Page author: Don Knoke
Digitaria ischaemum
smooth crabgrass

Distribution: Most of southern Canada, and all of the United States except the extreme southeast and southwest.

Habitat: Lawns, roadsides and wastland, usually where moist.

Flowers: July - September

Origin: Introduced from Eurasia

Growth Duration: Annual

Conservation Status: Not of concern


Spreading annual, tending to root at the nodes, the culms hollow, glabrous, 1-3 dm. tall.


Sheaths open; ligules truncate, 1-2 mm. long; blades flat, 2-4 mm. broad, glabrous or slightly scabrous, the margins turned upward at the base and fused with the ligule.


Inflorescence of 3-6 digitate racemes 3-7 cm. long; articulate below the glumes; spikelets 2-flowered, the lower sterile, paired on one side of a triangular rachis; first glume translucent and semicircular, barely 0.3 mm. long; second glume and sterile lemma about 2 mm. long; fertile lemma and palea about equal, hardened, smooth; stamens 3.

Accepted Name:
Digitaria ischaemum (Schreb.) Muhl.
Publication: Descr. Gram. 131. 1817.

Synonyms & Misapplications:
Digitaria ischaemum (Schreb.) Muhl. var. mississippiensis (Gatt.) Fernald
Panicum ischaemum Schreb.
Syntherisma ischaemum (Schreb.) Nash
Additional Resources:

PNW Herbaria: Specimen records of Digitaria ischaemum in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Digitaria ischaemum checklist entry.

E-Flora BC: Digitaria ischaemum atlas page.

CalPhotos: Digitaria ischaemum photos.

USDA Plants: Digitaria ischaemum information.

7 photographs:
Group by