Description from Flora of China
Herbs perennial or annual, rarely suffruticose. Leaves alternate, opposite, or whorled, often all basal, simple, entire to lobed. Flowers solitary or in panicles, racemes, or umbels, usually with bracts, perfect, (4- or)5(--9)-merous, often heterostylous (Primula). Calyx persistent. Corolla gamopetalous, actinomorphic, rarely absent (Glaux). Stamens as many as and opposite corolla lobes, ± epipetalous, occasionally with scalelike staminodes. Filaments free or connate into a tube at base. Ovary superior, rarely semi-inferior (Samolus), unilocular; placentation free central; style simple; stigma inconspicuous, capitate. Fruit a capsule, dehiscing by valves, rarely circumscissile or indehiscent. Seeds many or few; embryo small, straight, surrounded by endosperm.
The family contains 22 genera and ca. 1000 species, occurring mainly in temperate and mountainous regions of the northern hemisphere. Twelve genera and 517 species are widely distributed throughout China, but are represented mostly in the S and W regions. The centers of diversity for Primula, Androsace, and Omphalogramma are W Sichuan, E Xizang, and NW Yunnan. Lysimachia is also highly developed in provinces S of the Chang Jiang, while Pomatosace is an endemic genus confined to a small area of NW Sichuan and Qinghai.
Many species of Primula and Androsace are cultivated for their attractive flowers as pot plants, in rock gardens, or in garden borders. Some species of Lysimachia are used medicinally. Cyclamen persicum Miller is frequently cultivated as a pot plant.
Chen Feng-hwai, Hu Chi-ming, Fang Yun-yi, Cheng Chao-zong, Yang Yong-chang & Huang Rong-fu In Chen Feng-hwai & Hu Chi-ming, editors. 1990. Primulaceae (1). Fl. Reipubl. Popularis Sin. 59(1): 1-217; Hu Chi-ming In Chen Feng-hwai & Hu Chi-ming, editors. 1990. Primulaceae (2). Fl. Reipubl. Popularis Sin. 59(2): 1-321.
(Authors: Hu Chi-ming; Sylvia Kelso)