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.

Microstegium clavigerum

HABIT Annual. Culms rambling; slender; 25–35 cm long; rooting from lower nodes. Culm-internodes terete; distally glabrous. Leaf-sheath oral hairs scanty. Ligule an eciliate membrane; 0.75 mm long. Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades lanceolate, or ovate; 1.5–3 cm long; 6–10 mm wide. Leaf-blade surface pilose; sparsely hairy; hairy on both sides. Leaf-blade margins smooth.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; straight, or arcuate; 3–7 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes pyriform; 3.5–4 mm long.

Spikelets in pairs. Fertile spikelets sessile and pedicelled; 2 in the cluster; the upper smaller. Pedicels clavate; 2–4 mm long; ciliate.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 5.5–7 mm long; falling entire; deciduous from the base and with accessory branch structures. Spikelet callus pilose; base obtuse; attached transversely. Spikelet callus hairs 1–3 mm long.

GLUMES Glumes dissimilar; firmer than fertile lemma. Lower glume elliptic; 1 length of spikelet; coriaceous; 2-keeled; keeled obtusely; winged on keel; winged narrowly; winged above; 6–8 -veined. Lower glume surface concave; scabrous. Lower glume margins ciliate. Lower glume apex dentate; 2 -fid. Upper glume elliptic; 1-keeled. Upper glume primary vein ciliate. Upper glume margins ciliate. Upper glume apex acute; awned; 1 -awned. Upper glume awn 2–3 mm long.

FLORETS Basal sterile florets developed, or with vestigial lower floret; male; with palea. Lemma of lower sterile floret linear, or lanceolate; 4 mm long; hyaline; pilose; hairy at apex. Palea of lower sterile floret 4–5 mm long; pubescent; adorned on back. Fertile lemma lanceolate; 1.5–2.25 mm long; hyaline; without keel; 0 -veined. Lemma apex lobed; 2 -fid; incised 0.33 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 11–16 mm long overall; with twisted column. Palea oblong; 1.25–2 mm long; 0 -veined. Palea apex ciliate.

FLOWER Anthers 3; 2.5–3.5 mm long.

DISTRIBUTION Asia-tropical: Malesia.

NOTES Andropogoneae. Fl Java 1997.

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