Herbs, annual, cespitose, 0.07--0.6 dm. Culms to 160. Leaves to 1.5 cm x 0.1--0.3 mm. Inflorescences 1(--2) flowers; bracts subtending inflorescence 2, round to acutely ovate, inconspicuous, 0.4--1.6 mm, membranous. Flowers: tepals pale yellow-green until seeds ripen, tip darker, 1.6--3(--4.2) mm; ; outer and inner series nearly equal or outer slightly longer; stamens 2--3, filaments 0.6--0.9 mm, anthers 0.3--0.5 mm; style 0.2--0.4 mm, stigma 0.6--1.1 mm. Capsules pale yellow-green to reddish tinged until seeds ripen, 3-locular, ovoid to ellipsoid, 1.3--2.9 ã 0.9--1.6 mm. Seeds globose-ovoid, 0.3--0.4 mm. n = 16. Flowering and fruiting spring-- to early summer. Wet sandy soil of seepage areas on sandstone, depressions in meadows, vernal pools, and streamsides; 300--1900 m; Calif. Juncus luciensis occurs in California in the Diamond and Santa Lucia mountains and the Transverse and Peninsular ranges.