Smooth-seeded rush

Juncus leiospermus var. ahartii Ertter

Herbs, annual, cespitose, 0.2--1.2 dm. Culms to 100, (0.2--)0.4--0.8 mm diam.. Leaves 1/3--3/4 height of plant. Inflorescences terminal clusters, each with 1--7 flowers; bracts subtending inflorescence 2--8, round to acutely ovate, inconspicuous, 0.7--2.4 mm, membranous. Flowers: tepals reddish to black, narrowly lanceolate to oblong, 2--4.6 x 0.5--1.4 mm; inner series usually slightly longer than outer, apex obtuse to acuminate; stamens 3, filaments 0.5--1.4 mm, anthers 1--3.2 mm; style persistent, 1.4--4 mm, stigma 1.3--4 mm. Capsules reddish, 3-locular, globose to ellipsoid or oblong, 2--4.5 x 1--3 mm, nearly equal to sepals. Seeds ovoid, 0.35--0.45 mm. n = 16.

Flowering and fruiting in spring. Margins of vernal pools; of conservation concern; to 500 m; Calif.

Plants from Butte and Calaveras Ccounties, California, tend to be smaller and consistently develop only one flower per culm; they may be recognized as Juncus leiospermus var. ahartii Ertter.