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.

Polypogon interruptus

HABIT Perennial; caespitose. Culms decumbent; 30–80 cm long. Ligule an eciliate membrane; 2–5 mm long. Leaf-blades 4–6 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted, or spiciform; oblong; continuous, or interrupted; 5–15 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels cuneate; 0.5–1 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets cuneate; laterally compressed; 2.5–3 mm long; falling entire; deciduous with the pedicel. Floret callus glabrous.

GLUMES Glumes similar; exceeding apex of florets; firmer than fertile lemma; gaping. Lower glume oblong; 2.5–3 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface scabrous. Lower glume apex emarginate; awned; 1 -awned. Lower glume awn 3–5 mm long. Upper glume oblong; 2.5–3 mm long; 2.5–3 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface scabrous. Upper glume apex obtuse; awned; 1 -awned. Upper glume awn 3–5 mm long.

FLORETS Fertile lemma oblong; 1 mm long; cartilaginous; shiny; without keel; 5 -veined. Lemma apex dentate; 4 -fid; truncate; awned; 1 -awned. Principal lemma awn from a sinus; 1.5–2 mm long overall. Palea 1 length of lemma; hyaline; 2 -veined.

FLOWER Lodicules 2; membranous. Anthers 3.

FRUIT Caryopsis with adherent pericarp; oblong.

DISTRIBUTION Pacific: north-central. North America: western Canada, northwest USA, north-central USA, southwest USA, south-central USA, southeast USA, and Mexico. South America: northern South America, western South America, and southern South America.

NOTES Aveneae. Man US Gr.

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