Megathyrsus maximus

M. maximus is a robust, highly variable grass. It is a loosely to densely tufted perennial.
Vegetative morphology
M. maximus grows in densely tufted clumps with very short rhizomes;erect stems which are cylindrical, slightly flattened at the base, streaked with white wax at the nodes and internodes;glabrous internodes, hairy nodes, infrequently branched, up to 2.5 m. M. maximus is tall, usually 1-2 m tall. Light green, green or bluish-green leaves. The lower nodes of the stolons are rooted and can form new plants (Alves and Xavier, 1986).
Culms (25-)75-200(-450) cm high, erect from a shortly pubescent base or geniculately ascending and rooting at the lower nodes, slender to robust, branched or simple, glabrous to hispid or pilose, the lower nodes glabrous or bearded with soft, spreading hairs. Leaf blades linear to narrowly lanceolate, (6-)12-40(-100) cm long, (4-)12-35 mm wide, narrowed or straight at the base, flat membranous or herbaceous, glabrous or sparsely pilose to pubescent, acuminate (after Clayton et al., 1974).
Floral morphology
M. maximus has terminal, ovoid racemose panicles, 15-65 cm long, with brick-red spikelets when mature;spikelets roughly 3.5 mm long (Alves and Xavier, 1986).
Panicle oblong or pyramidal, 12-45(-60) cm long, usually much branched, the branches ascending to spreading, the lowest arranged in a whorl;pedicels and secondary branches fine and flexuous to fairly stiff and contracted. Spikelets oblong, (2.5-)3-4.5(-5) mm long, rounded on the back, glabrous or pubescent, blunt or acute, occasionally overtopped by long hairs from the tip of the pedicel;lower glume broadly ovate, one-third to one-half the length of the spikelet, 3-nerved, obtuse or acute;upper glume ovate-oblong, 5-nerved, acute;lower lemma ovate-oblong, 5-nerved;male rarely sterile, its palea well developed;upper lemma and palea conspicuously transversely rugose (after Clayton et al., 1974). The ligule is membranous with a ciliate margin, 1-3 mm long (Wagner et al., 1999).
[Note: Figures indicate normal range of sizes;those in brackets indicate the extremes of variation possible.]