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 hirsutum

HABIT Perennial; mat forming, or caespitose. Stolons absent, or present. Culms erect; 15–40(–60) cm long; 4–6 -noded. Culm-nodes swollen. Lateral branches lacking. Leaves basal and cauline. Leaf-sheaths glabrous on surface, or pubescent. Leaf-sheath oral hairs ciliate. Ligule a fringe of hairs. Leaf-blades flat, or involute; 1–2 mm wide. Leaf-blade margins tuberculate-ciliate; hairy at base.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1–4; borne along a central axis; unilateral; 2.5–4 cm long; bearing 20–50 fertile spikelets on each. Central inflorescence axis 10–30 cm long. Rhachis flattened; terminating in a barren extension; extension bristle-like; extension 5–10 mm long. 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; 6 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; reaching apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 3 mm long; 0.5 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface asperulous. Lower glume margins ciliate. Lower glume apex acuminate; awned; 1 -awned. Lower glume awn 1–3 mm long; ciliolate. Upper glume lanceolate; 6 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface asperulous; pilose; with tubercle-based hairs. Upper glume margins ciliate. Upper glume apex acuminate; awned; 1 -awned. Upper glume awn 1–3 mm long.

FLORETS Fertile lemma oblong; 6 mm long; coriaceous; keeled; 3 -veined. Lemma surface pubescent. Lemma apex lobed; 3 -fid; awned; 1 -awned. Principal lemma awn 1 mm long overall. Palea 2 -veined. Rhachilla extension glabrous. Apical sterile florets 2 in number; barren; in a clump; cuneate; 1–1.5 mm long. Apical sterile lemmas lobed; 2 -fid; obtuse; awned; 3 -awned. Apical sterile lemma awns 4 mm long.

FLOWER Anthers 2–2.5 mm long; pallid, or yellow.

FRUIT Caryopsis with adherent pericarp; obovoid; 1.5–2 mm long. Embryo 0.7–0.8 length of caryopsis.

DISTRIBUTION North America: northwest USA, north-central USA, southwest USA, south-central USA, southeast USA, and Mexico. South America: Mesoamericana.

NOTES Cynodonteae. Gould.

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