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.

Orcuttia viscida

HABIT Annual. Culms erect, or geniculately ascending; 3–10 cm long. Lateral branches lacking. Leaves without demarcation between sheath and blade. Leaf-sheaths viscid. Ligule absent. Leaf-blades 2–4 mm wide; viscid; aromatic. Leaf-blade surface pilose.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; bilateral; 3–5 cm long; bearing few fertile spikelets; bearing 6–20 fertile spikelets on each. Rhachis angular. Spikelet packing broadside to rhachis; crowded.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 5–15 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; 5–6 mm long; 1 length of upper glume; chartaceous; without keels; 5–9 -veined. Lower glume apex lobed; 3 -fid; setaceously attenuate. Upper glume lanceolate; 5–6 mm long; chartaceous; without keels; 5–9 -veined. Upper glume apex lobed; 3 -fid; setaceously attenuate.

FLORETS Fertile lemma oblong; 6–7 mm long; chartaceous; keeled; 15 -veined. Lemma lateral veins prominent. Lemma apex lobed; 5 -fid; with outer lobes shorter; incised 0.5 of lemma length; awned; 5 -awned. Principal lemma awn 1–2 mm long overall. Palea 0.75 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; 2.3–2.5 mm long; light brown. Embryo 1 length of caryopsis.

DISTRIBUTION North America: southwest USA.

NOTES Orcuttieae. Reeder 1998.

ADDITIONAL CHARACTERS Glume teeth unequal.

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