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 stigmosum

HABIT Perennial. Culms leaning; 50–100 cm long. Culm-internodes elliptical in section; 4–19 cm long; glandular; distally glabrous. Culm-nodes constricted; brown; glabrous, or pubescent. Lateral branches ample; arising from lower culm and upper culm. Leaf-sheaths 3–11 cm long; glandular; glabrous on surface, or hispid; outer margin hairy. Ligule a ciliate membrane; 1–1.6 mm long. Collar pubescent, or pilose. Leaf-blade base broadly rounded, or cordate. Leaf-blades lanceolate; 10–22 cm long; 10–22 mm wide; eglandular, or glandular. Leaf-blade surface glabrous, or pilose; sparsely hairy; hairy adaxially, or on both sides. Leaf-blade margins scabrous; ciliate. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle. Peduncle 9–34 cm long; glandular; glabrous, or pilose above.

Panicle open; ovate; effuse; 9–21 cm long; 6–15 cm wide. Panicle axis glabrous, or pilose. Panicle branches flexuous; glandular; scaberulous; pubescent in axils.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels clavate; scabrous; bearing a few hairs, or ciliate.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic, or oblong; dorsally compressed; 2.4–3.2 mm long; 1.1–1.3 mm wide; falling entire. Rhachilla internodes elongated between glumes.

GLUMES Glumes similar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; clasping; 1.1–1.8 mm long; 0.5–0.75 length of spikelet; membranous; without keels; (1–)3 -veined. Lower glume apex acute. Upper glume elliptic; 2–2.4 mm long; 0.9 length of spikelet; membranous; without keels; 7–9 -veined. Upper glume lateral veins distinct. Upper glume apex acute.

FLORETS Basal sterile florets male, or barren; with palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 7–9 -veined; acute. Palea of lower sterile floret 1 length of lemma; pilose; adorned on flanks. Fertile lemma elliptic; dorsally compressed; 1.9–2.1 mm long; indurate; yellow; without keel. Lemma surface papillose. Lemma margins involute. Lemma apex acuminate. Palea involute; indurate.

FLOWER Anthers 3; 0.7 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 1.3 mm long. Embryo 0.33 length of caryopsis. Hilum punctiform.

DISTRIBUTION South America: western South America and Brazil.

NOTES Paniceae. Zuloaga 1994.

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