Urochloa trichopus (Hochst.) Stapf

Vorontsova, Maria S., 2022, Revision of some Malagasy forage grasses and their relatives within Brachiaria, Echinochloa, Moorochloa, and Urochloa, Candollea 77 (2), pp. 199-236 : 233-234

31. Urochloa trichopus (Hochst.) Stapf in Oliv., F l. Trop. Afr. 9: 589. 1920.

Panicum trichopus Hochst. in F lora 27: 254. 1844.

Holotypus: [ SUDAN]: cultivated in Cordofan , 1837, Kotschy 74 ( TUB ([ TUB006436 ] image!); iso-: BM ([ BM000923215 , BM000923216 ]!), G ([ G00022708 ] image!), K [ K000281979 , K000281980 ]!, MO [MO-1660898] image!, S [ S05-8793 ] image !, US [US-1125963]!, W [W0030715, W0030714, W18890243303, W19160023511 ] image !).

= Urochloa mosambicensis (Hack.) Dandy in J. Bot. 69: 54. 1931 . Panicum mosambicense Hack. in Bol. Soc. Brot. 6: 140. 1888. Holotypus: MOZAMBIQUE: continente fronteiro, 1884, de Carvalho 19 (W [ W19160023605 ] image!; iso-: COI, K [ K000281991 ]!).

Loosely tufted stoloniferous perennial, ascending to erect, to 0.2–1.5 m high, culms not branched, glabrous, nodes bearded, basal sheaths silky pubescent. Leaf sheath glabrous or sparsely pubescent towards apex, with ciliate margins. Ligule a line of hairs. Leaf blade broadly linear to narrow-lanceolate, chartaceous, 2– 30 × 0.3–2 cm, sparsely to densely pilose on both sides. Inflorescence racemose, thick, 7– 20 cm long. Racemes 3–15, 2–8 cm long, roughly even in length, on a common axis 3–12 cm long, with no secondary branching, rhachis narrowly winged, 0.8–1 mm wide, scaberulous to finely pilose, spikelets imbricate, single or paired, subsessile, subtended by a few long cilia. Spikelets ovate, plump, apically acuminate, 3–5 mm long, drying yellowish with silky-white hairs. Lower glume ⅔– ¾ as long as spikelet, membranous, obtuse, 3(– 5)-veined, side veins joining midvein near apex, often with a tuft of hairs from middle of back, turned away from rhachis. Upper glume as long as spikelet, membranous, long-acuminate, 7-veined, glabrous or pubescent. Lower floret male, palea as long as lemma, anthers 3, 1.5–2 mm long. Lower lemma membranous, long-acuminate with central nerve developing into a mucro, 5-veined, with cross veins towards apex, usually with a setose fringe. Upper lemma rounded, rugulose, with a mucro 0.5–1.2 mm long.

Distribution and ecology. – African species not present in the Mascarenes; only two localities are currently known from the western coast but it is likely the true distribution is more widespread. Not clear whether this species is native to Madagascar. Open secondary vegetation on sand, roadsides, at low elevations (F ig. 17).

Notes. – Distinctive by its odd obtuse lower glume with tuft of trichomes in the middle. Appears to be polyphyletic in HACKEL et al. (2018). The accession Vorontsova et al. 916 yielded three chloroplast regions which place it as sister to the African and Asian clade containing Urochloa reptans , U. glumaris , U. ramosa , U. praetervisa (Domin) Hughes, U. echinolaenoides Stapf , and U. setigera (Retz.) Stapf. Only one of these regions, ndhF, was available for the second accession from Kruger National Park, South Africa (YBK350 from BOUCHENAK‐KHELLADI et al., 2014) and the species was recovered as part of an African clade with U. rudis Stapf and U. panicoides . Good forage (BOSSER, 1969).

Additional specimens examined. – MADAGASCAR. Reg. Boeny [Prov. Mahajanga]: La Corniche, Kanto Hotel grounds, 14.II.2013, Vorontsova et al. 916 ( K, TAN) . Reg. Melaky [Prov. Mahajanga]: env. de Maintirano, II.1957, Service Veterinaire s.n. ( P) ; ibid. loco, X.1964, Morat 732 ( P, TAN) .