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.

Muhlenbergia frondosa

HABIT Perennial. Rhizomes elongated; scaly. Culms decumbent, or prostrate; slender; 30–90 cm long. Culm-internodes smooth; distally glabrous. Lateral branches ample; arising from upper culm. Leaf-sheaths mostly shorter than adjacent culm internode; without keel; glabrous on surface. Ligule an eciliate membrane, or a ciliolate membrane; 0.8–1(–1.4) mm long; erose. Leaf-blades 4–12 cm long; 1–7 mm wide. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence a panicle; terminal and axillary. Peduncle 1–2 cm long.

Panicle contracted; linear, or lanceolate; interrupted; dense; 3–10 cm long; 0.1–0.6(–0.9) cm wide. Primary panicle branches appressed, or ascending; bearing spikelets almost to the base.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels linear.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 2.9–4 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet, or reaching apex of florets, or exceeding apex of florets; similar to fertile lemma in texture. Lower glume lanceolate; 2–4 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute to setaceously attenuate. Upper glume lanceolate; 2–4 mm long; 0.7–1.1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute to setaceously attenuate.

FLORETS Fertile lemma lanceolate; 2.9–3.6 mm long; membranous; keeled; 3 -veined. Lemma apex acute; mucronate, or awned; 1 -awned. Principal lemma awn 1–2 mm long overall. Palea 1 length of lemma; 2 -veined.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 0.3–0.6 mm long; yellow.

FRUIT Caryopsis with adherent pericarp; fusiform.

DISTRIBUTION North America: eastern Canada, north-central USA, northeast USA, south-central USA, and southeast USA.

NOTES Eragrostideae. Gould.

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