Panicum philadelphicum

HABIT Annual; caespitose. Culms erect; slender; 20–50(–60) cm long. Culm-internodes distally hirsute, or hispid. Leaf-sheaths hispid; with tubercle-based hairs. Ligule a fringe of hairs; 0.5–1.5 mm long. Leaf-blades 5–15 cm long; 2–7 mm wide; light green. Leaf-blade surface glabrous to hispid; hairy on both sides. Leaf-blade margins tuberculate-ciliate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 7–15 cm long; 0.25–0.33 of culm length; with spikelets clustered towards branch tips. Primary panicle branches ascending, or spreading; 1 -nate. Panicle axis glabrous, or pubescent. Panicle branches stiff; bearded in axils.

Spikelets appressed; in pairs. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; acute; 1.2–2(–2.2) mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.33 length of spikelet; membranous; without keels; 5 -veined. Lower glume apex acute. Upper glume elliptic; 1 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 5 -veined; acute. Fertile lemma elliptic; dorsally compressed; 1.3–1.7 mm long; indurate; shiny; without keel. Lemma margins involute. Lemma apex acute. Palea involute; indurate.

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

NOTES Paniceae. Gr Texas 1994.

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