Cenchrus brownii Roem. & Schult.

Veldkamp, J. F., 2014, A revision of Cenchrus incl. Pennisetum (Gramineae) in Malesia with some general nomenclatural notes, Blumea 59 (1), pp. 59-75 : 66

3. Cenchrus brownii Roem. & Schult.

Cenchrus brownii Roem. & Schult. (1817) 258. — Cenchrus inflexus R.Br. (1810) 195, non Poir. (1804). — Type: R. Brown 6140 (holo BM; E, K, P, US, fragm.).

Cenchrus viridis Spreng. (1824) 301. — Cenchrus echinatus L. var. viridis Spreng. ex Griseb. (1864) 556. — Type: Bertero s.n. (holo B; US, fragm.).

Cenchrus hexaflorus Blanco (1837) 36. — Type: not extant. — Neotype: Merrill Sp. Blancoan. 811 (holo US; BO, K, L, MO, NSW, P; expected in A, B, BM, CAL, F, GH, NY, U, UC, W), here designated.

Cenchrus echinatus auct. non L.

Cenchrus echinatus L. var. glabratus auct. non F.Br.: F.Br. (1931) 66, quoad BS 5995 (Ramos) (BISH).

Pennisetum macrostachys auct. non Trin. ( ‘ macrostachyum ’).

Pennisetum nigricans auct. non Miq.

Annuals. Culms 0.25–1 m long, erect to geniculate at base, rooting in the decumbent nodes. Ligule 0.75–1.7 mm long. Leaf blades 8–38 cm by 4–15 mm. Inflorescence 3–8(–12) cm long. Common axis scaberulous, internodes 0.8–2.25 mm long. Stipe 1–1.5 by 0.45–1.5 mm, base obconical, pubescent. Burs crowded, 4.7–7 by 2.4–4.9 mm, tawny and becoming purple. Outer main bristles subequal to longer than the inner spines, retrorsely barbed. Inner spines 6–10, connate for more than halfway above the base, forming a closed bur, erect to interlocking, subequal, puberulous to margins pilose. Spikelets 2–4 per bur, 4.3–6.45 mm long. Lower glume absent to 2.5 mm long, 1-nerved; upper glume 3.15–5.25 mm long, 3–5-nerved. First lemma epaleate to paleate, sterile to male, 4–6 mm long, 3–5-nerved; second lemma 4.3–6.45 mm long. Anthers 0.8–1.5 mm long. 2n = 34, 36.

Distribution — Originally from Central and South America, introduced elsewhere, e.g. Malesia: widespread, but local.

Habitat — Sandy beaches, waste places, roadsides, rail- roads, rice fields, 0–600(–1800) m altitude.

Uses — Highly palatable and nutritious when not in fruit, then an obnoxious weed, because of its clinging burs. Roots pound- ed and applied to wounds. Grains edible.

Vernacular names — Burr grass, Fine-bristle sandbur, Green sandbur, Slimbristle sandbur.

Note — Very similar to C. echinatus and often confused with it. It differs from that mainly by the more dense inflorescence and the longer outer main bristles, but some specimens remained difficult to place. Nearly all records for Malesia of C. echinatus belong to the present species.