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.

Hordeum depressum

HABIT Annual. Culms erect, or geniculately ascending; 5–45 cm long. Leaf-sheath auricles absent. Ligule an eciliate membrane; 0.1–0.5 mm long. Leaf-blades flat, or conduplicate, or involute; 1–3(–4) mm wide.

INFLORESCENCE Inflorescence composed of racemes; exserted, or embraced at base by subtending leaf.

Racemes 1; single; bilateral; 1.5–6 cm long. Rhachis fragile at the nodes; flattened. Spikelet packing broadside to rhachis. Rhachis internodes oblong; falling with spikelet above.

Spikelets in threes. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster. Pedicels oblong; 0.5–1 mm long.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas; lanceolate; dorsally compressed; 3–5 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes subulate. Companion sterile spikelet lemmas muticous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 5–10 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes collateral; similar. Lower glume subulate; 8.5–15 mm long; 1 length of upper glume. Lower glume margins eciliate. Upper glume subulate; 8.5–15 mm long. Upper glume margins eciliate.

FLORETS Fertile lemma ovate; 5–8(–10) mm long; coriaceous; without keel; 5 -veined. Lemma surface smooth, or scaberulous; rough above. Lemma apex attenuate; awned; 1 -awned. Principal lemma awn 5–10(–20) mm long overall.

FLOWER Anthers 3; 0.6–1 mm long. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION North America: western Canada, northwest USA, southwest USA, and Mexico.

NOTES Triticeae. Intermountain Fl. 20044.

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