Elymus interruptus

HABIT Perennial. Culms 60–130 cm long. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane. Leaf-blades 15–30 cm long; 5–12 mm wide. Leaf-blade surface scabrous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; flexuous; bilateral; 8–20 cm long. Rhachis flattened. Spikelet packing broadside to rhachis. Rhachis internodes linear. Rhachis internode tip flat.

Spikelets in pairs. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1–2 fertile florets; with diminished florets at the apex. Spikelets elliptic to oblong; laterally compressed; 10 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes collateral; persistent; similar; shorter than spikelet. Lower glume subulate; 10–30 mm long; 1 length of upper glume; coriaceous; 1 -veined. Lower glume surface puberulous. Upper glume subulate; 10–30 mm long; coriaceous; 1 -veined. Upper glume surface puberulous.

FLORETS Fertile lemma elliptic; 10 mm long; 2 mm wide; chartaceous; 5 -veined. Lemma lateral veins distinct (above). Lemma surface scabrous; glabrous, or pubescent. Lemma apex acute; awned; 1 -awned. Principal lemma awn flexuous; 10–30 mm long overall. Palea 1 length of lemma. Palea keels scabrous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3. Stigmas 2. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: northwest USA, north-central USA, northeast USA, south-central USA, southeast USA, and Mexico.

NOTES Triticeae. Man US Gr 1994.

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