Family Homeowner lawns to farmer fields, these guys cover them all.
Large crabgrass is larger, more hairy, and possibly adapted to drier habitats than smooth crabgrass.
Large crabgrass is often called hairy crabgrass. Smooth crabgrass is more likely to be home lawns, not to mention your favorite golf course. Both species have a membranous ligule. If you get confused with this just follow the hairs to large crabgrass. Large crabgrass has what is called a decumbent habit, meaning the stems get lazy and grow horizontally instead of straight up.