Herbs, annual, low, usually glaucous, glabrous, taprooted, rosulate. Leaves in a basal rosette, lanceolate, oblanceolate, to narrowly obovate in outline, imparipinnate with deeply divided segments. Flowers in long pedunculate dichasia from rosette, bisymmetric. Petals 4, yellow, white, or bluish pink; outer petals flat, shallowly 3-lobed to entire; inner petals deeply 3-lobed; lateral lobes oblong, entire; median lobe with a narrow base and a rounded to oblong limb with a fimbriate or ± denticulate margin, specialized for secondary pollen presentation, initially pressed to stamens/gynoecium. Stamens 4, each with 2 thecae, but median ones with 2 vascular bundles, lateral ones with 1 vascular bundle; filaments flat, ± translucent, with lateral basal nectaries; anthers oblong, extrorse. Style with 2 narrow commissural stigmatic branches. Fruit linear, with many seeds in 1 row, dehiscing with 2 valves or breaking up into 1-seeded units. Seeds flattish, covered with oxalate crystals. Pollen with 2 long colpi, sometimes fused into a synaperture. Chromosome base number = 8.