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.

Agrostis laxissima

HABIT Perennial. Culms decumbent; weak; 50–60 cm long. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 3–4 mm long. Leaf-blades 8–15 cm long; 1–3 mm wide. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; 7–8 cm long; bearing few spikelets. Primary panicle branches ascending, or spreading. Panicle branches flexuous; scaberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 2 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 2 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 2 mm long; 1.3 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 1.5 mm long; hyaline; without keel; 5 -veined. Lemma lateral veins excurrent. Lemma apex truncate; awned; 1 -awned. Principal lemma awn dorsal; arising 0.33 way up back of lemma; curved; 3 mm long overall. Palea absent or minute.

FLOWER Lodicules 2; membranous. Anthers 3; 0.5 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Aveneae. Swallen 1995.

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