Urochloa brizantha (Hochst. ex A. Rich.)

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 : 223

17. Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster, Austral. Paniceae ( Poaceae ) 233. 1987 (F ig. 11D–F).

Panicum brizanthum Hochst. ex A. Rich., Tent. F l. Abyss. 2: 363. 1850. Brachiaria brizantha (Hochst. ex A. Rich.) Stapf in Oliv., F l. Trop. Afr. 9: 531. 1919.

Lectotypus (designated by VELDKAMP, 1996: 417): ETHIOPIA. Tigray: Mt. Scholoda (Selleuda), X.1837, Schimper 89 ( P [ P00442084 ]!; isolecto-: BM [ BM 000923191 ]!, BR [ BR0000008645142 , BR0000008366955 ] images!, G [ G 00015881 , G00015882 , G 00015883 , G 00015884 ] images!, GOET [ GOET006080 ] image!, K [ K000282126 , K000282127 , K000282128 ]!, L [ L0043836 , L0043837 ] images!, LG [ LG0000090036057 , LG0000090036200 ] images!, M [ M0103976 , M0103977 ] images!, MO [MO-1742002] image!, MPU [ MPU024477 , MPU024478 ] images!, P [ P00442082 , P00442083 , P00731455 , P02284802 , P02284803 ]!, PRE [ PRE0664145 -0] image!) .

Tufted perennial, firmly rooted and almost woody near base of mature stand, ascending to erect, 0.3–2 m high, culms not branched, glabrous to sparsely hirsute. Leaf sheath glabrous to sparsely pilose. Ligule a ciliate membrane. Leaf blade broadly linear, chartaceous, 10–100 × 0.3–2 cm, glabrous to sparsely pilose on both sides. Inflorescence racemose, stout, erect, 5– 25 cm long. Racemes 2– 16, 4–20 cm long, usually gently curved, on a common axis 3– 20 cm long, with no secondary branching, rhachis herbaceous, curved, 1–1.5 mm wide, margin ciliate with trichomes 1.5 – 3 mm long, spikelets imbricate, single, subsessile, in a single row. Spikelets plump elliptic to obovate, apically subacute, 4–6 mm long, whiteyellowish, often with a purple tinge. Lower glume c. ⅓ as long as spikelet, membranous, clasping, acute or obtuse, 5-veined, glabrous, separated from rest of spikelet by a short internode, turned towards rhachis. Upper glume almost as long as spikelet, cartilaginous, dully shining, 5–7-veined, glabrous or pubescent. Lower floret male, palea as long as lemma. Lower lemma somewhat concave, cartilaginous, dully shining, 5–7-veined, glabrous or pubescent. Upper lemma acute, smooth to rugulose.

Distribution and ecology. – Recorded occurrences appear to reflect past forage plantings along roadsides, as well as agricultural stations. Open roadside grazing lawns, at elevations of 800–1600 m (F ig. 13).

Notes. – African forage species bred as a forage crop, introduced to Madagascar in the twentieth century, and now grown as a successful forage crop in the highlands (BOSSER, 1969). Agricultural literature in Madagascar frequently refers to “brachiaria”, which appears to indicate this species rather than any of the others.

In spite of the comparatively low number of herbarium records, Urochloa brizantha is commonly seen naturalised on the roadsides, for example in Ankafobe and near Moramanga. Usually seen forming a dense monotypic sward of firmlyrooted erect plants with woody culm bases (F ig. 11D – F). Diagnostic characters of U. brizantha include shiny cartilaginous upper glume and lower lemma (herbaceous in U. eminii , including the previously distinct species Brachiaria ruziziensis R. Germ. & C.M. Evrard ), narrow rhachis (wide in U. eminii ), and tufted habit (stoloniferous in U. eminii ), although all of these intergrade into U. eminii .

Additional specimens examined. – MADAGASCAR. Reg. Alaotra-Mangoro [Prov. Toamasina]: Alaotra Agricultural Station, IX.1953, Bosser 7103 ( TAN); Alaotra , XII.1963, Morat 251 ( TAN); Moramanga , road from Andasibe to Vakona, turnoff towards Ambatovy mine , 22.II.2019, Vorontsova et al. 2396 ( K, TAN). Reg. Analamanga [Prov. Antananarivo]: Manjakandriana , Sohisika Association office at entrance to Ankafobe PA, 1.III.2019, Vorontsova et al. 2398 ( K, TAN). Reg. Bongolava [Prov. Antananarivo]: Kianjasoa, 15.IV.1962, Boudet 1157 ( P [ P02520029 ]) .