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 longiglumis

HABIT Perennial; caespitose; clumped loosely. Rhizomes elongated; scaly. Culms erect; 20–50 cm long; 1.5–2.5 mm diam.; 6–8 -noded. Culm-internodes distally pilose. Leaf-sheaths longer than adjacent culm internode; hirsute. Ligule an eciliate membrane; 1 mm long; lacerate. Leaf-blades 7–12 cm long; 2.5–4 mm wide. Leaf-blade surface hirsute; hairy on both sides.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 4–6; borne along a central axis; unilateral; 1–9 cm long. Central inflorescence axis 8–23 cm long. Spikelet packing broadside to rhachis.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–4 fertile florets; with diminished florets at the apex. Spikelets lanceolate; laterally compressed; 7–9 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1 mm long; glabrous.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume linear; 6–7 mm long; 0.9 length of upper glume; membranous; much thinner on margins; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 7–8.5 mm long; 1 length of adjacent fertile lemma; membranous; with hyaline margins; without keels; 3 -veined. Upper glume primary vein scaberulous. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 6–7 mm long; chartaceous; keeled; lightly keeled; 3 -veined. Lemma surface villous; hairy all along. Lemma apex dentate; 3 -fid; acute. Palea 5–6 mm long; 2 -veined. Palea keels ciliate. Palea apex dentate; 2 -fid. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 3–3.5 mm long; yellow.

FRUIT Caryopsis with adherent pericarp; oblong; 2.5–3 mm long; light brown.

DISTRIBUTION Asia-temperate: China.

NOTES Eragrostideae. Cai & Su 2011.

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