GrassBase - The Online World Grass Flora

Descriptions

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

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

Hordeum stenostachys

HABIT Perennial; caespitose. Butt sheaths pubescent; persistent and investing base of culm; with fibrous dead sheaths. Culms erect; 30–150 cm long; 4–7 -noded. Culm-nodes glabrous. Leaf-sheath auricles absent. Ligule an eciliate membrane; 0.5–3 mm long. Leaf-blades 6–20 cm long; 2–7 mm wide. Leaf-blade surface smooth, or scaberulous, or scabrous; glabrous, or pilose; hairy adaxially.

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

Racemes 1; single; linear; bilateral; 5–12 cm long; 3–5 mm wide. Rhachis fragile at the nodes; narrowly winged; flattened; scabrous on margins; ciliate on margins. Spikelet packing broadside to rhachis. Rhachis internodes oblong; 1.3–2.2 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; 1.7–3.2 mm long.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas; lanceolate; dorsally compressed; 5–12 mm long; shorter than fertile; deciduous with the fertile. Companion sterile spikelet glumes subulate. Companion sterile spikelet lemmas 1.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension, or with a barren rhachilla extension. Spikelets lanceolate; dorsally compressed; 4–10 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes collateral; similar. Lower glume linear; 4–10 mm long; 1 length of upper glume. Lower glume surface scabrous. Upper glume linear; 4–10 mm long. Upper glume surface scabrous.

FLORETS Fertile lemma lanceolate; 5–9 mm long; coriaceous; without keel; 5 -veined. Lemma lateral veins obscure. Lemma surface puberulous, or pubescent; hairy all along. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn 2–8 mm long overall; limb scabrous. Rhachilla extension 0–5.5 mm long.

FLOWER Anthers 3; 2.2–4.4 mm long. Ovary pubescent on apex.

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

DISTRIBUTION Africa: south. South America: Brazil and southern South America.

NOTES Triticeae. Bothmer 1993.

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