[1] It is native to Europe and Asia, but it is known throughout much of the warm temperate world as an introduced species and often a common roadside and garden weed.

The flowers of smooth crabgrass grow in clusters of 2 to 6, forming spike-like shapes about 1½ to 4 inches long, arranged like fingers at the tips of branching stems.

The small bracts at the base of each spikelet are uneven in size, with one being almost invisible or absent and the other covered in short hairs.

The leaf sheaths are open in the front, sometimes with a few long hairs near the top but mostly hairless, and they loosely wrap around the stem, often having a ridge along the back.

[3] They grow in terrestrial regions and can be seen in central Europe and Japan, Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont.