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 petiolare

HABIT Perennial. Culms rambling, or scandent; 60–100(–400) cm long; rooting from lower nodes. Culm-nodes pubescent. Leaf-sheaths outer margin hairy. Ligule an eciliate membrane; 3–6 mm long. Leaf-blade base with a false petiole. Leaf-blades lanceolate, or elliptic; 5–30 cm long; 10–25 mm wide. Leaf-blade surface pilose; sparsely hairy; with tubercle-based hairs. Leaf-blade margins scabrous. Leaf-blade apex acuminate; filiform.

INFLORESCENCE Inflorescence composed of racemes. Peduncle glabrous, or pubescent above.

Racemes 8–20; digitate; 6–10 cm long. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes filiform; 3–4.5 mm long.

Spikelets in pairs. Fertile spikelets sessile and pedicelled; 2 in the cluster. Pedicels filiform; angular; ciliate.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 4.5–5 mm long; falling entire; deciduous from the base, or with accessory branch structures. Spikelet callus base obtuse; attached transversely.

GLUMES Glumes dissimilar; firmer than fertile lemma. Lower glume elliptic; 1 length of spikelet; coriaceous; 2-keeled; keeled obtusely; 6–8 -veined. Lower glume primary vein scabrous. Lower glume surface with a longitudinal median groove; scabrous. Lower glume apex acute. Upper glume oblong; membranous, or chartaceous; 1-keeled; 1–3 -veined. Upper glume primary vein scabrous. Upper glume apex acute; muticous.

FLORETS Basal sterile florets male, or barren; with palea. Lemma of lower sterile floret linear; 3–4 mm long; hyaline; ciliate on margins; obtuse. Palea of lower sterile floret 0.5–0.66 length of lemma. Fertile lemma oblong; 3 mm long; hyaline; without keel. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 4–6 mm long overall; with twisted column. Palea 1 length of lemma; hyaline. Palea surface pilose; hairy on flanks.

FLOWER Lodicules 2. Anthers 3; 2.5–3 mm long.

DISTRIBUTION Asia-temperate: China. Asia-tropical: India and Indo-China.

NOTES Andropogoneae. Bor.

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