E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Hearts Ease.
The viola triclor. It has a host of fancy names; as, the Butterfly flower, Kiss me quick, a Kiss behind the garden gate, Love in idleness, Pansy, Three faces under one hood, the Variegated violet, Herba Trinitatis. The quotation annexed will explain the popular tradition of the flower: