Smooth crabgrass

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Smooth crabgrass leaf

Smooth crabgrass ligule

Smooth crabgrass

Smooth crabgrass spikelets

Smooth crabgrass

Smooth crabgrass

Smooth crabgrass

Morphology

Culm

Ascending or erect from spreading bases, usually bent, slender.

Blades

Flat, .6 to 6+ inches long, 1/10 to 2/5 inch wide, midrib absent, often purplish, glabrous to very sparsely hairy near ligule.

Sheath

Keeled, glabrous or with sparse hairs on upper margins.

Ligule

Membranous, short

Inflorescence

Racemes, 2-8, spike-like, 1.6 to 6 inches long, extending in different directions from a common point, terminating main inflorescence axis; rachis flattened, less than 1/20 inch wide, thin-winged.

Spikelets

Lanceolate-elliptic, 1/16 to 1/12 inch long, grouped in 2 rows on 1 side of raceme branch axis, 1-flowered, sessile or short-stalked, becoming dark brown or purplish-black; first glume absent or underdeveloped; second glume elliptic, 1/16 to 1/12 inch long, sparsely to densely pubescent with minute gland-tipped hairs; tip sharply pointed; sterile lemma about equal to second glume, 5-nerved, pointed; fertile lemma ovate-elliptic, pubescent; tip sharply pointed; margin thin, transparent.

Ecology

Habitat

Moist, disturbed sites, stream banks, lake and pond margins, roadsides, open woods, fields, gardens, waste areas.

Distribution

Principally east 1/2 of Kansas.

Additional Notes