Large Crabgrass

A member of the grass family, large crabgrass (Digitaria sanguinalis) is purplish or green and has very hairy leaves and sheaths. Leaves are 1/4 to 1/3 inch (6 to 8 mm) wide and 2 to 6 inches (5 to 15 cm) long.
Seedling Description

The leaf sheaths of large crabgrass seedlings are tinged purple and are covered with long, stiff hairs. The ligule is membranous, flat at the top, and smooth. Auricles are absent. The first leaf is only about twice as long as it is wide. It is tinged light purple and has a white stripe running down the center and a whitish vein at the margin. Both sides have silky, shiny hairs. Leaves taper to a point and have many veins and rough margins. The youngest leaf is rolled in the bud shoot.

Biology
A member of the grass family, large crabgrass is purplish or green and has very hairy leaves and sheaths. Leaves are ¼ to 1/3 inch (6 to 8 mm) wide and 2 to 6 inches (5 to 15 cm) long. In most areas of the country, large crabgrass is an annual, but in some areas it grows like a perennial-rooting at the nodes and forming mats in moist soils. These mats occasionally grow upright.


Large crabgrass reproduces by tillers and seeds, a single plant producing as many as 700 tillers and 150,000 seeds. Plants can produce seeds at mowing heights as low as ¼ inch (6 mm). If top growth is periodically mowed, two to three seed crops may form in a single growing season.