DIGITARIA ISCHAEMUM
27. Digitaria Ischaemum (Schreb.) Muhl. Small Crabgrass, Smooth Crabgrass.
A low, branching, ascending or nearly prostrate annual growing as a weed in lawns, pastures, meadows and waste places.
Leaves rolled in the bud-shoot. Sheath compressed, glabrous or the basal ones sometimes sparsely hairy, pale green, tinted pink or purple, split, with margins hyaline and overlapping. Auricles absent. Collar broad, distinct, with a few flexuous hairs at the margin, pale, often divided. Ligule membranous, 2 to 3 mm. long, obtuse to truncate, slightly undulate, thickened and often tinted at the edges. Blade 2 to 6 mm. wide, 2 to 10 long, flat, cordate at base, sharp-pointed, not ridged, dull green or tinged with purple, sparsely hairy with twisted hairs at base on upper surface; margins glabrous or sparsely ciliate, smooth or scabrous.
D. Ischaemum is distinguished from D. sanguinalis by its smaller size and glabrous and usually purplish sheaths.