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Western Wetland Flora

Field Office Guide to Plant Species

Three-stamen Rush
Juncus ensifolius Wikst.

JPG -- Species Photo JPG -- Distribution Map

Family: Rush (Juncaceae)
Flowering: July-August
Field Marks: This rush has narrowly winged, flattened stems and bracts that are more than half the length of the inflorescence.
Habitat: Along streams, in marshes.
Habit: Perennial herb with creeping rhizomes.
Stems: Upright, flattened, narrowly winged, unbranched, up to 2 feet tall, smooth.
Leaves: Most of the leaves near the base of the plant, flattened and folded along the mid-vein, up to 15 inches long, up to 1/3 inch wide, partially septate, smooth.
Flowers: 4-25 borne in heads, the heads arranged in a panicle; each head spherical to hemispherical, up to 1/2 inch across, pale brown to dark brown to purple-black.
Sepals: 3, free from each other, up to 1/6 inch long, pointed at the tip.
Petals: 3, free from each other, up to 1/6 inch long, slightly shorter than the sepals, pointed at the tip.
Stamens: 3 or 6.
Pistils: Ovary superior, smooth.
Fruits: Capsules oblongoid, up to 1/6 inch long, about as long as the sepals and petals, rounded at the tip or with a short point, smooth.
Notes: This is an extremely variable species. Some plants have 3 stamens per flower, others have 6; some have few-flowered heads, others have many flowers; some have dark brown sepals and petals, others have light brown. The seeds are eaten by waterfowl.

Previous Species -- Drummond's Rush (Juncus drummondii)
Return to Species List -- Group 4
Next Species -- Long-style Rush (Juncus longistylis)

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Page Last Modified: Saturday, 02-Feb-2013 06:25:05 EST
Menlo Park, CA [caww55]