Brachyelytrum aristosum (Northern Shorthusk)
|Also known as:|
|Habitat:||part shade, shade; moist to dry; woods, thickets|
|Fruiting season:||July - September|
|Plant height:||12 to 36 inches|
|Wetland Indicator Status:||none|
|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.
Loose, erect to nodding, branching cluster at the top of the stem, 3 to 7 inches long, very slender in outline, the branches appressed, with 1 to 3 spikelets (flower clusters) per branch, occasionally 4 or 5. Spikelets are loosely overlapping at the tip of a branch, short-stalked, narrowly lance-elliptic in outline and have a single floret.
At the base of a spikelet is a pair of bracts (glumes), both hairy, the lower glume egg-shaped and less than 1 mm long, often obscure and sometimes absent; the upper glume lance-shaped to triangular with a blunt tip, up to 3 mm long. Florets are surrounded by a pair of bracts (lemma and palea), the lemma narrowly elliptic, the body 9 to 10 mm (~3/8 inch) long, tapering to a straight awn 14 to 26 mm (½ to 1 inch) long, 5-veined, variously covered in short, stiff hairs especially along the veins, the hairs less than .2 mm long; the palea is 7.7 to 11.5 mm long, hairless and 2-keeled, the keels forming 2 teeth at the tip. Arising from the base and running along the palea is a naked stalk (rachilla) extension, more than half as long as the palea.
Leaves and stems:
Leaves are 3 to 6 inches long, 8 to 16 mm (1/3 to 2/3 inch) wide, lance-linear, flat, sparsely long-hairy on the lower surface, sparsely long-hairy along major veins on the upper surface, and sparsely long-hairy along the edges. Leaves are initially erect, becoming ascending to widely spreading. Venation is distinct, with numerous cross veins between the lateral, parallel veins.
The sheath has thin, papery edging and is covered in long, spreading hairs. The ligule (membrane where the leaf joins the sheath) is 1.8 to 2.5 mm long, pointed or notched at the tip and not fringed with hairs. Nodes are densely short-hairy. Stems are hairless to sparsely hairy, usually more densely hairy near the nodes, unbranched, mostly erect, multiple from the base and forming loose clumps from short, knotty rhizomes.
Spikelets are light brown at maturity, the florets shedding individually as each grain matures, leaving the tiny glumes behind on the stalk. Grains (seeds) are brown, 5.5 to 7.5 mm long, linear with an abrupt taper to a distinct beak about 1 mm long.
Northern Shorthusk is fairly common, cool-season grass of woodlands and mixed forests, and reaches the southwestern edge of its range in Minnesota. The leaf venation is diagnostic for Brachyelytrum species and distinguishes it from other species with similar forms, such as Bromes (Bromus spp.), which have multi-flowered spikelets, and Black-fruited Rice Grass (Patis racemosa/Piptatherum racemosum), which has longer, arching leaves, usually spreading panicle branches, blackish lemmas, and hairless, weakly-veined glumes as long as the spikelet (excluding the awns). The only other Brachyelytrum species in North America, including Minnesota, is Bearded Shorthusk (B. erectum); the two were once considered a single species and older references do not separate them. B. erectum has lemmas with more prominent veins and visibly longer hairs (.5 to 1mm long) as well as slightly longer ligules (2 to 3.5mm), a slightly longer lemma body (to 13mm) and slightly shorter awn (usually 17mm or less), though there is overlap on these last 3 traits and determining where the lemma body ends and the awn begins is a bit subjective. The lemma hairs are probably more consistently reliable. In Minnesota, B. aristosum is mostly in the northern half of the state where B. erectum is mostly in the southeast quadrant, which may also help distinguish them.
Please visit our sponsors
Native Plant Nurseries, Restoration and Landscaping Services ↓
- Northern Shorthusk plants
- Northern Shorthusk plants
- erect leaves emerging in spring
- Brachyelytrum leaf venation
- comparison of Brachyelytrum ssp. and Patis racemosa spikelets
Photos courtesy Peter M. Dziuk taken in Anoka and Pine counties. Photo of Brachyelytrum leaf venation ? Fontenelle Nature Association, used by permission.
Have you seen this plant in Minnesota, or have any other comments about it?