Collinsia heterophylla is a native Californian wild flower that grows in partial shade under oaks and other trees at the edge of woods. It is a member of the Schropulariaceae family (figworts) that includes foxgloves and antirrhinums.
Common names include innocence, blue-eyed Marys and Chinese houses, the latter because the flowers form in tight whorls of decreasing diameter which give the plant the appearance of a pagoda. The overall height of this plant is usually around 40cm, depending on the soil. They prefer a rich loam but will grow in most soils. The flowers are similar to those of the antirrhinum (snapdragon) and have a lilac or white upper lip and a rose, purple or violet lower lip. They attract lots of bees and butterflies.
The leaves of Chinese houses are bright green and lance-shaped and the whole plant is covered with a velvety fuzz like the skin of a peach.
Unfortunately it is not drought or frost resistant and needs regular watering during dry spells. It is best treated as an annual and will seed itself around the garden. Alternatively the seed can be collected and sown in early spring. It doesn't need to be covered with soil; just sprinkle on the surface and press down lightly.
The genus name Collinsia is in honour of Philadelphia botanist and Quaker, Zaccheus Collins (1764-1831). The specific epithet 'heterophylla' refers to the fact that the same plant has two types of leaves, some with smooth edges and others finely serrated. An added attraction is that the leaves turn a rich crimson at the end of the reproductive cycle.
Flowering usually finishes in early autumn but regular dead-heading, before the fruit sets, will prolong flowering.