GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Panicum exiguum

HABIT Annual; caespitose. Culms decumbent; 10–30 cm long. Culm-internodes 1.5–7 cm long; distally glabrous, or hirsute. Culm-nodes pallid, or brown; pubescent. Lateral branches ample. Leaf-sheaths 1–4 cm long; mostly shorter than adjacent culm internode; hirsute; with tubercle-based hairs; outer margin hairy. Ligule a ciliate membrane; 0.5–1.5 mm long. Collar pubescent. Leaf-blades lanceolate; 2–6 cm long; 2–4 mm wide. Leaf-blade surface pilose; with simple hairs, or tubercle-based hairs. Leaf-blade margins cartilaginous; scabrous; ciliate. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle. Peduncle hirsute above.

Panicle open; pyramidal; effuse; 2.5–8 cm long; 2–6 cm wide. Panicle axis glabrous, or pilose. Panicle branches glabrous, or pilose; bearded in axils.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 2–10 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; acuminate; 2.6–3 mm long; 0.8–1 mm wide; falling entire; readily shedding fertile florets and readily shedding glumes (upper glume).

GLUMES Glumes reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 1.7–2.2 mm long; 0.75–0.8 length of spikelet; membranous; without keels; 5 -veined. Lower glume primary vein scabrous. Lower glume apex acuminate. Upper glume ovate; 1 length of spikelet; membranous; without keels; 7 -veined. Upper glume primary vein scabrous. Upper glume apex acute, or acuminate.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; 7 -veined; acute. Palea of lower sterile floret 1.2–1.7 mm long. Fertile lemma elliptic; dorsally compressed; 1.4–2 mm long; indurate; black; without keel; 5–7 -veined. Lemma margins involute. Palea involute; indurate.

FRUIT Caryopsis with adherent pericarp; 1.1–1.4 mm long. Embryo 0.5 length of caryopsis. Hilum punctiform.

DISTRIBUTION South America: western South America, Brazil, and southern South America.

NOTES Paniceae. Fl Paraguay 1995.

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