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 diversiglumis

HABIT Annual. Culms decumbent; 25–60 cm long; 0.5–0.7 mm diam.; rooting from lower nodes. Culm-internodes distally glabrous. Culm-nodes bearded. Leaf-sheaths glabrous on surface, or hirsute; with tubercle-based hairs. Ligule an eciliate membrane; 0.7 mm long. Leaf-blades 2–6 cm long; 1.5–2 mm wide. Leaf-blade surface glabrous, or hirsute; with tubercle-based hairs.

INFLORESCENCE Inflorescence a panicle, or composed of racemes.

Panicle open; oblong; secund; 5–12 cm long. Primary panicle branches spreading, or drooping; simple; bearing 2(–4) fertile spikelets on each lower branch. Panicle axis bearing deciduous branches.

Racemes borne along a central axis; spreading, or drooping; paucilateral; bearing few fertile spikelets; bearing 2(–4) fertile spikelets on each. Rhachis deciduous from axis. Spikelet packing distant.

Spikelets solitary. Fertile spikelets pedicelled; heteromorphic.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 3.5–4.2 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume orbicular; 0.2–0.3 mm long; 1 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex obtuse. Upper glume orbicular; 0.2–0.3 mm long; 0.05 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex obtuse; awned only on distal spikelets; 1 -awned. Upper glume awn 1–6 mm long.

FLORETS Fertile lemma lanceolate; 3.5–4.2 mm long; membranous; without keel; 3 -veined. Lemma lateral veins prominent. Lemma apex dentate; 2 -fid; acuminate; awned; 1 -awned. Principal lemma awn from a sinus; flexuous; 7–10 mm long overall. Palea 1 length of lemma; 2 -veined. Palea apex with excurrent keel veins.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 0.4–0.6 mm long; orange.

FRUIT Caryopsis with adherent pericarp; fusiform.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, northern South America, and western South America.

NOTES Eragrostideae. Fl Costa Rica 1994.

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