Large crabgrass Digitaria sanguinalis (L.) Scop.
Poaceae (Grass family)
Prostrate to ascending summer annual.
Both leaf surfaces and sheath are densely hairy. Leaves are rolled in the bud and more numerous at the base. Leaves are generally shorter, wider and more tapered than those of most other grasses.
Prostrate to ascending stems may reach 3 feet tall, capable of rooting at the nodes. Mature stems are often compressed in cross-section.
Flowers and fruit
The seedhead is a terminal panicle that consists of a few to several slender, fingerlike branches arranged in a whorl. Each plant is capable of producing thousands of yellowish brown, narrow oval to lance-shaped seeds.
Smooth crabgrass [Digitaria ischaemum (Schreb.) Schreb. ex Muhl.]
Differs by having a smaller stature, hairless to sparsely hairy leaves and sheath, a tuft of long hairs at the collar region and stems that do not root at the nodes.