Panicum vaseyanum

HABIT Annual. Culms decumbent; 50–70 cm long; rooting from lower nodes. Leaf-sheaths inflated. Ligule a ciliolate membrane; 1–2 mm long. Leaf-blades 5–10 cm long; 3–8 mm wide.

INFLORESCENCE Inflorescence a panicle; terminal and axillary; subtended by an inflated leaf-sheath; embraced at base by subtending leaf.

Panicle open; lanceolate; 4–7 cm long; 1 cm wide. Primary panicle branches ascending.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 3–4 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; subacute; 2–2.6 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.4–0.8 mm long; 0.25–0.33 length of spikelet; membranous; without keels. Lower glume apex obtuse, or acute. Upper glume ovate; 1 length of spikelet; membranous; without keels. 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; acute. Fertile lemma elliptic; dorsally compressed; 2–2.6 mm long; indurate; pallid, or light green, or light brown; shiny; without keel. Lemma margins involute. Lemma apex acute. Palea involute; indurate.

DISTRIBUTION North America: Mexico.

NOTES Paniceae. Fl Nov Gal 1994.

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