Trailing Crabgrass

Description

Annual. Culms slender, trailing, branching, 30�50 cm tall, glabrous. Leaf sheaths usually glabrous; leaf blades linear-lanceolate, 2�6 � 0.3�0.7 cm, abaxial surface scabrous, adaxial surface glabrous, pubescent or papillose-pilose at base; ligule 0.75�2 mm. Inflorescence digitate; racemes 2�3(�4), slender, 4�10 cm; spikelets paired, loosely imbricate by about half their length; rachis triquetrous, narrowly winged, ca. 0.6 mm broad, margins smooth or almost so. Spikelets narrowly lanceolate, 2.8�3 mm; lower glume triangular, 0.2�0.3 mm; upper glume narrow, long triangular, 1/3�2/3 as long as spikelet, 1�3-veined, villous throughout; lower lemma as long as spikelet, 5�7-veined, a broad intervein space on either side of midvein, lateral veins very close together near margin, appressed silky pubescent, very rarely with a ciliate fringe, never setose; upper lemma yellowish at maturity, narrowly lanceolate. Anthers 0.5�1 mm. Fl. and fr. summer�autumn. 2n = 18.