primrose, flowering plants of the genus Primula of the family Primulaceae, with 490–600 species, chiefly occurring in the Northern Hemisphere in cool or mountainous regions. The plants are low-growing, usually perennial herbs; a few are biennials. Most species grow 25 to 50 cm (10 to 20 inches) tall, but some are as short as 5 cm (2 inches) and others as tall as 1.2 metres (4 feet). Many species are cultivated for their attractive flowers.
The stalked leaves may be long and narrow or roundish and are crowded together. On the lower side the midrib is often prominent. The stalked flowers may be solitary, as in the common primrose (P. vulgaris), or more usually borne in loose umbels. The flowers have a tube with five spreading corolla and may be red, pink, purple, blue, white, or yellow.
The fairy primrose (P. malacoides) and the Chinese primrose (P. sinensis) are generally grown in greenhouses. The polyanthus hybrids, probably including P. elatior and P. vulgaris in their parentage, are popular garden plants. P. auricula, also perhaps hybridized, gave rise to innumerable varieties that were especially popular in the 17th century and later. Many other species and hybrids are grown in cool greenhouses, rock gardens, or borders.