Northern Prairie Wildlife Research Center
Southern Wetland Flora
Field Office Guide to Plant Species
Juncus repens Michx.
- Family: Rush (Juncaceae)
- Flowering: June-October
- Field Marks: This small, annual rush is often found growing in shallow standing water. Its
flowers are borne in clusters and not singly, and its petals are 1/4-1/2 inch long, much longer
than the petals of any other annual rush.
- Habitat: Ditches, swamps, peaty margins, ponds and pond margins, lakes, drainage canals, often in
shallow standing water.
- Habit: Sometimes annual but usually perennial herb with fibrous roots, but forming dense mats by a
flat, black rhizome which may be above or below the soil's surface when growing in water.
- Stems: Tufted when growing on land, creeping and rooting at the nodes when growing in water, slender,
- Leaves: All basal, linear, elongated, soft, flat, smooth; sheaths flattened.
- Flowers: Borne in heads in cymose clusters, each head with 5-15 flowers.
- Sepals: 3, green turning brown, narrowly linear, long-pointed at the tip, up to 1/3 inch long.
- Petals: 3,
green turning brown, narrowly linear, long-pointed at the tip, up to 1/4-1/2 inch long, always longer
than the sepals.
- Stamens: 3.
- Pistils: Ovary superior.
- Fruits: Capsules narrowly lanceolate, brown, smooth, 1/6-1/4 inch long, much shorter than the
subtending petals; seeds many, dark brown, oblong to oval but asymmetrical, finely net-veined.
- Notes: This species will form extensive mats when growing in water, and often overwinters in this
condition. Flowering usually occurs only after the water recedes.
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Next Species -- Needle-pod Rush (Juncus scirpoides)