GrassBase - The Online World Grass Flora

Descriptions

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

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

Monocymbium lanceolatum

HABIT Perennial. Culms decumbent, or prostrate; 100–120 cm long; 2.5–3 mm diam.; rooting from lower nodes. Leaf-sheaths glabrous on surface, or pilose. Ligule an eciliate membrane; 1 mm long. Leaf-blade base amplexicaul. Leaf-blades lanceolate; 4.5–9 cm long; 10–20 mm wide. Leaf-blade margins scabrous; glabrous, or ciliate; hairy at base. Leaf-blade apex acute.

INFLORESCENCE Synflorescence compound; scanty; 20–45 cm long. Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; enclosed. Spatheole lanceolate; 2–3 cm long; membranous; brown, or red; glabrous. Peduncle 0.4–1.8 cm long; pubescent above.

Racemes 1; single; unilateral; 1.2–2.2 cm long; bearing few fertile spikelets; bearing 5–10 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Spikelet packing crowded. Rhachis internodes filiform; 1.5 mm long. Rhachis internode tip oblique.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; 2 mm long; ciliate.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; lanceolate, or oblong; dorsally compressed; 3–4.5 mm long; as long as fertile; separately deciduous. Companion sterile spikelet callus cuneate; 0.3 mm long; obtuse. Companion sterile spikelet glumes coriaceous; 9–15 -veined; glabrous, or villous; muticous. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 3.5–4 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus square; pilose; hairy on the sides; base obtuse; attached obliquely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume elliptic; 1 length of spikelet; coriaceous; without keels; keel-less except near apex; 9–15 -veined. Lower glume surface scabrous; rough at apex; villous. Lower glume apex entire. Upper glume lanceolate; chartaceous; without keels; keel-less except near apex; 3 -veined. Upper glume surface scabrous; rough at apex. Upper glume margins ciliolate. Upper glume apex dentate; 2 -fid; awned; 1 -awned. Upper glume awn 1–3 mm long.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 3–3.5 mm long; hyaline; 0 -veined; without midvein; without lateral veins; ciliolate on margins; emarginate, or truncate. Fertile lemma linear; 2.5–3 mm long; hyaline; without keel. Lemma apex lobed; 2 -fid; incised 0.4–0.6 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 12–16 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3; 2 mm long.

DISTRIBUTION Africa: west tropical.

NOTES Andropogoneae. FWTA.

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