Panicum trichocladum K. Schum.

Vorontsova, Maria S., 2018, Revision of the group previously known as Panicum L. (Poaceae: Panicoideae) in Madagascar, Candollea 73 (2), pp. 143-186 : 178-180

27. Panicum trichocladum K. Schum. in Engl., Pflanzenw. OstAfrikas, C: 103. 1895.

Lectotypus (designated here): TANZANIA: Kilimanjaro, s.d., H. Meyer 140 ( B [ B100715462 ] image seen; isolectotype: US [ US00140067 ] image seen) . Syntypus: TANZANIA: Usambara , s.d., Volkens 69 ( B †, US [ US00140067 ] image seen, BR [ BR0000008766779 ] image seen) .

Scrambling ascending perennial, rhizomatous, 1.5– 2 m tall, the culms branching, glabrous or sometimes pubescent on the nodes. Leaf sheaths glabrous to finely pubescent. Ligule a ciliolate membrane. Leaf blades linear to lanceolate, flat, chartaceous, 3–15 × 0.5–1.5 cm, drying green-brown, rounded at the base and acuminate at the tip, glabrous to finely pubescent on both sides. Panicles terminal, partly or fully exserted, 5–15 cm long, ovate, diffuse, the branches filiform, flexuous, with long white cilia subtending the spikelet, the pedicels 3–10 mm long. Spikelets oblong, apically rounded to acute, c. 3 mm long, with poorly visible veins, green to purple, partly open at maturity. Lower glume 1/6–¼ as long as the spikelet, membranous, with no veins, glabrous. Upper glume as long as the spikelet, herbaceous, 5-veined, glabrous. Lower floret male, with palea. Lower lemma herbaceous, 5-veined, glabrous. Upper lemma smooth, shiny, pale.

Distribution and ecology. – Tropical African species introduced to South America and Asia, and common on the Comoros. Sometimes collected in northern Madagascar, with a single weedy record from Fianarantsoa. Humid disturbed areas, often near human habitation, 50–1000 m ( Fig. 16A ).

Notes. – This species can be recognised by its wiry flexuous inflorescence branches, and by long white trichomes usually subtending the spikelet. It seems likely that this species is introduced in Madagascar.

This species is illustrated in BOSSER (1969: Fig. 127a-d).

Additional material examined. – MADAGASCAR. Prov. Antsiranana: Nosy Be , VII.1850, Boivin 1962bis ( P [ P02608269 ]) ; montagne d’Ambre , Joffreville , VII.1953, Bosser 5448 ( P [ P02608274 ]) ; Nosy Be, Ambatoloaka , VIII.1959, Bosser 13220 ( P [ P02608268 ]) ; camp d’Ambre , IV.1933, Perrier de la Bâthie 19303 ( P [ P02608270 ]) ; Nosy Be, Passandana , 18.VII.1840, Perville 299 ( K [ K000805601 ], P [ P02608266 ]) ; Nosy Be, Hellville , 11.IX.1912, Viguier & Humbert 124 ( P [ P02608273 ]) . Prov. Fianarantsoa: RN25 from Irondro to Ambolotara , 21°23'12"S 47°56'19"E, 4.XI.2011, Vorontsova et al. 705 ( K, TAN) .

Figures

Fig. 16. – Distribution maps. A. Panicum subalbidum Kunth (stars), P. subhystrix A. Camus (triangles), P. trichocladum K. Schum. (circles) and P. voeltzkowii Mez (squares); B. Panicum vohitrense A. Camus (stars), Trichanthecium brazzavillense (Franch.) Zuloaga & Morrone (triangles), T. parvifolium (Lam.) Zuloaga & Morrone (circles) and Urochloa maxima (Jacq.) R.D. Webster (squares).