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.

Bromus bonariensis

HABIT Perennial; caespitose. Basal innovations intravaginal. Culms 40–70 cm long; 4–5 -noded. Culm-nodes glabrous. Leaf-sheaths pubescent. Ligule an eciliate membrane; 1–1.5 mm long; obtuse. Leaf-blades flat, or conduplicate; 6–20 cm long; 1–2.5 mm wide. Leaf-blade surface scabrous; glabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 12–20 cm long. Primary panicle branches spreading; 2–4 -nate; 2–8 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 6–9 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; compressed strongly; 20–40 mm long; 6–8 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 3 mm long; pubescent. Floret callus glabrous.

GLUMES Glumes persistent; shorter than spikelet. Lower glume lanceolate; 10–11 mm long; 0.75 length of upper glume; membranous; 1-keeled; 5 -veined. Lower glume lateral veins absent. Lower glume surface scabrous. Lower glume apex acuminate. Upper glume lanceolate; 14–15 mm long; 0.9 length of adjacent fertile lemma; membranous; 1-keeled; 7–9 -veined. Upper glume surface scabrous. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 16–18 mm long; chartaceous; keeled; 9 -veined. Lemma midvein scabrous. Lemma surface scabrous. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; 3–5 mm long overall. Palea 13–14 mm long. Palea keels ciliolate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; 1 mm long; membranous. Anthers 3; 3–7 mm long. Ovary with a fleshy appendage above style insertion; pubescent on apex.

FRUIT Caryopsis with adherent pericarp; linear; 7–9 mm long; hairy at apex; apex fleshy. Hilum linear.

DISTRIBUTION South America: southern South America.

NOTES Bromeae. Parodi 1995.

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