Large crabgrass Digitaria sanguinalis (L.) Scop
Life cycle: Annual
Native status: Introduced
Habitat: Turf, crop fields
General description: Prostrate or decumbent growth habit, adventitious rooting at nodes of stems. Long, membranous ligule, stiff hairs on the leaf blade and sheath. Smooth crabgrass is similar, but sheaths and blades much less pubescent. Seedhead consists of 3-5 spikes arranged in a ‘finger-like’ arrangement. Crabgrass is lighter green than turf species, so it is very obvious in lawns.
Key ID traits: Membranous ligule, stiff hairs on blade and sheath.
Similar species: Smooth crabgrass generally is smaller and lacks hairs on stem and sheath.
Miscellaneous: Native to Europe. It is believed to be one of the first cultivated grains, and was brought to US for use as a forage species. Genus name refers to ‘finger-like’ inflorescence. Crabgrass is a bigger problem in ag fields in the southern U.S. than in the Cornbelt due to warmer spring temperatures in the south.