Brachiaria perrieri A. Camus

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 : 212-213

8. Brachiaria perrieri A. Camus in Bull. Soc. Bot. F rance 77: 639. 1931.

Holotypus: MADAGASCAR. Reg. Haute Matsiatra [Prov. Fianarantsoa]: près d’Ambalavao , 800 m, VIII.1923, Perrier de la Bâthie 14438 ( P [ P00450187 ]!; iso-: P [ P00450188 ]!) .

Loosely tufted annual, erect, 10 – 45 cm high, culms not branched, sometimes rooting at lower nodes, pubescent, nodes bearded. Leaf sheath pubescent. Ligule a line of hairs. Leaf blade ovate, chartaceous, 1–4 × 0.3–1.3 cm, densely pilose on both sides. Inflorescence racemose, slender, contracted, 3–6 cm long. Racemes 5– 12, 1– 1.8 cm long, roughly even in length, appressed, on a common axis 1.5–5 cm long, with no secondary branching, rhachis narrow, ciliate, spikelets overlapping with adjacent spikelets, single, subsessile, in 2 rows. Spikelets ovate, apically acute, 2– 3 mm long, densely covered with white to pink trichomes. Lower glume c. ⅔ as long as spikelet, membranous, acute, 3-veined, densely pilose with white cilia, turned towards rhachis. Upper glume almost as long as spikelet, herbaceous, apiculate, 5-veined, veins poorly visible, with short white trichomes in lower part and dense white to pink trichomes c. 2 mm long in upper third. Lower floret male, palea as long as lemma. Lower lemma herbaceous, grooved, with a mucro c. 0.5 mm, 5-veined, veins poorly visible, pilose with sparse white trichomes in lower part and dense pink trichomes c. 2 mm long in upper part. Upper lemma apiculate, minutely striate.

Distribution and ecology. – Occurs across the central and southern part of the highlands, sometimes further south, on inselbergs and rocky slopes often associated with Styppeiochloa De Winter, commonly found on open wet rock after the rains, at elevations of 800–1500 m (F ig. 5).

Notes. – Attractive plant tinged with pink, and an easy to recognise endemic species. All collections have been made in the rainy period between January and March. Related to the endemic genus Yvesia A. Camus.

The sheet P00450187 is considered here as the holotype because it is labelled as “type” in Camus’ hand and there is no evidence that he used the duplicate for describing the new species.

Selected specimens examined. – MADAGASCAR. Reg. Androy [Prov. Toliara]: Ampandrandava entre Bekily et Tsivory , III.1943, Seyrig 565 ( P) . Reg. Haute Matsiatra [Prov. Fianarantsoa]: environs d’Ambalavao , II.1956, Bosser 8998 ( P) ; Isorana, II.1961, Bosser 15180 ( P) ; rte. Ambalavao-Ihosy PK 543, II.1963, Bosser 17875 ( P) ; Ambalavao , Iarintsena , Tananomby, 15.III.2010, Rakotoarivelo et al. 225 ( MO, P) . Reg. Ihorombe [Prov. Fianarantsoa]: entre Ambalavao et Ihosy PK 547, II.1962, Bosser 15630 ( P) ; S du radier d’Ampandrabe , Horombe, II.1965, Morat 2127 ( P) ; Horombe plateau, II.1967, Morat 2646 ( P) ; mont Belamboany , III.1912, Perrier de la Bâthie 11919 ( P) ; Bonnet du Pape , RN 7, 22.III.2010, Ramandimbisoa et al. 130 ( MO, P) . Reg. Itasy [Prov. Antananarivo]: PK 23 rte. de Arivonimamo, I.1957, Bosser 10665 ( P) ; Arivonimamo , Andranomena , 12.III.2011, Ramahefaharivelo 396 ( MO, P) .