Elymus mackenzii

HABIT Perennial; culms solitary. Culms slender; 90–120 cm long. Leaf-sheaths smooth. Ligule an eciliate membrane. Leaf-blades 10–20 cm long; 4–8 mm wide; light green. Leaf-blade surface pilose; densely hairy; hairy abaxially.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; bilateral; 8–20 cm long; 5 mm wide. Spikelet packing broadside to rhachis. Rhachis internodes linear. Rhachis internode tip flat.

Spikelets solitary (or paired at base of raceme). Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1–3 fertile florets; with diminished florets at the apex. Spikelets elliptic to oblong; laterally compressed; 10–20 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes collateral; persistent; similar; shorter than spikelet. Lower glume linear; 9 mm long; 1 length of upper glume; coriaceous; without keels; 5–7 -veined. Lower glume lateral veins prominent. Lower glume apex acute; awned; 1 -awned. Lower glume awn 6–8 mm long. Upper glume linear; 9 mm long; 1 length of adjacent fertile lemma; coriaceous; without keels; 5–7 -veined. Upper glume lateral veins prominent. Upper glume apex acute; awned; 1 -awned. Upper glume awn 6–8 mm long.

FLORETS Fertile lemma lanceolate; 9 mm long; coriaceous; 5 -veined. Lemma surface smooth, or scabrous; rough on veins. Lemma apex acute; awned; 1 -awned. Principal lemma awn 20–30 mm long overall. Palea 7–9 mm long. Apical sterile florets resembling fertile though underdeveloped.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: north-central USA and southeast USA.

NOTES Triticeae. Bush 2010.

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