Described from western Sikkim, this efarinose species is distinguished by having small tubular flowers with the petals in line with the corolla tube on usually one umbel but sometimes two superimposed. Leaves are oblong-obovate, round at the apex and erose-denticulate at the margin with the teeth terminating in hydathodes. Primula prenantha has a large distribution and is uniform in appearance except in SE Tibet where possible intermediates with Primula morsheadiana or Primula polonensis occur, both species with larger, campanulate flowers. Primula microloma is a white flowered form collected once on the Salween-Irrawady divide.