline; without keels.

FLOWER Lodicules absent. Anthers 1, or 2.

FRUIT Caryopsis with adherent pericarp; fusiform, or oblong, or ovoid.

DISTRIBUTION Asia-temperate: China.

NOTES Andropogoneae. Chen & Sheng 1996.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.