The corolla is blue-purple, 4.5-6 mm long, with a short tube nearly equaling the calyx, and a limb diameter of 4-6 mm. The lobes are nearly square or slightly inverted-ovate to elliptic, 2-lobed at the apex.
The calyx is cup-shaped, 3-3.5 mm long, glandular on the outside, often purplish-black. It is split to the middle or slightly beyond, with rectangular to lanceolate or narrowly elliptic lobes, acute or obtuse at the apex, sometimes with small teeth.
It flowers in July.
Primula sapphirina