Description from
Flora of China
Herbs perennial. Basal bud scales ovate to ovate-oblong, to 5 cm, yellow farinose. Petiole broadly winged, concealed by basal bud scales at anthesis, becoming diffuse, ca. as long as leaf blade; leaf blade oblanceolate to obovate or oblong, 5--20 X 1--2.5 cm at anthesis, to 30 cm at fruiting, efarinose or yellow farinose abaxially, base attenuate to obtuse or shallowly cordate, margin crenate to denticulate, apex obtuse to acute. Scapes 7--18 cm at anthesis, elongating to 35 cm in fruit, yellow farinose distally, umbels 6- to many flowered; bracts lanceolate, 3--10 mm. Pedicel 1--2 cm, farinose. Flowers heterostylous. Calyx campanulate, 5--7.5 mm, densely yellow farinose, parted to middle; lobes ovate to ovate-oblong, margins overlapping, apex obtuse. Corolla yellow; tube 1.1--1.3 cm; limb 1.5--2.5 cm wide; lobes suborbicular, margin crenate to emarginate. Pin flowers: stamens at middle of corolla tube; style slightly exserted. Thrum flowers: stamens toward apex of corolla tube; style slightly longer than calyx. Capsule disintegrating at maturity.
J. Richards (J. Scot. Rock Gard. Club 15: 211. 1977.) treated this species as a subspecies of Primula calderiana I. B. Balfour & Cooper because the plants hybridize freely in cultivation. As is well known, species will maintain their integrity in geographic isolation, but may produce hybrids in areas where they overlap with other closely related species. The experienced collector F. Ludlow made a very convincing argument in a field note in 1949, when he collected these two species in Monala, on the Karchung pass of Bhutan: "Above ca. 14000 ft., P. calderiana here ceases, and is completely replaced by this plant (P. strumosa). A few miles below where this was taken, every color imaginable exist. At 15000 ft. there is nothing but this one color (rich yellow). There is no doubt that P. calderiana and P. strumosa hybridize freely". This taxon is sufficiently distinctive to justify recognition at the species level.
Alpine meadows, Abies and Rhododendron forests, margins of Abies forests; 3500--4300 m. S Xizang [Bhutan, Nepal].