McCart's nailwort

Plants perennial; taproot ± stout. Stems sprawling, branched from base, 3-10 cm, puberulent. Leaves: stipules lanceolate, 2.5-5 mm, apex narrowly acuminate, entire; blade linear-oblong to linear-lanceolate, 2-10 × 0.7-1.5 mm, leathery, apex spinose, minutely puberulent. Cymes terminal, 10-20-flowered, congested, in clusters 0.5-1.5 mm wide. Flowers 5-merous, extended-urceolate, with enlarged hypanthial bulge and calyx cylindric to slightly tapering distally, 3.5-4 mm, moderately pubescent proximally, with minute, hooked hairs on hypanthial bulge, sparsely pubescent on calyx, densely so with hooked to coiled hairs on hood; sepals green to red-purple, midrib apparent, oblong, 1.9-2.1 mm, herbaceous to leathery, margins white, 0.2-0.3 mm wide, papery, apex terminated by awn, hood triangular-rounded, awn erect, becoming widely divergent, white, ± lanceoloid from proximal constriction, 0.8-1.3 mm, slightly scarious, distinct spine absent; staminodes narrowly subulate, 0.6-0.8 mm; style 1, cleft in distal 8, 0.7-0.8 mm. Utricles unknown.

Flowering spring. Dense red sands; of conservation concern; 200-300 m; Tex.

Paronychia maccartii is still known only from the type collection in Webb County.