Elymus arizonicus

HABIT Perennial; caespitose. Culms erect; 60–100 cm long. Leaf-sheath auricles falcate. Ligule an eciliate membrane; 2–4 mm long. Leaf-blades flat, or conduplicate; 2.5–6 mm wide; glaucous. Leaf-blade surface glabrous, or puberulous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; flexuous; bilateral; 10–25 cm long. Rhachis flattened; scabrous on margins. Spikelet packing broadside to rhachis; lax. Rhachis internodes linear; 9–15 mm long.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 4–6 fertile florets; with diminished florets at the apex. Spikelets elliptic to oblong; laterally compressed; 15 mm long; breaking up at maturity; disarticulating above glumes but not between florets.

GLUMES Glumes collateral; persistent; similar; shorter than spikelet. Lower glume lanceolate; 8–10 mm long; 1 length of upper glume; coriaceous; without keels; 3–5 -veined. Lower glume apex acute, or acuminate; muticous, or awned; 1 -awned. Lower glume awn 0–8 mm long. Upper glume lanceolate; 8–10 mm long; 1 length of adjacent fertile lemma; coriaceous; without keels; 3–5 -veined. Upper glume apex acute, or acuminate; muticous, or awned; 1 -awned. Upper glume awn 0–8 mm long.

FLORETS Fertile lemma lanceolate; 10 mm long; coriaceous; 5–7 -veined. Lemma surface smooth, or scaberulous. Lemma apex acute; awned; 1 -awned. Principal lemma awn curved; 15–30 mm long overall; limb scabrous. 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: southwest USA, south-central USA, and Mexico. South America: Mesoamericana.

NOTES Triticeae. Gr Tex 1993.

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