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 tenuiflora

HABIT Perennial. Rhizomes elongated; scaly. Culms erect, or geniculately ascending; 60–100 cm long. Culm-internodes distally pubescent. Culm-nodes pubescent. Lateral branches lacking, or sparse. Leaf-sheaths loose; pubescent. Ligule an eciliate membrane; 0.5 mm long. Leaf-blades spreading; 8–15 cm long; 5–8(–13) mm wide. Leaf-blade venation with 5–13 secondary veins. Leaf-blade surface scaberulous; rough on both sides. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence a panicle. Peduncle glabrous.

Panicle contracted; linear; nodding; 15–30 cm long; 0.5 cm wide. Primary panicle branches appressed; 4–8 cm long. Panicle axis scabrous. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 2.5–3.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 1.5–2.5 mm long; 0.9 length of upper glume; membranous; without keels; 1–5 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent, or distinct. Lower glume surface asperulous; rough above. Lower glume apex acuminate, or setaceously attenuate. Upper glume lanceolate; 1.7–2.6 mm long; 0.66–0.75 length of adjacent fertile lemma; membranous; without keels; 1–5 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent, or distinct. Upper glume surface asperulous; rough above. Upper glume apex acuminate, or setaceously attenuate.

FLORETS Fertile lemma lanceolate; 2.5–3.5 mm long; membranous; without keel; 3 -veined. Lemma surface pubescent; hairy below. Lemma hairs white. Lemma apex acute; awned; 1 -awned. Principal lemma awn 2–11 mm long overall. Palea 2 -veined. Palea surface pubescent; hairy below.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 1–1.3 mm long.

FRUIT Caryopsis with adherent pericarp; fusiform; 1.75–2.2 mm long.

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

NOTES Eragrostideae. Gr Indiana 1994.

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