1. Nerisyrenia camporum (A. Gray) Greene, Pittonia. 4: 225. 1900.
Greggia camporum A. Gray, Smithsonian Contr. Knowl. 3(5): 9, plate 1. 1852; Parrasia camporum (A. Gray) Greene
Plants with woody caudex; moderately to densely pubescent or glabrate. Stems 1-6 dm, woody proximally, pubescent or glabrate with age. Cauline leaves: petiole 0.3-1.5 cm, often not sharply differentiated from blade, or (distal) sessile; blade usually obovate to spatulate or oblanceolate, rarely elliptic, 1-4(-4.5) cm × (4-)7-20(-30) mm (not fleshy), base attenuate, margins dentate, repand, or entire, apex acute to obtuse. Racemes 3.5 dm. Fruiting pedicels (rarely recurved), (7-)10-20 mm, densely pubescent. Flowers: sepals (spreading) oblong to oblong-lanceolate, 5-9 × 1-2 mm; petals obovate, (8-)10-14(-15) × 5-9 mm, claw (often flattened, margin dentate) to 2 mm; filaments 4.5-7.5 mm; anthers 2-3.5 mm. Fruits angustiseptate, 1.5-3 (-4) cm × 1.5-3(-4) mm; ovules 40-100 per ovary; style (1.5-)2-3.8(-4.3) mm. Seeds 0.8-1.1 × 0.5-0.7 mm. 2n = 18, 19, 21, 22, 27, 32, 34, 36, 40, 41, 58.
Flowering year-round, mostly Feb-Sep. Clay flats, gypseous clay, gravelly knolls, hillsides, sandy washes; 200-1300 m; N.Mex., Tex.; Mexico (Chihuahua, Coahuila, Durango, Nuevo León, Tamaulipas, Zacatecas).