English: Chestnut rush.
Region: circumpolar, Northern Hemisphere, Europe, Asia, North America.
Botany: widespread; perennial; habitat wet areas, streambanks, bogs, seeps; stems up to 50 cm high, singly or in pairs, from a rhizome; leaves few longest basal ones reaching 20 cm long; flowers five flower heads, each containing ± 10 flowers, 3 brown tepals, 6 stamens; fruit is a dry, dark brown, chestnut capsule; seed small, 5 mm, including its long tail; reproduces by seed and by rhizome.