Panicum boreale

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 30–65 cm long. Culm-internodes distally glabrous. Culm-nodes glabrous. Lateral branches sparse. Leaves heterophyllous with a basal winter rosette. Leaf-sheaths glabrous on surface; outer margin hairy. Ligule a ciliate membrane; 0.5 mm long. Leaf-blade base broadly rounded. Leaf-blades erect, or ascending; 6–12 cm long; 6–14 mm wide. Leaf-blade surface glabrous. Leaf-blade margins glabrous, or ciliate; hairy at base. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 5–10 cm long. Primary panicle branches ascending, or spreading.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; subacute; 2–2.1 mm long; 1 mm wide; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.25–0.33 length of spikelet; membranous; without keels; 3 -veined. Lower glume apex acute. Upper glume ovate; 1 length of spikelet; membranous; without keels; 7 -veined. Upper glume surface pubescent. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; 7 -veined; glabrous, or pubescent; acute. Fertile lemma elliptic; dorsally compressed; 1.9 mm long; indurate; without keel. Lemma margins involute. Palea involute; indurate.

FLOWER Anthers 0.8–1 mm long.

DISTRIBUTION North America: eastern Canada, north-central USA, northeast USA, and southeast USA.

NOTES Paniceae. Gr Indiana 1994.

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