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 euclaston

HABIT Annual. Culms geniculately ascending; 50–60 cm long; 2–4 -noded. Culm-nodes glabrous. Leaf-sheaths glabrous on surface, or pubescent. Ligule an eciliate membrane; 1 mm long; truncate. Leaf-blades flat, or conduplicate; 3–10 cm long; 2–3 mm wide. Leaf-blade surface pubescent; hairy on both sides.

INFLORESCENCE Inflorescence composed of racemes; subtended by an inflated leaf-sheath; exserted, or embraced at base by subtending leaf.

Racemes 1; single; bilateral; 2–8 cm long; 5–8 mm wide. Rhachis fragile at the nodes; flattened; scabrous on margins. Spikelet packing broadside to rhachis. Rhachis internodes oblong; 1–1.5 mm long; falling with spikelet above.

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

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas; lanceolate; dorsally compressed; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes markedly unequal in width (subulate & lanceolate); coriaceous and subulate; entire; awned. Companion sterile spikelet lemmas 1; 1-awned.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 8–12 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes collateral; similar; exceeding apex of florets; gaping. Lower glume lanceolate; 8–12 mm long; 1 length of upper glume; coriaceous. Lower glume surface scabrous. Lower glume apex setaceously attenuate. Upper glume lanceolate; 8–12 mm long; coriaceous. Upper glume apex setaceously attenuate.

FLORETS Fertile lemma lanceolate; 8–9 mm long; coriaceous; without keel; 5 -veined. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn 8–10 mm long overall. Palea 6–7 mm long.

FLOWER Lodicules 2. Anthers 3; 0.5 mm long. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; ovoid; 2.5–3 mm long; hairy at apex. Hilum linear.

DISTRIBUTION South America: Brazil and southern South America.

NOTES Triticeae. Fl Pat 1995.

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