Panicum's a large genus of about 450 species of grasses native throughout the tropical regions of the world, with a few species extending into the northern temperate zone. They're often large, annual or perennial grasses, growing to 1-3 m tall. The flowers are produced in a well-developed panicle often up to 60 cm in length with numerous seeds, which are 1-6 mm long and 1-2 mm broad. The fruits are developed from a two-flowered spikelet. Only the upper floret of each spikelet's fertile; the low… (More on Panicum)