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Aquatic and Wetland Vascular Plants of the Northern Great Plains

63. Poaceae, the Grass Family

5. Bromus L. -- Brome grass

1. Bromus ciliatus L. -- Fringed brome


Nonrhizomatous perennial 5-12 dm tall; culms few together or single, often pubescent at the nodes. Leaf blades flat, 3.5-10(12) mm wide, glabrous or pilose mainly on the upper surface; sheaths glabrous to pilose; ligule membranous, very short to 1.5 mm long, erose. Inflorescence a loose, open panicle 7-20(33) cm long, the branches usually drooping; spikelets rather large, 4- to 10-flowered, 14-25(35) mm long, 4-10 mm wide; glumes glabrous to scabrous on the nerves, the first glume 4-9.5 mm long, 1-nerved or some rarely 3-nerved, acute, the second glume 6-11(14) mm long, 3-nerved, acute or with a short-awned tip; lemmas mostly 8-15 mm long, reduced upward, 5- to 7-nerved, usually prominently villous along the margins mainly in the lower 1/2 to 3/4, glabrous on the back or short-pubescent toward the base, awned from between the teeth of a minutely bifid apex, the awn 1-6 mm long; palea about equaling the body of the lemma; anthers highly variable in size, 0.7-2(4.6) mm long. Grain elongate, about equaling the palea, retained between the lemma and palea. Jul--Aug(Sep). Wet to moist ground of fresh springs, fens, stream banks and thickets, also in moist woods; occasional; (Newf. to WA, s to NJ, TN, IA, TX and CA).

Of the several native species of brome in the region, B. ciliatus is the only one found in wet ground with regularity. Although better known from moist woods in other parts of its range, in our area it demonstrates a clear preference for open, wet to moist places where surface water is fresh.

Smooth brome, Bromus inermis Leyss., is naturalized throughout our range. Because of its abundance and ubiquity, it is common to find smooth brome in moist meadows and other habitats associated with prairie wetlands. The rhizomatous habit and awnless or very short-awned, glabrous to scabrous lemmas make smooth brome distinctive among our bromes.

The weedy nature of the introduced annual bromes accounts for their frequent occurrence in previously flooded areas, e.g. dried shores, floodplains, etc. The most commonly encountered of these are Japanese brome, Bromus japonicus Thunb. ex Murr. and downy brome, B. tectorum L. Both are much better known as upland weeds.

GIF- Species Photo/Drawing

Bromus ciliatus (from Hitchcock 1950).
GIF- Distribution Map

Map key


Previous Section -- Beckmannia syzigachne (Steud.) Fern. -- Western sloughgrass
Return to Family -- Poaceae - The Grass Family
Next Section -- Calamagrostis canadensis (Michx.) Beauv. -- Bluejoint reedgrass

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