Bromus kalmii (Kalm's Brome)
|Also known as:||Prairie Brome, Arctic Brome|
|Habitat:||sun; moist to dry sandy or rocky soil; prairies, savanna, wet meadows, calcareous fens, open woods, jack pine forest|
|Fruiting season:||July - September|
|Plant height:||20 to 40 inches|
|Wetland Indicator Status:||GP: FACU MW: FAC NCNE: FAC|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
Pick an image for a larger view. See the glossary for icon descriptions.
Flowering head is an open panicle 4 to 6 inches long, nodding to one side, the branches arching, drooping at the tips with 1 to 3 spikelets (flower clusters) per branch. Spikelets are stalked, oblong-elliptic in outline, slightly flattened, 15 to 25+ mm (to 1+ inch) long, with 6 to 13 florets. One or more sterile florets may be at the tip.
At the base of a spikelet is a pair of bracts (glumes), both hairy, the lower glume 5 to 7 mm long and 3-veined, the upper glume 7 to 9 mm long and 5-veined. Surrounding a floret is a pair of bracts (lemma and palea). Lemmas are lance-oblong, 8 to 10 mm long, 7-veined, moderately to densely covered in long silky hairs giving a gray-green cast, notched at the tip forming 2 teeth, with a straight awn 2 to 3 mm long arising between the teeth. The palea is somewhat shorter than the lemma, 2-veined, hairy on the surface with longer hairs on the veins. Sterile florets are like the fertile but underdeveloped.
Leaves and stems:
Sheath edges are fused for most of their length (a closed sheath), the lower sheaths densely covered in long, downward pointing (retrorse) hairs, the upper sheaths often hairless except for a few long hairs at the tip. The ligule (membrane where the leaf joins the sheath) is membranous, less than 1 mm long, jagged along the top edge and lacks a fringe of hairs. Nodes are mostly hairy. Stems are single or a few from the base in a loose clump, usually erect, hairless or hairy just near the nodes.
Florets mature to light brown, each dropping off individually leaving the glumes persisting on the stalk. Grains are somewhat flattened, elliptic, 6 to 8 mm long, and have a bundle of white hairs at the tip.
Bromes are cool season grasses (optimal growth below 75°), usually clump-forming, have closed sheaths, panicles that are often drooping or nodding to one side, multi-flowered spikelets, unequal glumes, and lemmas that are typically awned, hairy and usually notched at the tip forming 2 teeth with the awn arising between the teeth. The longer leaves also frequently twist from near the base so the underside and upperside are flipped. Most Bromes found in Minnesota have sheaths and nodes that are hairy to various degrees and are mostly distinguished by the number of veins on the glumes, length of the lemma awns, and sometimes leaf characteristics.
Kalm's Brome is distinguished by a 3-veined lower glume, 5-veined upper glume, and lemmas that are silky-hairy all across the surface with awns mostly less than 3 mm long. The hairiness of sheaths and leaves is variable, but usually much hairier on the lower stem. Its habitat is also quite variable: wet or dry prairie, sedge meadows, forest openings, willow thickets, bluffs, sand dunes, and the occasional roadside. It's a pretty grass and does well in cultivation. Plant some in your garden.
Please visit our sponsors
Where to buy native seed and plants ↓
- Kalm's Brome plant
- Kalm's Brome plants
- Kalm's Brome habitat
- lower sheaths are densely hairy
- mature spikelets
Photos by Peter M. Dziuk taken at Ordway Prairie in Pope County and in his garden.
Have you seen this plant in Minnesota, or have any other comments about it?