The New Zealand Plant Conservation Network

I would like to know in laymen terms the key difference between Cardamine corymbosa and Cardamine hirsute

Hi David, Cardamine corymbosa is a variable species and also includes some distinct groups that are likely to be named as species, so clear differences between C. hirsuta are not clear-cut, but mainly if the leaves on the flowering stem are of a very different shape than the leaves at the base of the plant, then it is one of the exotic Cardamine species such as C. hirsuta, rather than a native species such as C. corymbosa

Cardamien hirsuta is (as the name tells you) 'hairy'. Its a much bigger plant than any of the C. corymbosa complex, has pinnatifid, hairy leaves, and very conspicuous white flowers. C. corymbosa agg - have leaves in threes (usually) and are not or only very rarely (and then finely) hairy. In gardens C. hirsuta is very common, and the race of C. corymbosa seen there is minute with leaves ALWAYS in threes, and the flowers have minute (often absent petals). Hope that helps.

Thank you both for your reply Peter and Mike, I went to the Auckland Museum Herbarium and keyed it out. It appears to be C. debilis agg. Cheers