Flowering from May to June.
Primula atrodentata is close relative of Primula erythrocarpa, but differs from the latter in its flowering scapes 4-8 cm tall (vs. 10-30 cm), leaves with fine scabrous glandular hairs (vs. with white septate hairs).
Primula atrodentata is occurring in SE Xizang of China, Bhutan, India, Nepal, Sikkim.
Herbs perennial, lacking basal bud scales at anthesis. Leaves forming a rosette; petiole nearly obsolete to occasionally nearly as long as leaf blade; leaf blade elliptic to oblong or spatulate, 1.5-5 cm long, 0.5-2 cm wide, tapering to base, minutely glandular, abaxially occasionally white or pale yellow farinose, margin denticulate, apex rounded to obtuse. Scapes 4-8 cm tall, up to 18-28 cm in fruit, yellow farinose toward apex; umbel capitate, many flowered; bracts linear-lanceolate, ca. 3-5 mm, base gibbous, apex acute. Pedicel nearly obsolete or to 1 mm. Flowers heterostylous. Calyx campanulate, 5-8 mm, glandular or scarcely farinose, parted slightly below middle; lobes lanceolate, usually tinged with purple at apex. Corolla mauve or pale blue-violet, with a white eye; tube ca. 2 times as long as calyx; limb 10-15 mm wide; lobes broadly obovate, deeply 2-lobed. Pin flowers: stamens near base of corolla tube; style ca. half as long as tube. Thrum flowers with positions reciprocal. Capsule subglobose, shorter than calyx.
The chromosomal number of Primula atrodentata is 2n = 22 (Sakya and Joshi, 1990).
Growing in moist meadows, among shrubs; 3600-4600 m.