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 rhizogonum

HABIT Perennial. Culms rambling; 10–50 cm long; rooting from lower nodes. Culm-internodes elliptical in section; 2–7 cm long; distally glabrous, or pubescent. Leaf-sheaths 1–3.5 cm long; mostly shorter than adjacent culm internode; glabrous on surface; outer margin hairy. Ligule a ciliate membrane; 0.3–0.6 mm long. Leaf-blade base broadly rounded; asymmetrical; with a false petiole. Leaf-blades lanceolate, or ovate; 4–9 cm long; 9–22 mm wide; mid-green and purple; discolorous with last colour beneath. Leaf-blade midrib evident. Leaf-blade surface glabrous, or pubescent; sparsely hairy. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence a panicle; terminal and axillary. Axillary inflorescences different from terminal (cleistogamus); compact.

Panicle open; ovate; 1.5–7 cm long; 1–6 cm wide. Panicle axis scabrous; glabrous, or hispid. Panicle branches flexuous; scabrous; glabrous, or hispid; pubescent in axils.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels angular; smooth, or scaberulous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 2.6–3.3 mm long; 1.4–1.6 mm wide; falling entire.

GLUMES Glumes reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 1.6–2.7 mm long; 0.5–0.75 length of spikelet; membranous; without keels; 3 -veined. Lower glume apex acute. Upper glume ovate; 1 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; 5 -veined; acute. Fertile lemma elliptic; dorsally compressed; 2.3–2.7 mm long; indurate; yellow; shiny; without keel; 5 -veined. Lemma surface papillose. Lemma margins involute. Lemma apex apiculate. Palea involute; indurate.

FRUIT Caryopsis with adherent pericarp; ovoid; 1.6–1.8 mm long. Embryo 0.5 length of caryopsis. Hilum elliptic.

DISTRIBUTION South America: Brazil and southern South America.

NOTES Paniceae. Zuloaga 1995.

ADDITIONAL CHARACTERS Cleistogamous spikelets pubescent.

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