Alopecurus carolinianus

HABIT Annual; caespitose. Culms 10–50 cm long. Culm-internodes distally glabrous. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 3.5–7 mm long. Leaf-blades 3–15 cm long; 1–4 mm wide. Leaf-blade surface smooth, or scaberulous.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear; 2–6 cm long; 0.4–0.6 cm wide. Primary panicle branches accrescent to a central axis; with evident branchlets on axis. Panicle axis with rounded ribs.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels oblong.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 1.8–3 mm long; falling entire.

GLUMES Glumes connate along margins below; 0.25–0.33 of their length connate; similar; reaching apex of florets. Lower glume ovate; 1.8–3 mm long; 1 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume primary vein ciliate. Lower glume margins ciliate. Lower glume apex acute. Upper glume ovate; 1.8–3 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein ciliate. Upper glume margins ciliate. Upper glume apex acute.

FLORETS Fertile lemma ovate; 1.8–2 mm long; membranous; keeled; 5 -veined. Lemma margins connate below. Lemma apex obtuse; awned; 1 -awned. Principal lemma awn dorsal; arising 0.1–0.2 way up back of lemma; geniculate; 3–5 mm long overall; with twisted column. Palea absent or minute.

FLOWER Lodicules absent. Anthers 3; 0.3–0.5 mm long. Stigmas protogynous; terminally exserted; pubescent. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; 1–1.4 mm long. Embryo 0.25 length of caryopsis. Hilum punctiform. Disseminule comprising a spikelet.

DISTRIBUTION North America: western Canada, northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, and southeast USA.

NOTES Aveneae. Gr Tex 1993.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.