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.

Psathyrostachys juncea

HABIT Perennial; caespitose. Butt sheaths grey, or light brown; glabrous. Culms 20–110 cm long; 2–4 -noded. Culm-internodes distally glabrous. Leaf-sheath oral hairs lacking. Leaf-sheath auricles falcate. Ligule an eciliate membrane; 0.2–0.3 mm long. Leaf-blades flat, or involute; 6–30 cm long; 7–18 mm wide; glaucous, or grey-green. Leaf-blade surface scabrous; rough abaxially, or on both sides; glabrous. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence composed of racemes. Peduncle pubescent above.

Racemes 1; single; bilateral; 4.5–12.5 cm long; 5–12 mm wide. Rhachis fragile at the nodes; pubescent on surface; ciliate on margins. Spikelet packing broadside to rhachis. Rhachis internodes cuneate; 3.7–6 mm long; falling with spikelet above.

Spikelets in threes. Fertile spikelets sessile; 3 in the cluster; subequal.

FERTILE SPIKELETS Spikelets comprising 1–3 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; dorsally compressed; 6.1–9.4 mm long; 1.4–1.8 mm wide; falling entire; deciduous with accessory branch structures.

GLUMES Glumes collateral; similar; exceeding apex of florets; gaping. Lower glume subulate; 4.5–9.4 mm long; 1 length of upper glume. Lower glume surface scabrous; glabrous to pubescent; hairy generally, or below. Lower glume hairs 0.2–0.5 mm long. Upper glume subulate; 4.5–9.4 mm long. Upper glume surface scabrous; glabrous to puberulous; hairy generally, or below. Upper glume hairs 0.2–0.5 mm long.

FLORETS Fertile lemma lanceolate; 6.1–9.4 mm long; coriaceous; without keel; 7 -veined. Lemma surface glabrous to pubescent; hairy below. Lemma hairs 0.1–0.5 mm long. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn 2–3 mm long overall. Palea coriaceous. Rhachilla extension 3.2–6.2 mm long.

FLOWER Anthers 3.8–5.1 mm long. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; 4.3–5 mm long. Hilum linear.

DISTRIBUTION Europe: eastern. Asia-temperate: Siberia, Soviet Middle Asia, western Asia, China, and Mongolia. South America: western South America.

NOTES Triticeae. Baden 1992.

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