A white blister rust affecting Hairy Bittercress Cardamine hirsuta.

Similar species in the Albugo candida s.lat. species complex affect different species of crucifer in the Brassicaceae family

host

Photograph the fungus on the host plant; ensure you have identifed the host and made a note of this in the comments.  If you are not sure of the host species, record it as Albugo candida s.lat.

On Hairy Bttercress; waste gound, gardens, parks, etc.

Albugo candida has recetly been split into a number of species, depending mainly on host.  See Chater et al (2020) for more details