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.

Glyceria fluitans

HABIT Perennial. Culms erect, or decumbent; 50–100 cm long. Leaf-sheaths tubular for much of their length; with 1 of their length closed; keeled; smooth; glabrous on surface. Ligule an eciliate membrane; 5–15 mm long; acute. Leaf-blades flat, or conduplicate; 5–25 cm long; 3–10 mm wide. Leaf-blade surface smooth. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted (spreading at anthesis); linear; equilateral, or nodding; 10–50 cm long. Primary panicle branches spreading; 1–2 -nate; simple; bearing 1–4 fertile spikelets on each lower branch. Panicle branches smooth.

Spikelets appressed; solitary. Fertile spikelets pedicelled. Pedicels 1–4 mm long.

FERTILE SPIKELETS Spikelets comprising 8–16 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 18–35 mm long; 2–3.5 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume oblong; 2–3 mm long; 0.66 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex obtuse. Upper glume oblong; 3–5 mm long; 0.5–0.66 length of adjacent fertile lemma; membranous; without keels; 1(–3) -veined. Upper glume apex obtuse.

FLORETS Fertile lemma oblong; 6–7.5 mm long; membranous; much thinner above; without keel; 7 -veined. Lemma surface scaberulous. Lemma apex acute. Palea 1–1.1 length of lemma; 2 -veined. Palea keels winged; narrowly winged. Palea apex dentate; 2 -fid. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; united; oblong; fleshy; truncate. Anthers 3; 2–3 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 2.5–3 mm long. Embryo 0.2 length of caryopsis. Hilum linear; 1 length of caryopsis.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Africa: north. Asia-temperate: Siberia, Caucasus, and western Asia. Australasia: Australia and New Zealand. Pacific: north-central. North America: western Canada, eastern Canada, north-central USA, northeast USA, and Mexico. South America: western South America.

NOTES Meliceae. CEH.

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