Panicum crateriferum

HABIT Perennial. Glands sunken crateriform. Culms decumbent; 20–60 cm long; rooting from lower nodes. Culm-internodes 2.5–6 cm long; distally glabrous, or pilose. Culm-nodes brown; pubescent. Lateral branches ample. Leaf-sheaths 0.8–2.5 cm long; mostly shorter than adjacent culm internode; glabrous on surface, or hispid; outer margin hairy. Ligule a ciliate membrane; 0.4 mm long. Collar pubescent. Leaf-blade base symmetrical; with a brief petiole-like connection to sheath; petiole pubescent. Leaf-blades lanceolate; 4–6 cm long; 6–13 mm wide. Leaf-blade midrib indistinct. Leaf-blade venation with obscure cross veins. Leaf-blade surface pilose; sparsely hairy; hairy adaxially, or on both sides; with tubercle-based hairs. Leaf-blade margins ciliate; hairy at base.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 4–6; borne along a central axis; distant; ascending; unilateral; 0.5–3 cm long. Central inflorescence axis 5–10 cm long; glabrous. Rhachis angular; with scattered hairs, or glabrous on surface; scabrous on margins. Raceme-bases hirsute.

Spikelets in pairs. Fertile spikelets sessile and pedicelled. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate, or ovate; dorsally compressed; 2.5–3.1 mm long; 0.8–1.1 mm wide; falling entire.

GLUMES Glumes similar; reaching apex of florets; thinner than fertile lemma. Lower glume lanceolate, or oblong; 1.3–2 mm long; 0.33–0.5 length of spikelet; membranous; without keels; 3(–5) -veined. Lower glume primary vein scabrous. Lower glume surface scabrous; pilose; hairy above; with tubercle-based hairs. Lower glume margins ciliate. Lower glume apex acuminate. Upper glume ovate; 2.1–2.8 mm long; 1 length of spikelet; membranous; without keels; 5(–7) -veined. Upper glume surface hirsute; hairy above. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 2.4–3 mm long; 1 length of spikelet; membranous; glandular (2 glands); 5(–7) -veined; pilose; acute. Palea of lower sterile floret 2.2–2.6 mm long; pilose; adorned on flanks. Fertile lemma elliptic; dorsally compressed; 1.5–2 mm long; indurate; yellow; without keel. Lemma margins involute. Palea involute; indurate.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Mexico.

NOTES Paniceae. Zuloaga 1996.

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