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 gracile

HABIT Perennial; caespitose. Culms erect, or decumbent; 25–60 cm long. Culm-nodes glabrous, or pubescent. Ligule a fringe of hairs. Leaf-blades 5–10 cm long; 1–2.5 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1–3(–4); single, or borne along a central axis; spreading; arcuate; unilateral; 1.5–5 cm long. Central inflorescence axis 2–5 cm long; tip without extension, or subulate. Rhachis semiterete; scabrous on surface. 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; 5–6 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pilose.

GLUMES Glumes persistent; similar; reaching apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 3–3.5 mm long; 0.6 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein smooth, or scabrous; eciliate, or ciliate. Lower glume lateral veins absent. Lower glume apex setaceously attenuate. Upper glume lanceolate; 5–6 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein smooth to scabrous; eciliate to ciliate. Upper glume lateral veins absent. Upper glume apex setaceously attenuate.

FLORETS Fertile lemma oblong; 4–6 mm long; coriaceous; keeled; 3 -veined. Lemma surface pubescent. Lemma apex lobed; 3 -fid; with outer lobes shorter and with central lobe bidentate; incised 0.3 of lemma length; awned; 3 -awned. Principal lemma awn from a sinus; 1–3 mm long overall. Lateral lemma awns arising on inner edge of lobes; 0.5–2 mm long; shorter than principal. Palea 2 -veined. Palea keels ciliolate. Palea apex with excurrent keel veins. Rhachilla extension pubescent; hairy at tip. Apical sterile florets 1(–2) in number; barren; cuneate; 0.4 mm long. Apical sterile lemmas lobed; 2 -fid; obtuse; awned; 3 -awned. Apical sterile lemma awns 2–3 mm long.

FRUIT Caryopsis with adherent pericarp; 2.5–3 mm long. Embryo 0.75 length of caryopsis.

DISTRIBUTION North America: western Canada, northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, southeast USA, and Mexico.

NOTES Cynodonteae. Gould.

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