Cenchrus palmeri

HABIT Annual; culms solitary. Culms 9–35 cm long. Leaf-sheaths puberulous; outer margin hairy. Leaf-sheath oral hairs ciliate. Ligule a fringe of hairs; 1.3–2.3 mm long. Leaf-blades 4.4–10 cm long; 3.8–6.8 mm wide. Leaf-blade surface puberulous.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear; 2–4.2 cm long. Primary panicle branches accrescent to a central axis; burrs 1–4 in number; with sessile scars on axis. Panicle axis angular; scaberulous; bearing deciduous spikelet clusters.

Spikelets subtended by an involucre. Fertile spikelets sessile; 4–8 in the cluster. Involucre composed of bristles; connate into a cup below; globose; 11.5–18.5 mm long; base obconical. Involucral bristles deciduous with the fertile spikelets; numerous; emerging irregularly from body of a burr; 40–65 in principal whorl; 5.8–11 mm long; terete (dark coloured); rigid; retrorsely scaberulous; pubescent; spinose.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; acuminate; 5.2–7.3 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes one the lower absent or obscure; shorter than spikelet; thinner than fertile lemma. Upper glume ovate; 4.5–6.4 mm long; 0.9 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret ovate; 4.5–6.5 mm long; 0.9 length of spikelet; membranous; 5–7 -veined; acute. Fertile lemma ovate; 5.2–7.1 mm long; coriaceous; much thinner on margins; without keel; 3 -veined. Lemma margins flat. Lemma apex obtuse. Palea coriaceous.

FLOWER Anthers 1.7–2.1 mm long.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Mexico.

NOTES Paniceae. De Lisle.

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