Megathyrsus maximus

Megathyrsus maximus is a robust, densely tufted perennial grass of the Poaceae family growing 1-3 m tall in vigorous clumps from a knotty, shortly rhizomatous base. Culms are erect or geniculately ascending, stout, hollow, smooth and often glaucous, with conspicuously hairy nodes. Leaf blades are linear, flat, 30-80 cm long and 1-3.5 cm wide, with a thickened pale midrib, scaberulous margins and a typically pubescent base; leaf sheaths are keeled and usually densely white-hairy. The ligule is a short ciliate membrane 2-5 mm tall. The inflorescence is a large open pyramidal panicle 20-50 cm long with whorled lower branches that themselves bear secondary branchlets; the lowest whorl is often densely hairy in the axils. Spikelets are oblong-ellipsoid, 2.5-3.5 mm long, glabrous, often purplish-tinged and two-flowered with the lower floret staminate or sterile and the upper bisexual; the upper lemma is hardened, transversely rugulose and shiny at maturity. Native to tropical Africa and the Arabian Peninsula and widely introduced as a pasture grass throughout the global tropics and subtropics, where it is highly invasive in many regions.