New Zealand Bitter-cress - Cardamine corymbosa

A very small, low growing plant with typical Cardamine seedpods emerging from the flower before the petals have dropped. Inflorescence very few-flowered. The flowers are white with four petals and usually 6 stamens; larger than than Cardamine hirsuta or C flexuosa.  Leaves glabrous or sparsely hairy. .

Cardamine flexuosa and C hirsuta

Photo of open flowers showing number of stamens, and an indication of the size of the open flowers

It has spread as a horticultural contaminant and is naturalised on paths, cultivated ground, rockeries and in pavement cracks.

It has quite a long flowering period from March or April through to autumn.

It is usually annual but sometimes behaves as a perennial. It reproduces by seed and also by leaf-tip rooting.

First found in the British Isles in 1985 and spreading. 

Rarely recorded in Leicestershire and Rutland but possibly under recorded and more frequent than records suggest.