Danthonia decumbens

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 10–45(–70) cm long; 1–3 -noded. Leaves mostly basal. Leaf-sheath oral hairs bearded. Ligule a fringe of hairs. Leaf-blades flat, or involute; 5–25 cm long; 2–4 mm wide. Leaf-blade apex obtuse, or abruptly acute.

INFLORESCENCE Inflorescence a panicle; comprising (3–)4–9(–11) fertile spikelets.

Panicle contracted; linear, or oblong; 2–7 cm long; bearing few spikelets. Primary panicle branches bearing 1–3 fertile spikelets on each lower branch.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 4–6 fertile florets; with diminished florets at the apex. Spikelets elliptic, or oblong; laterally compressed; (6.5–)8–11(–13) mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.5 mm long. Floret callus pubescent.

GLUMES Glumes persistent; similar; reaching apex of florets; thinner than fertile lemma. Lower glume lanceolate, or ovate; (3–)4–9(–11) mm long; 1 length of upper glume; membranous; 1-keeled; keeled above; 3–5 -veined. Lower glume apex obtuse, or acute. Upper glume lanceolate, or ovate; 1.2–1.7 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled; keeled above; 3–5 -veined. Upper glume apex obtuse, or acute.

FLORETS Fertile lemma elliptic; 5–7 mm long; coriaceous; without keel; 7–9 -veined. Lemma margins pubescent; hairy below. Lemma apex dentate; 2 -fid; mucronate. Principal lemma awn from a sinus. Palea 1 length of lemma; 2 -veined. Palea keels ciliolate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; cuneate; fleshy; glabrous. Anthers 3; 0.2–0.5 mm long; retained within floret.

FRUIT Caryopsis with adherent pericarp; ellipsoid. Embryo 0.33 length of caryopsis. Hilum linear; 0.25 length of caryopsis.

CLEISTOGENES AND VIVIPARY Cleistogenes present; in lower sheaths.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Africa: north, Macaronesia, and middle Atlantic ocean. Asia-temperate: Caucasus and western Asia. Australasia: Australia and New Zealand. North America: eastern Canada, northwest USA, northeast USA, and southwest USA. South America: Mesoamericana.

NOTES Arundineae. TAC.

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