GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Elymus macgregorii

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 40–120 cm long. Leaf-sheaths mostly shorter than adjacent culm internode; glabrous on surface, or pubescent. Leaf-sheath auricles falcate; 2–3 mm long. Ligule an eciliate membrane; 0.4–0.9 mm long; purple; truncate. Leaf-blades drooping; 7–15 mm wide; dark green, or glaucous; pruinose. Leaf-blade surface glabrous, or pubescent; hairy adaxially.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; erect; oblong; bilateral; 4–12 cm long; 25–40 mm wide. Rhachis flattened; 0.3 mm wide. Spikelet packing broadside to rhachis; lax; 4–5 spikelets per cm. Rhachis internodes clavate; 4–7 mm long. Rhachis internode tip clavate.

Spikelets ascending; in pairs. Fertile spikelets sessile; 2(–3) in the cluster.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with diminished florets at the apex. Spikelets elliptic to oblong; dorsally compressed; 10–15 mm long; breaking up at maturity; disarticulating between fertile florets but the lowest falling with glumes attached.

GLUMES Glumes collateral; deciduous; similar; shorter than spikelet. Lower glume lanceolate; gibbous; 8–16 mm long; 1 length of upper glume; coriaceous; without keels; (2–)4–5(–8) -veined. Lower glume surface smooth, or scabrous. Lower glume apex acuminate; awned; 1 -awned. Lower glume awn 10–25 mm long. Upper glume lanceolate; gibbous; 8–16 mm long; 1.2–1.5 length of adjacent fertile lemma; coriaceous; without keels; (2–)4–5(–8) -veined. Upper glume surface smooth, or scabrous. Upper glume apex acuminate; awned; 1 -awned. Upper glume awn 10–25 mm long.

FLORETS Fertile lemma lanceolate to oblong; 6–12 mm long; coriaceous; 5–7 -veined. Lemma surface smooth, or scaberulous; glabrous, or pilose. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn (15–)20–30 mm long overall. Palea 6–10 mm long; 0.9–1 length of lemma. Palea apex obtuse. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 2–4 mm long.

DISTRIBUTION North America: eastern Canada, north-central USA, northeast USA, south-central USA, and southeast USA.

NOTES Triticeae. Campbell 2007.


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