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 cumbucanum

HABIT Perennial. Rhizomes short. Culms decumbent; 15–35 cm long. Culm-internodes 1–2.8 cm long; distally hispid. Culm-nodes pubescent. Lateral branches ample; arising from upper culm. Leaf-sheaths 1–2 cm long; glabrous on surface, or hispid; outer margin hairy. Ligule a ciliate membrane; 0.4–0.6 mm long. Collar pubescent. Leaf-blade base amplexicaul. Leaf-blades ascending; lanceolate; 1–3 cm long; 3–6 mm wide; stiff. Leaf-blade midrib conspicuous. Leaf-blade surface pubescent; hairy on both sides. Leaf-blade margins scaberulous; ciliate; hairy at base. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle; exserted, or embraced at base by subtending leaf.

Panicle open; ovate; 1–2.5 cm long; 1–2 cm wide; bearing few spikelets. Panicle axis pubescent. Panicle branches eglandular; pubescent; pubescent in axils.

Spikelets solitary, or in pairs. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 1.9–2.4 mm long; 0.6–0.8 mm wide; falling entire. Rhachilla internodes elongated between glumes. Rhachilla elongation 0.3 mm long.

GLUMES Glumes similar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; not clasping; 1–1.3 mm long; 0.5 length of spikelet; membranous; without keels; 3 -veined. Lower glume surface glabrous, or pubescent. Lower glume apex acute. Upper glume elliptic; 1.3–1.9 mm long; 0.66–0.75 length of spikelet; membranous; without keels; 7–9 -veined. Upper glume surface pubescent. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 7–9 -veined; glabrous, or pubescent; acute. Palea of lower sterile floret 1.3–1.5 mm long; 0.75 length of lemma. Fertile lemma elliptic; dorsally compressed; 1.5–1.8 mm long; 0.5–0.7 mm wide; indurate; pallid; without keel; 5 -veined. Lemma surface pubescent. Lemma margins involute. Lemma apex acute. Palea involute; indurate.

FLOWER Anthers 3; 0.9 mm long; purple.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 1.2–1.5 mm long. Embryo 0.4–0.5 length of caryopsis. Hilum punctiform.

DISTRIBUTION South America: Brazil.

NOTES Paniceae. Zuloaga 1994.

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