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.

Gymnopogon ambiguus

HABIT Perennial. Rhizomes short. Culms erect, or geniculately ascending; 20–100 cm long. Leaves distichous. Leaf-sheaths mostly shorter than adjacent culm internode; without keel. Ligule a ciliate membrane; 0.2 mm long. Leaf-blade base broadly rounded. Leaf-blades lanceolate; flat, or conduplicate; (1.5–)2.5–7(–9) cm long; (2–)4–10(–15) mm wide; stiff, or firm. Leaf-blade midrib indistinct.

INFLORESCENCE Inflorescence composed of racemes.

Racemes few, or numerous; (8–)12–37(–47); borne along a central axis; spreading, or deflexed; straight; unilateral; (3–)7–19(–24) cm long. Central inflorescence axis 7–25 cm long. Rhachis angular; scabrous on margins. Spikelet packing broadside to rhachis; distant.

Spikelets appressed; solitary. Fertile spikelets pedicelled. Pedicels oblong.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with diminished florets at the apex. Spikelets lanceolate; laterally compressed; 4.1–6.9 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets; gaping. Lower glume linear; 3.5–5.2 mm long; 0.7–0.9 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume linear; (4.1–)4.6–6.1(–6.9) mm long; 1.1–1.6 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scaberulous. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma elliptic; (2.7–)3.1–3.9(–4.2) mm long; membranous; keeled; 3 -veined. Lemma margins eciliate, or ciliate. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn subapical; flexuous; (3.8–)5–9.6(–11) mm long overall. Palea 1.1 length of lemma. Rhachilla extension 1.5–3 mm long. Apical sterile florets 1 in number; barren; rudimentary. Apical sterile lemmas awned; 1 -awned. Apical sterile lemma awns (0.7–)2.4–5.9(–6.4) mm long.

FLOWER Anthers 3; 0.8–1.2 mm long.

FRUIT Caryopsis with adherent pericarp; 2–3 mm long.

DISTRIBUTION North America: north-central USA, northeast USA, south-central USA, and southeast USA. South America: Caribbean.

NOTES Cynodonteae. Smith.

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