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DescriptionThis introduced grass is a summer annual about 1-3' long. It develops several branching culms at the base; the lower branches of the culms tend to sprawl across the ground, while their upper branches are more erect. The culms are light green, terete, and glabrous, although they are mostly covered by the sheaths. The blades of the alternate leaves are up to 6" long and nearly ½" across; they are dull light green, entire or slightly curly along the margins, and often hairy toward the base. The sheaths are light green, finely ribbed, shiny or dull, and hairy. Each upper culm terminates in 2-10 finger-like racemes up to 8" long; these racemes spread outward from a short stalk and they are narrow and straight. The central stalk (rachis) of each raceme is light green, flattened, and about 1 mm. across. There are many pairs of one-flowered spikelets along the length of each raceme; they occur along only one side of the flattened stalk. Each ovoid spikelet is light green to brownish green, flattened, and about 3 mm. long. It consists of 2 lemmas about 3 mm. long and 2 glumes; one glume is about 1/3 to 1/2 as long as the lemmas, while the other glume is tiny and insignificant. The lemmas enclose a single developing grain. The blooming period occurs from mid-summer to early fall. Each grain is ovoid and flattened like the lemmas. The root system is fibrous; sometimes the nodes of the lower culms will form new fibrous roots. Common Crabgrass often forms colonies.