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.

Chondrosum simplex

HABIT Annual; caespitose. Culms geniculately ascending, or decumbent; 3–20(–40) cm long. Leaf-sheaths glabrous on surface. Ligule a fringe of hairs. Leaf-blades flat, or involute; 2–8 cm long; 1.5 mm wide. Leaf-blade surface glabrous, or pilose; hairy adaxially. Leaf-blade margins glabrous, or ciliate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; unilateral; 1–2.5 cm long; bearing 30–80 fertile spikelets on each. Rhachis semiterete. Spikelet packing broadside to rhachis; crowded.

Spikelets pectinate; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 3.5–5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; pilose.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 2–2.5 mm long; 0.5 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins distinct. Lower glume apex acute, or acuminate. Upper glume lanceolate; 3.5–5 mm long; 1.5 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex acute, or acuminate.

FLORETS Fertile lemma oblong; 2.5–3.5 mm long; coriaceous; keeled; 3 -veined. Lemma surface pubescent. Lemma apex lobed; 3 -fid; awned; 3 -awned. Principal lemma awn 2 mm long overall. Lateral lemma awns arising on margin of lemma; 1–1.5 mm long; shorter than principal. Palea 2 -veined. Rhachilla extension pilose; hairy at tip. Apical sterile florets 1 in number, or 2 in number; barren; rudimentary. Apical sterile lemmas awned; 3 -awned. Apical sterile lemma awns 5–6 mm long.

FRUIT Caryopsis with adherent pericarp; obovoid; 1.5–1.75 mm long. Embryo 0.66 length of caryopsis.

DISTRIBUTION North America: northwest USA, southwest USA, south-central USA, and Mexico. South America: western South America and southern South America.

NOTES Cynodonteae. Gould.

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