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 hylaeicum

HABIT Perennial. Culms rambling; robust; 100–200 cm long; without nodal roots, or rooting from lower nodes. Culm-internodes terete; 4–20 cm long. Culm-nodes purple; glabrous. Leaf-sheaths 3.5–10 cm long; glabrous on surface, or pilose; outer margin hairy. Ligule a ciliolate membrane; 0.3–0.7 mm long. Leaf-blade base amplexicaul; with a brief petiole-like connection to sheath. Leaf-blades lanceolate, or ovate; 7–26 cm long; 10–30 mm wide. Leaf-blade venation with obscure cross veins. Leaf-blade surface glabrous, or pubescent; hairy on both sides. Leaf-blade margins ciliate; hairy at base. Leaf-blade apex attenuate.

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

Panicle open; ovate; 10–32 cm long; 4.5–17.5 cm wide; contracted about secondary branches. Primary panicle branches ascending, or spreading. Panicle axis scabrous. Panicle branches secund; scabrous; pubescent in axils.

Spikelets in pairs. Fertile spikelets pedicelled. Pedicels 0.5–1.3 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 1.4–1.7 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; clasping; 0.7–1 mm long; 0.33–0.5 length of spikelet; membranous; without keels; 3 -veined. Lower glume primary vein scabrous. Lower glume apex acute. Upper glume elliptic; 1–1.7 mm long; 0.9–1 length of spikelet; membranous; without keels; 3 -veined. Upper glume surface glabrous, or hispidulous. Upper glume apex obtuse.

FLORETS Basal sterile florets male, or barren; with palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 5 -veined; glabrous, or hispidulous; acute. Palea of lower sterile floret 0.75 length of lemma. Fertile lemma elliptic; dorsally compressed; 1–1.4 mm long; 0.4–0.6 mm wide; indurate; without keel. Lemma margins involute. Lemma apex acute; scabrous. Palea embraced by lemma; involute; indurate.

FRUIT Caryopsis ellipsoid; 0.9 mm long. Embryo 0.4–0.5 length of caryopsis. Hilum punctiform.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, northern South America, western South America, Brazil, and southern South America.

NOTES Paniceae. Zuloaga 1994.

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