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.

Orinus tibeticus

HABIT Perennial. Rhizomes elongated; scaly. Culms erect; 15–35 cm long. Culm-internodes distally pilose. Leaf-sheaths pilose; outer margin hairy. Leaf-sheath oral hairs ciliate. Ligule an eciliate membrane; 1 mm long; lacerate. Leaf-blades linear, or lanceolate; 2–8 cm long; 2–4 mm wide. Leaf-blade surface ribbed; hirsute; hairy on both sides. Leaf-blade apex attenuate; hardened.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 4–8; borne along a central axis; unilateral; 3–5 cm long. Central inflorescence axis (3.5–)5–9 cm long. Rhachis angular. Spikelet packing broadside to rhachis.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 5–8 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 8–11 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate; 4.5–5.5 mm long; 0.9 length of upper glume; membranous; much thinner on margins; purple; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface glabrous, or pilose. Lower glume apex acute. Upper glume lanceolate; 5–6 mm long; 1 length of adjacent fertile lemma; membranous; with hyaline margins; purple; without keels; 3 -veined. Upper glume surface glabrous, or pilose. Upper glume apex acute.

FLORETS Fertile lemma elliptic; 5–6 mm long; chartaceous; keeled; lightly keeled; 3 -veined. Lemma surface pilose; hairy all along; hairy on back. Lemma apex acute. Palea 2 -veined. Palea keels ciliate. Palea surface pubescent. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 3 mm long.

FRUIT Caryopsis with adherent pericarp; oblong.

DISTRIBUTION Asia-temperate: China.

NOTES Eragrostideae. Fl China 2005.

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