Panicum hirstii

HABIT Perennial. Culms erect, or geniculately ascending; 55–80 cm long. Culm-internodes distally glabrous. Lateral branches sparse. Leaves all alike. Leaf-sheaths mostly shorter than adjacent culm internode; glabrous on surface; outer margin glabrous, or hairy. Ligule a fringe of hairs; 0.5 mm long. Leaf-blades erect, or ascending; 4.5–11 cm long; 3–5.5 mm wide. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 4.5–9 cm long; 0.5 cm wide. Primary panicle branches appressed; 1–2.5 cm long. Panicle branches scaberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 1.8–2.1 mm long; falling entire.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.5–0.8 mm long; 0.33 length of spikelet; membranous; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex obtuse. Upper glume elliptic; 0.9 length of spikelet; membranous; without keels; 7 -veined. Upper glume apex obtuse.

FLORETS Basal sterile florets barren. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 7 -veined. Fertile lemma elliptic; dorsally compressed; 1.8–2.1 mm long; indurate; pallid, or yellow; without keel. Lemma margins involute. Lemma apex acute. Palea involute; indurate.

DISTRIBUTION North America: northeast USA.

NOTES Paniceae. Swallen 2004.

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