Primulina gemellaPrimulina gemella is a plant in the family Gesneriaceae, native to Vietnam. The species was formerly placed in the genus Chirita.DescriptionPrimulina gemella grows as a perennial herb, with a rhizome measuring up to long. Its leaves are dark green above, whitish green below and measure up to long. Mauve flowers grow singly, only the type specimen had an inflorescence.Distribution and habitatPrimulina gemella is endemic to Vietnam, where it is confined to the islands of Hạ Long Bay, a UNESCO World Heritage Site. In 2000, the species was considered confined to a single island, but by 2012 had been found on numerous islands. Its habitat is on soil-covered limestone rocks.