Description
Hall's Rush is a perennial with erect stems that are 20-30 cm tall. The leaves, which are confined to near the base of the plant, are round and up to 15 cm long with a groove on the side facing the stem. The uppermost leaf has a sheath surrounding the stem but lacks a blade. The 2-6 flowers are borne in a loosely congested inflorescence subtended by an erect leaf, or bract. Because this involucral leaf is erect and round, it seems to be lateral rather than terminal. The flowers have 6 undifferentiated, sharply pointed perianth segments that are light brown with membranous margins and 4-5 mm long. The seed capsules are dark brown with a lobed top. Each seed is ca. 1 mm long with a distinct tail at each end.
Diagnostic Characteristics
JUNCUS is a large and difficult genus to distinguish, so a technical key should be consulted. Mature fruit is necessary for positive determination. The apparently lateral inflorescence, lack of an upper leaf blade, lobed seed capsule, and tailed seeds should help distinguish this species.
Habitat
Dry, wet, and boggy meadows, margins of ponds and lakes, and along streams at 2775 to 3350 m (Welsh, 1993).