Axonopus arsenei

HABIT Perennial. Culms erect, or geniculately ascending; 15–75 cm long; 1–2 mm diam.; 1–2 -noded. Culm-internodes elliptical in section. Culm-nodes pubescent. Leaves mostly basal. Leaf-sheaths 4–20 cm long. Ligule a ciliolate membrane; 0.3–0.4 mm long. Leaf-blades ascending; 3–15 cm long; 5–8 mm wide. Leaf-blade surface pilose; densely hairy; hairy adaxially. Leaf-blade apex obtuse; soon splitting.

INFLORESCENCE Inflorescence composed of racemes; with 1–2 peduncles per sheath. Peduncle straight, or nodding; 30–60 cm long.

Racemes 2–4; paired, or digitate; ascending; unilateral; 4–12 cm long. Central inflorescence axis 0–3 cm long. Rhachis angular; 0.5–0.7 mm wide; glabrous on surface; smooth on margins, or scabrous on margins; glabrous on margins. Spikelet packing adaxial; 3–4 spikelets per cm. Raceme-bases brief; pubescent, or pilose.

Spikelets appressed; solitary. Fertile spikelets sessile, or pedicelled. Pedicels 0–0.3 mm long; tip cupuliform.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; acute; 3–3.1 mm long; 1–1.1 mm wide; falling entire.

GLUMES Glumes one the lower absent or obscure; reaching apex of florets; thinner than fertile lemma. Upper glume 1 length of spikelet; membranous; mid-green, or purple; 3–5 -veined. Upper glume surface pubescent; hairy between veins.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; 1.1 length of fertile lemma; 1 length of spikelet; pallid; 3–5 -veined; pubescent; hairy between veins. Fertile lemma ovate; 2.6–2.7 mm long; indurate; yellow; without keel. Lemma margins involute. Palea involute; indurate.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Paniceae. Black 1994.

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