Brachiaria epacridifolia (Stapf) 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 : 209-210

5. Brachiaria epacridifolia (Stapf) A. Camus in Bull. Mus. Natl. Hist. Nat., sér. 2, 22: 297. 1950.

Panicum epacridifolium Stapf in Bull. Misc. Inform. Kew 1919: 266. 1919.

Lectotypus (designated here): MADAGASCAR. Reg. Vakinankaratra [Prov. Antananarivo]: cîme au N d’Ambana , près d’Antsirabe, Ankaratra, rocailles, III.1912, 2000 m, Perrier de la Bâthie 11160 [80] ( K [ K000805466 ]!; isolecto-: P [ P00450175 , P02022202 ]!) . Syntypus: MADAGASCAR: “ Central Madagascar ”, s.d., Baron 4318 ( K [ K000244698 ]!, P [ P00450176 fragm.]!) .

= Brachiaria epacridifolia var. glabra A. Camus in Bull. Mus. Natl. Hist. Nat., sér. 2, 22: 297. 1950. Lectotypus (designated here): MADAGASCAR. Reg. Analamanga [Prov. Antananarivo]: Analabe au N de Tananarive, 1500 m, II.1928, Perrier de la Bâthie 18437 (P [ P01973847 ]!; isolecto-: P [ P01973859 ]!). Syntypus: MADAGASCAR. Reg. Vakinankaratra [Prov. Antananarivo]: Ankaratra, 2000 m, XII.1920, Perrier de la Bâthie 13384 (P [ P01973848 ]!).

Stoloniferous mat-forming perennial, prostrate with ascending flowering culms, to 10 cm high, culms much branched, rooting at nodes, glabrous. Leaf sheath glabrous to pubescent. Ligule a miniscule truncate membrane. Leaf blade lanceolate to ovate, chartaceous, 0.5– 1.5 × 0.1– 0.45 cm, glabrous to pubescent on both sides. Inflorescence racemose, slender, open, 2–10 cm long. Racemes 1–6, 1–5 cm long, decreasing in length upwards, retrorse at maturity, on a common axis 0.5–6 cm long, with no secondary branching, rhachis narrow, glabrous, spikelets not overlapping with adjacent spikelets, paired, on pedicels of uneven length, rarely more than 15 spikelets per synflorescence. Spikelets ovate, apically acute, c. 2 mm long, dark green. Lower glume ½–⅔ as long as spikelet, membranous, acute, 3-veined, glabrous to finely scaberulous or verucculose at maturity, orientation relative to rhachis variable. Upper glume as long as spikelet or slightly shorter, membranous, 5-veined, glabrous to finely scaberulous or verucculose at maturity. Lower floret infertile, palea absent. Lower lemma membranous, 5-veined, glabrous to finely scaberulous or verrucculose at maturity. Upper lemma acute, smooth, shiny, white to yellowish.

Distribution and ecology. – Malagasy endemic restricted to northern, central, and south-eastern highlands, in humid and gallery forest shade and also open areas, on rocks, ericoid vegetation, sides of streams, and secondary vegetation, on laterite, gneiss, and clay, at elevations of 1300–2200 m (F ig. 5).

Notes. – Brachiaria epacridifolia (Stapf) A. Camus is easy to recognise by its distinctive, tidy branches and spikelets, short and somewhat retrorse racemes at maturity, and its cushion habit. Its inflorescences are often poorly developed without clear racemes, justifying an alternative placement in the genus Panicum under a morphological classification system. It is commonly seen in shady forest understory and near forest edges. The mature inflorescences of B. epacridifolia somewhat resemble those of Trichanthecium parvifolium (Lam.) Zuloaga & Morrone but its spikelets are less rounded, and the plant is not glaucous.

The lectotype of Brachiaria epacridifolia designated here [K000805466] is the best preserved original material with notes in Stapf ’s hand. Many of Perrier de la Bâthie’s duplicates at K lack the five-digit collection numbers corresponding to those at P but are instead annotated with a different series of two-digit “provisional” numbers. F or the chosen lectotype its numbers from both series are cited, with the provisional Kew number given in square brackets. None of the original material found for B. epacridifolia var. glabra A. Camus bears any note of this varietal epithet on the sheet; the lectotype designated here [P01973847] is annotated as Panicum epacridifolium Stapf in Camus’ handwriting.

Selected specimens examined. – MADAGASCAR. Reg. Alaotra-Mangoro [Prov. Toamasina]: Lac Alaotra, Jard. Bot. Tananarive 3425 ( P) . Reg. Analamanga [Prov. Antananarivo]: mont Angavokely , VI.1947, Humbert 20844 ( K, P) ; Ankazobe , Ankafobe , endophyte plot AN30, VI.2016, Vorontsova et al. 1923 ( K, TAN) . Reg. Anosy [Prov. Toliara]: massif du Kalambatitra , mont Analatsitendrika , XI.1933, Humbert 11922 ( P) ; mont Itrafanaomby , XII.1933, Humbert 13484 ( P) . Reg. Amoron’i Mania [Prov. Fianarantsoa]: Itremo , Ambatoantrano , III.2014, Nanjarisoa et al. 129a ( K, TAN) . Reg. AIANA [Prov. Antsiranana]: massif du Tsaratanana , plateaux supérieurs et hauts sommets de l’Amboabory à l’Antsianongatalata, XI.1937, Humbert 18373bis ( P) ; montagnes au N de Mangindrano ; jusqu’aux sommets d’Ambohimirahavavy, XI.1951, Humbert & Capuron 25292 ( P) . Reg. Haute Matsiatra [Prov. Fianarantsoa]: Andringitra National Park , VI.1965, Morat 1304 ( P) . Reg. Sofia [Prov. Mahajanga]: Tsaratanana Reserve , Misorobe , walking from camp 2 towards camp 1 and Mangindrano , XI.2017, Vorontsova et al. 2113 ( K, MO, P, TAN) . Reg. Vakinankaratra [Prov. Antananarivo]: Ankaratra, au dessus de Manjakatompo , III.1961, Bosser 15277 ( P) . Reg. Vatovavy [Prov. Fianarantsoa]: Ranomafana , Ifanadiana , I.1964, Bosser 18779 ( P) .