Cenchrus caliculatus

Detailed description

Robust, through somewhat lax, spreading, clump-forming grass arising from a stout, woody rhizome; culms trailing and rooting freely from lower nodes. Branching initially extravaginal becoming intravaginal. Leaf-sheath longer than internodes, firm papery, keeled, smooth, minutely scabrid on narrow membranous margin and on ribs below collar. Ligule 1.0–1.5 mm, truncate with a densely ciliate rim. Leaf-bade 70–200 × 4–9 mm, linear-lanceolate, rounded-truncate at base, flat, firm, undersides smooth, upper surface minutely scabrid on ribs; margins somewhat thickened, minutely scabrid, tapering to a long acuminate apex. Culm 700 × 2–2.5 mm diameter, terete, more or less angled, internodes minutely pubescent-scabrid on ridges below panicle. Panicle 100–250 × 15 mm, spicate; rachis triangular, slightly winged, densely minutely pubescent-scabrid, bearing ovoid clusters of 1–3 spikelets, hidden amongst bristles and densely, spirally arranged along rachis; clusters 7–10 × 4–7 mm, including involucre of stiff bristles, at first appressed, finally borne at right angles to rachis; bristles retrorsely barbed, very variable in length, 0.5–11.0 mm, outermost smaller, terete, inner more planoconvex with margins densely softly long-ciliate, one bristle in each cluster usually exceeding the others. Spikelets 5–6 mm, 2-flowered, < inner bristles, sessile, glabrous, light green to almost colourless. Glumes hyaline; lower 2–4.5 mm, 1-nerved, upper 4–5 mm, 5-nerved. Lower floret with lemma 4.8–6.0 mm, 5-nerved, scabrid; palea keels ciliate, interkeel minutely hairy, margins scabrid; anthers 1.5–2.0 mm, brown with thick orange-yellow filaments. Upper floret with lemma 5.0–5.5 mm, 5-nerved, finely scabrid-papillose; palea finely scabrid-papillose; anthers as in lower floret. Seed 2.2–2.7 mm, more or less ellipsoid.