Perennial erect herb, 30-71(-75) cm high. Rootstock thick, ± creeping, producing a terminal flowering stem every year, rarely with several stems at the same time, leaves 2(-3) pinnate, a single basal leaf present in the young plant, later with cauline leaves; ovate to ovate-lanceolate, acute, acuminate, irregularly dentate to ± regularly serrate-dentate; glabrous or slightly hairy along the veins on the lower surface. Inflorescence arranged in an oblong to ovoid raceme, which may become shortly cylindrical after flowering. Sepals small, white rarely purplish outside, concave. Petals (nectarines, called staminodes by some authors) shorter than the ovary or slightly longer, ovate to elliptical or spathulate, acute or obtuse. Berry black.