Cenchrus ciliaris L., Mant. Pl. Altera 2: 302. 1771.

Wessapak, Paweena, Ngernsaengsaruay, Chatchai & Duangjai, Suthee, 2023, A taxonomic revision of Cenchrus L. (Poaceae) in Thailand, with lectotypification of Pennisetum macrostachyum Benth., PhytoKeys 234, pp. 1-33 : 1

2. Cenchrus ciliaris L., Mant. Pl. Altera 2: 302. 1771.

Figs 3 , 4

≡ Pennisetum ciliare (L.) Link, Hort. Berol. 1: 213. 1827.

= Pennisetum petraeum Steud., Syn. Pl. Glumac. 1: 106. 1854. Type: Iran, Mar 1842, C. G. T. Kotschy 170 (lectotype, designated by Gutiérrez and Morrone 2012, pg. 264: P [P00642074] seen on digital image; isolectotypes: K [K000244671!], P [P00642073] seen on digital image).

= Cenchrus longifolius Hochst. ex Steud., Syn. Pl. Glumac. 1: 109. 1854. Type: Sudan, Arasch-Cool, 16 Oct 1839, C. G. T. Kotschy 190 (holotype: P [P00442947!]; isotypes: BM [BM000923378!], E [E00200302] seen on digital image, G n.v., K [K000281252!], P [P00442951!, P00442948!]).

Type.

South Africa, Cape, Koenig s.n. (lectotype, designated by Clayton & Renvoize in Polhill (ed.) (1982, pg. 691): LINN [LINN-1217.9] seen on digital image) .

Description.

Perennial, tufted, Culms geniculate ascending, 45-75 cm high; nodes glabrous; internode subterete, 4-13 mm long, 1-2 mm in diam., glabrous. Leaf sheaths keeled conspicuous, 4-8 cm long, margins hairy, glabrous or hairy. Ligules a fringe of hairs, 1-1.5 mm long. Collar glabrous. Leaf blades linear, 16-32 cm × 2-7 mm, apex acute, base rounded, margins scabrous, chartaceous, both surfaces hairy or lower surface glabrous and upper surface pilose. Inflorescence spiciform panicle, 17-33 × 1.5-2.2 cm (including bristles); central axis angular, 6-11 cm long, axis internode 0.5-1.5 mm long, scabrous and puberulose; peduncle terete, 8-25 cm long, scabrous; short raceme along central axis; raceme with (1-)2-3(-4) spikelets in cluster, all sessile, subtended by an involucre of bristles. Involucre composed of outer and inner circles; outer circle usually shorter than inner circle; outer involucre of bristles, numerous and filamentous, free, 1-7 mm long, antrorsely scabrous; inner involucre of 8-13 slightly flattened bristles with 6-11 mm long, connate only at the base less than 1 mm long, one conspicuous longest bristle 0.9-1.4 cm long, hairy and antrorsely scabrous; involucre falling with spikelets; stipe (raceme-based) ca. 0.5 mm long, hairy. Spikelets dorsally compressed, lanceolate, 3-4.4 × 1-1.1 mm. Lower glume ovate, 1.7-2.4 × 0.8-1.2 mm, apex acute, membranous, glabrous, 1-nerved. Upper glume ovate, 2-3 × 1-1.3 mm, apex acute, membranous, glabrous, 1-nerved. Florets 2. Lower floret sterile, rarely male. Lower lemma lanceolate or ovate-lanceolate, 3-4 × 1-1.5 mm, apex acute or mucronate, membranous, glabrous, 5 or 7-nerved. Lower palea elliptic or oblong, 2-3 × ca. 0.6 mm, apex obtuse or acute, margins folded with antrorsely scabrous, membranous, glabrous, 2-nerved or palea absent. Upper floret bisexual. Upper lemma lanceolate, 3.2-4.3 × 1-1.2 mm, apex acute or acuminate, margins hyaline, chartaceous or coriaceous, glabrous, 5-nerved. Upper palea lanceolate, 3-4 × 0.7-1.2 mm, apex acuminate, margins hyaline, chartaceous or coriaceous, glabrous 2-keeled, 2-nerved. Lodicules absent. Stamens 3; filament ca. 3 mm long; anther yellow 1.5-2.5 mm long. Pistil ovary elliptic, 0.4-0.8 × 0.2-0.5 mm; style 2; stigma plumose. Caryopsis ellipsoid, 1.4-1.8 × ca. 1 mm.

Distribution.

Native to Africa, Greece, Sicilia, Middle East, Afghanistan, Pakistan, India and Bangladesh. Introduced to America, Australia and Southeast Asia.

Distribution in Thailand.

South-Western: Kanchanaburi (Sai Yok); CENTRAL: Nakhon Pathom (Kamphaengsaen, Mueang Nakhon Pathom).

Habitat and ecology.

In open areas by the roadside and the edge of rice fields. This species is cultivated for forage at elevations between 0 and 250 m a.m.s.l. Flowering and fruiting from May to September.

Vernacular name.

Ya khi khrok rayang phu (หญ้าขี้ครอกรยางค์พู่); African foxtail grass, Buffel grass (English).

Specimens examined.

Thailand. Kanchanaburi: Sai Yok , 17 May 2005, P. Porkar 17 (BKF, CMUB) ; Nakhon Pathom: Kamphaengsaen , 22 Jul 2017, P. Wessapak 373, 374 (BK); Mueang Nakhon Pathom, Thap Luang, 22 Jul 2017, P. Wessapak 376 (BK) .

Notes.

This species has been planted as fodder and to prevent soil erosion. It is considered as invasive in some countries. In Thailand, this species commonly escapes planting, but is not widely naturalised like the other species of the Cenchrus .

Figures

Figure 3. Cenchrus ciliaris L. A habit B ligule C spikelets with involucre D lower glumes E upper glumes F lower lemmas G lower paleas H upper lemmas I upper paleas J caryopsis. Drawn from P. Wessapak 376 by Paweena Wessapak.

Figure 4. Cenchrus ciliaris L. A habitat B inflorescence C, D spikelets with involucre. (Photographs: Paweena Wessapak).