Leymus arenarius

HABIT Perennial; caespitose. Rhizomes elongated. Culms erect, or geniculately ascending; 60–200 cm long. Leaves cauline. Leaf-sheaths glabrous on surface. Leaf-sheath oral hairs lacking. Leaf-sheath auricles falcate. Ligule an eciliate membrane; 0.3–1 mm long; truncate. Leaf-blades flat, or involute; 20–60 cm long; 8–22 mm wide; stiff; glaucous. Leaf-blade surface ribbed; scaberulous; rough adaxially. Leaf-blade apex acuminate; hardened.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; erect; bilateral; 15–35 cm long. Rhachis flattened; scabrous on margins. Spikelet packing broadside to rhachis; regular; 2 -rowed.

Spikelets appressed; in pairs. Fertile spikelets sessile; 2 in the cluster.

FERTILE SPIKELETS Spikelets comprising 3–6 fertile florets; with diminished florets at the apex. Spikelets oblong, or cuneate; laterally compressed; 20–32 mm long; breaking up at maturity; disarticulating below each fertile floret. Spikelet callus glabrous; base truncate. Rhachilla internodes definite; obscured by lemmas; pubescent.

GLUMES Glumes persistent; similar; subequal in width; reaching apex of florets, or shorter than spikelet. Lower glume lanceolate; 18–30 mm long; 1 length of upper glume; coriaceous; 1-keeled; 3–5 -veined. Lower glume surface pubescent. Lower glume apex attenuate. Upper glume lanceolate; 18–30 mm long; 1.2 length of adjacent fertile lemma; coriaceous; 1-keeled; 3–5 -veined. Upper glume surface pubescent. Upper glume apex attenuate.

FLORETS Fertile lemma lanceolate; 15–25 mm long; coriaceous; keeled; keeled above; 7 -veined. Lemma surface pubescent. Lemma apex acute. Palea lanceolate; 1 length of lemma; 2 -veined. Palea keels ciliolate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; elliptic; membranous. Anthers 3; 7–8 mm long. Stigmas 2; protandrous; laterally exserted. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; fusiform; isodiametric; estipitate; without sulcus; 10 mm long; smooth; apex unappendaged. Embryo 0.2 length of caryopsis. Hilum linear; 0.9 length of caryopsis. Endosperm farinose.

DISTRIBUTION Europe: northern, central, southwestern, and eastern. Australasia: Australia and New Zealand. North America: Subarctic, western Canada, eastern Canada, and northwest USA. South America: southern South America. Antarctic: Subantarctic islands.

NOTES Triticeae. CEH.

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