Smooth crabgrass

Description

Panicum (panicgrass) is 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 are often large, annual or perennial grasses, growing to 1–3 m (3 ft 3 in – 9 ft 10 in) tall. The flowers are produced in a well-developed panicle often up to 60 cm (24 in) in length with numerous seeds, which are 1–6 mm (0.039–0.236 in) long and 1–2 mm (0.039–0.079 in) broad. The fruits are developed from a two-flowered spikelet. Only the upper floret of each spikelet is fertile; the lower floret is sterile or staminate. Both glumes are present and well developed. Australia has 29 native and 9 introduced species of Panicum. Well-known Panicum species include Panicum miliaceum (proso millet) and Panicum virgatum (switchgrass).