GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Danthonia rhizomata

HABIT Perennial. Rhizomes elongated. Culms erect; 35–45 cm long. Leaf-sheaths pilose; with simple hairs, or tubercle-based hairs. Leaf-sheath oral hairs ciliate. Ligule a fringe of hairs; 1 mm long. Leaf-blades flat, or convolute; 7–12 cm long; 1–3 mm wide. Leaf-blade surface pilose; with tubercle-based hairs.

INFLORESCENCE Inflorescence a panicle; comprising 1–4 fertile spikelets.

Panicle open; ovate; 2.5–3 cm long; bearing few spikelets.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels puberulous.

FERTILE SPIKELETS Spikelets comprising 4–7 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 15–25 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; pilose. Floret callus hairs 3–4 mm long.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 15–25 mm long; 1 length of upper glume; membranous; without keels; 3 -veined. Lower glume apex acuminate. Upper glume lanceolate; 15–25 mm long; 1.2–2 length of adjacent fertile lemma; membranous; without keels; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 12 mm long; chartaceous; shiny; without keel; 9 -veined. Lemma surface glabrous; with marginal hair tufts; bearing 4 hair tufts in all. Lemma hairs 1.5–2 mm long. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 3 -awned. Principal lemma awn from a sinus; geniculate; simple at base; 14–16 mm long overall; with twisted column. Lateral lemma awns arising on apex of lobes; 4–5 mm long. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; cuneate; fleshy; glabrous; truncate. Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Brazil and southern South America.

NOTES Arundineae. Swallen 1993.

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