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 distichon

HABIT Annual; caespitose. Culms erect; 60–120 cm long; 3–5 -noded. Leaf-sheath oral hairs lacking. Leaf-sheath auricles falcate. Ligule an eciliate membrane; 1–2 mm long; truncate. Leaf-blades 10–45 cm long; 6–12 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; bilateral; 7–12 cm long. Rhachis tough; flattened; ciliate on margins. Spikelet packing broadside to rhachis; regular; 2 -rowed. Rhachis internodes cuneate.

Spikelets in threes. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 2 in the cluster.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; dorsally compressed; 10 mm long; as long as fertile; persistent. Companion sterile spikelet glumes subulate; 4–5 mm long; ciliate on margins. Companion sterile spikelet lemmas 1; exserted from glumes; 10 mm long; muticous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 9–12 mm long; persistent on plant.

GLUMES Glumes collateral; similar; shorter than spikelet; gaping. Lower glume linear; 4–5 mm long; 1 length of upper glume. Lower glume apex acuminate; awned; 1 -awned. Lower glume awn 4–10 mm long. Upper glume linear; 4–5 mm long; 0.3–0.5 length of adjacent fertile lemma. Upper glume apex acuminate; awned; 1 -awned. Upper glume awn 4–10 mm long.

FLORETS Fertile lemma elliptic; 9–12 mm long; coriaceous; without keel; 5 -veined. Lemma surface scaberulous; rough above. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn 12–15 mm long overall; limb scabrous.

FLOWER Anthers 3. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; sulcate on hilar side; hairy at apex. Hilum linear.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Africa: north and northeast tropical. Asia-temperate: Siberia, Soviet far east, Soviet Middle Asia, Caucasus, western Asia, China, Mongolia, and eastern Asia. Asia-tropical: India. Australasia: Australia and New Zealand. North America: Subarctic. South America: western South America and southern South America.

NOTES Triticeae. Fl Iran.

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