Danthonia compressa

HABIT Perennial; caespitose. Rhizomes absent, or short. Culms geniculately ascending, or decumbent; 40–80 cm long; disarticulating at the nodes. Leaf-sheaths glabrous on surface. Leaf-sheath oral hairs bearded. Ligule a fringe of hairs. Collar glabrous, or pubescent. Leaf-blades filiform; involute; 10–25 cm long; 2–3 mm wide. Leaf-blade surface scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open, or contracted; lanceolate; 5–8 cm long. Primary panicle branches bearing 2–3 fertile spikelets on each lower branch.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets with diminished florets at the apex. Spikelets elliptic; laterally compressed; 10–14 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus brief; pubescent.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 10–14 mm long; 1 length of upper glume; membranous; without keels; 3 -veined. Lower glume apex acuminate. Upper glume lanceolate; 10–14 mm long; 3 length of adjacent fertile lemma; membranous; without keels; 5 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma elliptic; 3.5–5 mm long; chartaceous; without keel; 5 -veined. Lemma margins ciliate. Lemma apex lobed; 2 -fid; incised 0.33 of lemma length; awned; 3 -awned. Principal lemma awn from a sinus; geniculate; 6–7 mm long overall; with twisted column. Lateral lemma awns arising on apex of lobes; 2–3 mm long; shorter than principal. Palea 2 -veined. Palea keels winged; narrowly winged; ciliolate. Apical sterile florets resembling fertile though underdeveloped.

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

FRUIT Caryopsis with adherent pericarp. Hilum linear.

CLEISTOGENES AND VIVIPARY Cleistogenes present; in lower sheaths.

DISTRIBUTION North America: eastern Canada, northeast USA, and southeast USA.

NOTES Arundineae. Man US Gr 1993.

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