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.

Cynosurus polybracteatus

HABIT Annual; culms solitary, or caespitose. Culms erect, or geniculately ascending; 10–80 cm long. Culm-internodes striate; smooth; distally glabrous. Culm-nodes brown. Leaf-sheaths without keel; striately veined; smooth; glabrous on surface. Ligule an eciliate membrane; 1.5 mm long; lacerate; truncate. Leaf-blades 7–15 cm long; 1–3.5 mm wide. Leaf-blade surface smooth, or scaberulous; rough abaxially; pubescent; hairy adaxially. Leaf-blade margins scabrous. Leaf-blade apex abruptly acute, or acute; callose.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear; secund; 1.5–9 cm long; 0.3–0.6 cm wide. Panicle axis angular; pubescent. Panicle branches scabrous.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets sessile; 1 in the cluster.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas; cuneate; laterally compressed; 4 mm long; as long as fertile; persistent. Companion sterile spikelet glumes herbaceous; 3.5–4 mm long; keeled; winged on keels; 1 -veined; scabrous (on keel); mucronate (mucro 0.2–0.5mm). Companion sterile spikelet lemmas 6–10; exserted from glumes; 3.5–4 mm long (linear); muticous (mucronate).

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 4 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes glabrous.

GLUMES Glumes persistent; similar; reaching apex of florets, or exceeding apex of florets. Lower glume lanceolate; 3.5 mm long; 1 length of upper glume; chartaceous; much thinner on margins; 1-keeled; 1 -veined. Lower glume primary vein smooth, or scaberulous. Lower glume lateral veins absent. Lower glume apex acuminate; mucronate. Upper glume lanceolate; 4 mm long; chartaceous; with hyaline margins; 1-keeled; 1 -veined. Upper glume primary vein smooth, or scaberulous. Upper glume lateral veins absent. Upper glume apex acuminate; mucronate.

FLORETS Fertile lemma oblong; 2.5–2.8 mm long; chartaceous; without keel; 5 -veined. Lemma surface scabrous. Lemma apex emarginate, or obtuse; muticous. Palea lanceolate; 1 length of lemma. Palea keels scabrous. Palea surface scaberulous. Palea apex obtuse.

FLOWER Lodicules 2; ovate; 0.5 mm long; membranous; acute. Anthers 3; 1.5 mm long.

FRUIT Caryopsis with adherent pericarp; oblong; dorsally compressed; 1.6–1.8 mm long; dark brown; glabrous. Embryo 0.25 length of caryopsis. Hilum elliptic; 0.2 length of caryopsis.

DISTRIBUTION Africa: north.

NOTES Poeae. Fl Afr Nord 1999.

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