Cenchrus orientalis (Rich.) Morrone

Veldkamp, J. F., 2014, A revision of Cenchrus incl. Pennisetum (Gramineae) in Malesia with some general nomenclatural notes, Blumea 59 (1), pp. 59-75 : 68-69

10. Cenchrus orientalis (Rich.) Morrone

Cenchrus orientalis (Rich.) Morrone in Chemisquy et al. (2010) 128. — Pennisetum orientale Rich. (1805) 72. — Panicum orientale Willd. (1809) 1031. — Pennisetum setaceum (Forssk.) Chiov. subsp. & var. orientale Maire (1940) 45. — Lectotype: Herb. Willdenow 1477­01 (holo B, IDC microfiche 7440), designated here.

Pennisetum triflorum Nees ex Steud. (1854) 107. — Pennisetum orientale Rich. var. triflorum Stapf (1896) 86. — Type: Royle 59 (holo P; B (extant?), K, LIV, K neg. 18368).

Perennials. Culms erect to geniculate at base, not rooting in the decumbent nodes, not stoloniferous, rhizomatous, 0.5–1 m long, nodes glabrous to pilose. Ligule a ciliolate rim, c. 0.15 mm long, setae c. 0.6 mm long. Blades flat, 10–50 cm by 3–12 mm, margins scaberulous. Peduncle glabrous to pilose below the panicle. Panicle exserted, many-spikeled, 18–25 cm long, common axis puberulous to pubescent. Involucre stipitate, disarticulating at base. Bristles many, rather stiff, pilose (some outer ones excepted), 8–15 mm long, one distinctly longer than the others, longest bristle 16–25 mm long. Spikelets 1–4 within the involucre (the terminal one bisexual, the others male, rarely bisexual), pedicelled, the bisexual ones 5–7 mm long. Lower glume 1.5–2.5 mm long, 0.39–0.48 times as long as the upper glume; upper glume 3–5 mm long, 1–3-nerved. First lemma paleate, male, acuminate to aristate, membranous, 5-nerved, glabrous, nerves scaberulous; second lemma 4.8–6.4 mm long, aristate, membranous. Anthers 2.6–3.5 mm long, apex glabrous. 2n = 18, 36, 45?, 54.

Distribution — E Africa, cultivated elsewhere, e.g. Malesia: Java, Philippines (Luzon: Manila),? Papua New Guinea (Morobe, NGF 27826 (Streimann & Kairo), BO, fide Ms Sad- soeitoeboen, Manokwari, pers. comm.; the specimen in L is P. polystachion ).

Habitat — Up to 1000 m altitude.

Uses — As a fodder plant, soil binder, ornamental.

Notes — Monod de Froideville (1968: 575) has misapplied the name P. orientale to P. setaceum , and P. triflorum to P. orientale . In most accounts the latter two are kept distinct, but the differences given appear to be untenable.

A puzzling population was found in an abandoned field near Desa Tonasa near Malino, SW Celebes, Veldkamp 8917, 14 Aug. 2008 (L), that keys out to P. orientale , but is not it. Superficially, it also resembles P. pedicellatum , but is not that, either.

Description

Plants perennial. Culms geniculate at base, not rooting in the decumbent nodes, not stoloniferous, rhizomatous, c. 1.5 m long, nodes pilose, but soon glabrous. Ligule a setose collar, c. 0.15 mm long, setae 1.8 mm long. Blades flat, 30 cm long, 4 mm wide, margins scaberulous. Panicle exserted, many-spikeled, 9 cm long, common axis pubescent. Involucre not stipitate, disarticulating at base. Bristles many, rather stiff, the inner ones pilose (some outer ones excepted), one distinctly longer than the others, 9–10 mm long, longest bristle 13–17 mm long. Spikelets 1 within the involucre, pedicelled, 5.2 mm long. Lower glume well-developed, 1.3 mm long, 0.28 times as long as the upper glume. Upper glume 4.6 mm long, 3-nerved. First lemma acuminate, membranous, 5-nerved, glabrous, nerves smooth. Second lemma not indurated, c. 4 mm long, obtuse. Anthers apex glabrous, apiculate.

–. Culms 0.5–1 m long. Ligule setae c. 0.6 mm long. Panicle 18–25 cm long. Involucre stipitate. Lower glume 1.5–2.5 mm long, 0.39–0.48 times as long as the upper glume. First lemma nerves scaberulous. Second lemma 4.8–6.4 mm long................................. C. orientalis

–. Culms 1.5 m long. Ligule setae c. 1.8 mm long. Panicle c. 9 cm long. Involucre not stipitate. Lower glume c. 1.3 mm long, c. 0.28 times as long as the upper glume. First lemma nerves smooth. Second lemma c. 4 mm long................................... Cenchrus Veldkamp 8917

–. Plants annual, not rhizomatous. Culms erect. Ligule a ciliolate rim, 0.4–1.3 mm long. Involucral bristles a few distinctly longer than the others, densely crinkly pilose around the spikelet (some outer ones excepted). Upper glume 5-nerved. First lemma erosely truncate. Second lemma 2.1–3.2 mm long.............................. C. pedicellatu s

–. Plants perennial, rhizomatous. Culms geniculate at base. Ligule a setose collar, 0.15 mm long, setae c. 1.8 mm long. Involucral bristles one only distinctly longer than the others, the inner ones pilose. Upper glume 3-nerved. First lemma acuminate. Second lemma c. 4 mm long........................................ Cenchrus Veldkamp 8917