GrassBase - The Online World Grass Flora

Descriptions

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

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

Panicum penicillatum

HABIT Perennial. Culms leaning, or scandent; 500–1000 cm long; rooting from lower nodes. Culm-internodes terete; solid; 8–18 cm long; distally glabrous. Culm-nodes brown; glabrous, or pubescent. Lateral branches ample; arising from lower culm. Leaf-sheaths 10–14 cm long; glabrous on surface, or pilose; with tubercle-based hairs; outer margin hairy. Ligule a ciliate membrane; 0.5 mm long. Collar dark; glabrous, or pubescent. Leaf-blade base asymmetrical; with a false petiole; petiole pubescent. Leaf-blades lanceolate; 18–32 cm long; 12–32 mm wide. Leaf-blade surface glabrous, or pubescent. Leaf-blade margins scabrous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle. Peduncle glabrous.

Panicle open; ovate; effuse; 30–45 cm long; 20–40 cm wide. Panicle axis smooth, or scaberulous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels angular; flexuous; scaberulous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 3–4.2 mm long; 1.1–1.4 mm wide; falling entire.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 2.8–3.6 mm long; 1 length of spikelet; membranous; without keels; 3–5 -veined. Lower glume surface pubescent; hairy above; inner surface scabrous. Lower glume apex acuminate. Upper glume elliptic; 3–4 mm long; 1 length of spikelet; membranous; without keels; (7–)9–11 -veined. Upper glume lateral veins prominent. Upper glume surface pubescent; hairy above; inner surface pubescent. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 9–11 -veined; prominently veined; acute. Fertile lemma ovate; dorsally compressed; 3.2–3.7 mm long; 1–1.3 mm wide; indurate; yellow; without keel. Lemma surface papillose. Lemma margins involute; pubescent. Lemma apex apiculate; pubescent. Palea involute; indurate.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 2.2–2.4 mm long. Embryo 0.5 length of caryopsis. Hilum punctiform.

DISTRIBUTION South America: Brazil.

NOTES Paniceae. Zuloaga 2004.

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