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.

Orcuttia californica

HABIT Annual; caespitose. Culms prostrate; 5–15(–20) cm long. Leaves without demarcation between sheath and blade. Leaf-sheaths viscid. Ligule absent. Leaf-blades 1–2 cm long; 2–3 mm wide; viscid; aromatic. Leaf-blade surface pilose; sparsely hairy.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; bilateral; 3–6 cm long. Rhachis angular; pubescent on surface. Spikelet packing broadside to rhachis; distant (below).

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 5–15(–25) fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 5–12 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 2–3(–4) mm long; 1 length of upper glume; chartaceous; without keels; 5–9 -veined. Lower glume apex dentate; 2–5 -fid. Upper glume lanceolate; 2–3(–4) mm long; 0.5–0.75 length of adjacent fertile lemma; chartaceous; without keels; 5–9 -veined. Upper glume apex dentate; 2–5 -fid.

FLORETS Fertile lemma oblong; 5 mm long; chartaceous; keeled; 15 -veined. Lemma lateral veins prominent. Lemma apex lobed; 5 -fid; with simple equal lobes; incised 0.33 of lemma length; mucronate; 5 -awned (mucros). Palea 1 length of lemma; 2 -veined. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules absent. Anthers 3; 2 mm long. Stigmas 2; sparsely hairy.

FRUIT Caryopsis with adherent pericarp; ellipsoid; laterally compressed; 1.5–1.8 mm long; dark brown. Embryo 0.75 length of caryopsis.

DISTRIBUTION North America: southwest USA and Mexico.

NOTES Orcuttieae. Reeder.

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