Urochloa deflexa (Schumach.) H. Scholz

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 : 224

18. Urochloa deflexa (Schumach.) H. Scholz in Bull. Mus. Natl. Hist. Nat., B, Adansonia 11: 443. 1989 (F ig. 14A, B).

Panicum deflexum Schumach., Beskr. Guin. Pl. : 63. 1827. Panicum ramosum var. deflexum (Schumach.) Peter in Repert. Spec. Nov. Regni Veg. Beih. 40: 177. 1930. Brachiaria deflexa (Schumach.) C.E. Hubb. ex Robyns in Bull. Jard. Bot. État Bruxelles 9: 181. 1932.

Holotypus: GHANA: southern part of the country, s.d., Thonning 390 ( C [ C10004257 ] image!; iso-: C [ C10004258 , C10004259 ] image!, K [ K000282165 ]!) .

Loosely tufted annual, largely erect, to 0.7 m high, culms weakly branched, glabrous. Leaf sheath glabrous to sparsely pubescent towards top. Ligule a line of hairs. Leaf blade lanceolate, chartaceous, 8–17 × 0.4–1.2 cm, glabrous to sparsely pubescent on both sides. Inflorescence racemose, effuse, open, 5–15 cm long. Racemes 6–15, 2–8 cm long, flexuous, decreasing in length upwards, on a common axis 3–12 cm long, sometimes with small secondary branches, rhachis triquetrous, ciliate, spikelets not overlapping with adjacent spikelets, paired, sessile and shortly pedicelled in each pair, at least some pedicels longer than spikelets. Spikelets broadly elliptic, plump, apically apiculate, 3–3.3 mm long, whiteish. Lower glume c. ½ as long as spikelet, membranous, clasping, acute, 3–5-veined, glabrous to hirsute, separated from rest of spikelet by an internode c. 0.5 mm long, orientation relative to rhachis variable. Upper glume as long as spikelet, herbaceous, apiculate, 7-veined, veins pronounced, hirsute. Lower floret infertile, palea ⅔–¾ as long as lemma. Lower lemma herbaceous, 5-veined, cross veins sometimes visible, hirsute. Upper lemma acute, rugose.

Distribution and ecology. – Likely native, adventitious African and south Asian grass common in drier western and especially southern parts of Madagascar. Roadsides, dry forest and spiny forest understory, savanna, cultivation, on sand, laterite, and a variety of substrates, at elevations of 0–1300m (F ig. 13).

Notes. – A key character for Urochloa deflexa (Schumach.) H. Scholz is the presence of at least some pedicels which are longer than the spikelet (F ig. 14A, B). On smaller individuals the inflorescence is often larger than the rest of the plant. CLAYTON & RENVOIZE (1982) noted continuous variation between U. deflexa and U. ramosa (L.) T.Q. Nguyen but these seem to be distinct in Madagascar. The inflorescences of U. deflexa can appear to be paniculate rather than racemose, and it is therefore regularly mistaken for Panicum .

Urochloa deflexa is a weed of a broad range of arid lower elevation localities. It forms the ground cover in many disturbed areas, such as the Ankarafantsika National Park visitor centre. Unlike other parts of Africa, there is no evidence of the grain being eaten by people in Madagascar.

Selected specimens examined. – MADAGASCAR. Reg. Anosy [ Prov. Toliara]: 23–28 km W of Manambaro, 21.II.1975, Croat 31978 ( K, MO, TAN) ; Tolagnaro , Amboasary-Sud , Somangy , 8 km from Amboasary to Berenty, 15.III.2019, Rakotomalala et al. 274 ( K, TAN) . Reg. Boeny [ Prov. Mahajanga]: Ambondromamy, 13.II.2013, Vorontsova et al. 914 ( K, TAN) . Reg. AIANA [ Prov. Antsiranana]: Mailaka, II.1892, Douillot s.n. ( P) ; forêt d’Analamahitso au Sud d’Anivorano-Nord , XII.1937, Humbert 19069 ( P) ; Ambilobe , falaise de l’Ankarana, I.1969, Morat 3087 ( P) . Reg. Ihorombe [ Prov. Fianarantsoa]: bassin de la Malio, près d’Ambalabe, 23.XI.1946, Humbert 19468 ( P) ; près d’Ambalabe , 23.XI.1946, Humbert 20060[b] ( K, P, TAN) ; Ivohibe , haute vallée de la Menarahaka a l’E d’Ihosy, 28.I.1955, Humbert 28615 ( P) ; plateaux et vallées de l’Isalo à l’W de Ranohira, 29.I.1955, Humbert 29845 ( P) . Reg. Melaky [Prov. Mahajanga]: Mt Bevendro , Tsingy du Bemaraha, 25.XI.1932, Leandri 636 ( P) ; près d’Ambodiriana , entre Antsalova et Tsiandro, Ouest Antsingy forêt, 21.I.1960, Leandri 2672 ( P) .