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 petropolitanum

HABIT Perennial. Stolons present. Culms geniculately ascending; 10–25 cm long; rooting from lower nodes. Culm-internodes terete, or elliptical in section; 1–4 cm long; distally glabrous. Culm-nodes constricted; brown; glabrous, or pubescent, or bearded. Lateral branches ample. Leaf-sheaths 1.5–5.5 cm long; longer than adjacent culm internode; glabrous on surface; outer margin hairy. Ligule a ciliate membrane; 0.2 mm long. Collar glabrous. Leaf-blades linear, or lanceolate; 2–5 cm long; 1–3 mm wide. Leaf-blade margins scaberulous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle. Peduncle 8–16 cm long.

Panicle open; ovate; effuse; 2–4 cm long; 1–3.5 cm wide. Primary panicle branches not whorled. Panicle axis glabrous. Panicle branches glabrous; glabrous in axils.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–7 mm long; scaberulous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 2.4–2.6 mm long; 0.9 mm wide; falling entire.

GLUMES Glumes similar; reaching apex of florets; thinner than fertile lemma. Lower glume lanceolate; not clasping; 1.8–2 mm long; 0.75 length of spikelet; membranous; without keels; 1(–3) -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent, or obscure. Lower glume apex acute. Upper glume elliptic; 1 length of spikelet; membranous; without keels; (7–)9 -veined. 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; 9 -veined; acute. Palea of lower sterile floret 1.5 mm long. Fertile lemma elliptic; dorsally compressed; 2.3 mm long; 0.7 mm wide; indurate; shiny; without keel. Lemma margins involute. Lemma apex apiculate. Palea involute; indurate.

FLOWER Anthers 3; 1 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 1.2 mm long. Embryo 0.33 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.