General Species Description
- The grooved rush is a perennial, native, emergent plant growing to a height of 30-90 cm. This species has creeping rhizomes and grows in strong tufts. Grooved rush has lateral inflorescence (involucral bract appears to be a continuation of the stem). The involucral bract is generally one third as long as the stem and end in a sharp point. The stem is blue-green and round, bearing brownish, loose, pointed sheaths.
Leaves
- The leaves of the Juncus patans are reduced and bristle-like, if they are present at all.
Inflorescence/Flowers
- Grooved rush appears to have lateral inflorescences because the involucral bract, which is round and erect, appears to be a continuation of the stem. The inflorescence is 2.5-9 cm in length and are open with more than 20 flowers. Individual flowers have tepals (2-3.5 mm) which are greenish or brown, needle-like, stiff, with transparent margins spreading away from the the capsule. The capsule is almost as long as the tepals and appears enlarged and round. This species usually has 6 stamens. Blooms June through August.
Fruits
- The seeds are an oval shape and have a distinctive ridge along the entire length..
Habitat
- Juncus patans can be found primarily in saturated soils on the westside of the Cascades in Oregon.