Description
Three-flowered Rush is a small, tufted, grass-like perennial with stems that are 4-8 cm high. The basal leaves are 1-6 cm long, round in cross-section, and septate. Stem leaves are lacking. 2-4 flowers are borne in a solitary, terminal cluster, subtended by 2 brown, papery bracts that are as long as the head. Each flower is subtended by a single scale-like bract and has 6 tepals that are ca. 4 mm long with rounded tips. There are 6 stamens. The brown capsule is 5-7 mm high, rounded on top with a short beak, and exserted beyond the tepals. Each seed is 2-3 mm long with a narrow, papery wing on each end.
Diagnostic Characteristics
Of the small, high alpine rushes, JUNCUS CASTANEUS has larger flowers, J. BIGLUMIS has only 2 flowers and capsules that are indented on top, and J. ALBESCENS has bracts that are as long as the flower head, and mature capsules that are 3-5 mm long; ca. as long as the light brown tepals. A hand lens or microscope and technical key are needed for positive identification.