The Collaborative International Dictionary
Primulaceous
Primulaceous \Prim`u*la"ceous\, a. (Bot.) Of or pertaining to an order of herbaceous plants ( Primulace[ae]), of which the primrose is the type, and the pimpernel, the cyclamen, and the water violet are other examples.
Wiktionary
primulaceous
a. (context botany English) Characteristic of the primrose and other plants of the order ''Primulaceae''