Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
61. Juncaceae, the Rush Family
1. Juncus L. -- Rush
1. Juncus alpinus Vill. -- Alpine rush
Rhizomatous perennial growing in small tufts, 1.5-4 dm tall. Leaves mostly
basal, 1 or 2 cauline; blades terete, hollow, nodulose-septate, 0.5-1(1.5)
mm wide when pressed; sheaths green or often reddish on basal leaves,
the margins membranous, shiny, often yellowish, projecting into auricles
0.5-1 mm long at the summit of the sheath. Inflorescence slender, 2-15
cm long, sparsely to freely branched, the branches spreading to usually strongly
ascending; glomerules often rather few, obpyramidal, 3- to 12-flowered.
Flowers green to light or dark brown, 2-3 mm long; tepals acute
to obtuse or mucronate, the inner ones shorter, broader and tending to be more
obtuse than the outer, their margins scarious; stamens 6. Capsules
oblong, 1-locular, surpassing the perianth, rounded below the apiculate apex;
seeds cylindric-ellipsoid to ovoid-ellipsoid, pale brown to brown, ca.
0.5 mm long. Jul--Sep. Springs, shores, stream banks, fens and boggy places,
where water is fresh; occasional, mainly in the n part and the NE Sand Hills;
(Circumboreal, in N.Amer. s to PA, IN, MO, NE, CO, UT, ID and WA).
A sterile hybrid between this species and J. nodosus, called J.
X nodosiformis Fern., has been found in a series of fens in Deuel Co.,
SD. It is clearly intermediate between the parental species and has abortive
ovules and pollen. It may be expected in other places where J. alpinus
and J. nodosus occur together.
Return to Family -- Juncaceae - The Rush Family
Next Section -- Juncus articulatus L. -- Jointed
rush
U.S. Department of the Interior |
U.S. Geological Survey