Annual or perennial herbs, shrubs, trees, or lianas, often with glandular dots or streaks in lines on leaves, stems and floral parts. Leaves alternate and spiral, opposite or whorled, often forming a basal rosette 9when plants herbaceous), simple, entire, rarely lobed, with pinnate venation, stipules absent. Inflorescence determinate or indeterminate, in axillary or terminal panicles, umbels, racemes, heads, or solitary, each subtended by 1 or more bracts Flowers bisexual or unisexual and then plants dioecious, in axillary or terminal panicles, umbels, racemes, heads, or solitary, each subtended by 1 or more bracts; sepals (3–)4–5(–9), in axillary or terminal panicles, umbels, racemes, heads, or solitary, each subtended by 1 or more bracts, free or connate; petals usually present, (3–)4–5(–9), connate; stamens (3–)4–5(–9) , opposite the petals (or alternating with sepals if petals absent), anthers opening by longitudinal slits or sometimes apical pores, staminodes sometimes present; carpels usually 3–5; ovary usually superior or half-inferior, unilocular but sometimes with 5 incomplete internal partitions, style solitary, usually with a capitate stigma, ovules usually numerous. Fruit a capsule dehiscing via valves or sometimes circumsciss, or a berry, or a drupe. Seeds angled.
Rarely cultivated genera: Soldanella L. occasionally cultivated as S. alpina L. from the European Alps and distinguished by the fringed petal lobes; and Samolus repens (J.R & G. Forst.) Pers., Creeping Brookweed, a native Australian marsh plant that is distinguished by its partly inferior ovary and alternation of sterile and fertile stamens.
Primulaceae can be recognised by their usually spirally arranged leaves that often have dark dots or lines. Petals usually fused, with the stamens being opposite the petals and the ovary has free-central placentation with several to many ovules; the stigma is not lobed.
Cosmopolitan. c. 58 genera, and 2590 genera, 10 genera and c. 35 species in Australia.
Source: (1997). Primulaceae. In: . Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.
Updated by: Val Stajsic, March 2018