Digitaria sellowii

HABIT Perennial; caespitose. Rhizomes short, or elongated; scaly; hairy. Culms erect; 25–150 cm long; 3–8 -noded. Culm-internodes distally glabrous. Culm-nodes brown; glabrous, or pubescent. Lateral branches sparse. Leaf-sheaths 3–25 cm long; glabrous on surface, or pilose; with tubercle-based hairs. Ligule an eciliate membrane; 2–4 mm long; erose. Leaf-blades 2–20 cm long; 2–10 mm wide. Leaf-blade surface glabrous, or pubescent; hairy on both sides. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 4–30; borne along a central axis; unilateral; 2–12 cm long. Central inflorescence axis 8–30 cm long. Rhachis angular; 0.3–0.5 mm wide; scabrous on margins.

Spikelets in pairs. Fertile spikelets sessile and pedicelled; 2 in the cluster.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; acute; 3.75–5.5 mm long; with hairs extending 1–3 mm beyond apex; falling entire. Rhachilla internodes elongated below basal sterile floret. Rhachilla elongation 0.3–0.7 mm long.

GLUMES Glumes two; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.3–0.9 mm long; 0.1 length of spikelet; hyaline; 0–1 -veined. Lower glume lateral veins absent. Lower glume apex truncate, or obtuse. Upper glume lanceolate; 2.75–5 mm long; 0.75–0.9 length of spikelet; membranous; without keels; 3–5 -veined. Upper glume surface villous; hairy between veins. Upper glume hairs white, or tawny; 3–4 mm long. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret elliptic; 4–5.5 mm long; 1 length of spikelet; membranous; 5–7 -veined; with equidistant veins; glabrous, or puberulous; hairy between veins; ciliate on margins, or villous on margins; acuminate. Fertile lemma elliptic; 2.75–4.5 mm long; 0.7–0.9 mm wide; cartilaginous; much thinner on margins; dark brown; without keel. Lemma surface striate. Lemma margins flat; covering most of palea. Lemma apex acuminate. Palea 1 length of lemma; cartilaginous.

FLOWER Lodicules 2; 0.5 mm long. Anthers 3; 0.5–1.5 mm long.

FRUIT Caryopsis with adherent pericarp; ovoid; 1.3–2.2 mm long. Embryo 0.33–0.5 length of caryopsis. Hilum punctiform. Disseminule comprising a spikelet.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, Caribbean, western South America, Brazil, and southern South America.

NOTES Paniceae. Fl Mesoamer 2012.

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