1. Paronychia ahartii Ertter, Madroño. 32: 87, fig. 1. 1985.
Plants annual; taproot filiform to stout. Stems erect, tightly branched, 0.5-1.2 cm, glabrous. Leaves: stipules broadly ovate, 3-6 mm, apex acute to acuminate, entire; blade linear to oblance-olate, 2.5-7.5 × 0.5-1.2 mm, leathery, apex spinulose, glabrous. Inflorescences: flowers axillary, solitary. Flowers 5-merous, cylindric, with enlarged hypanthium and calyx cylindric to somewhat tapering distally, 4.2-5 mm, moderately hairy in proximal 1/ 2 with hooked to coiled hairs; sepals green to tan, veins absent, lanceolate to elliptic, 3.5-4.5 mm, margins translucent, 0.7-1+ mm wide, scarious (resembling stipules), apex (of herbaceous midrib) terminated by awn, hood apparently consisting of prominent, erect, scarious extension of margins split at apex, awn ± spreading, 1.5-2 mm, oblong extension of midrib in proximal 1/ 4, with white, wavy, threadlike spine; staminodes filiform, ca. 1 mm; style 1, cleft in distal 4, ca. 0.5 mm. Utricles ovoid, ca. 1.3 mm, papillose distally.
Flowering spring. Well-drained rocky outcrops, vernal pool edges, volcanic uplands; of conservation concern; 0-500 m; Calif.
Paronychia ahartii, first collected in 1938, is known from three counties in north-central California. It most closely resembles P. arabica (Linnaeus) de Candolle, a species of northern African and Arabian deserts.