Sedges (Carex) are the primary hosts, bearing uredinia and telia.   The alternate host carrying the aecia are species of Ribes.  Uredinia are light brown, on yellowish spots; telia are blackish-brown.  This is not described as a gall-causer in Redfern & Shirley (2023).

This is a complex of species without a clear consensus; some authors describe different species depending on the species of Carex affected;  Puccinia caricina is best regarded as sensu lato.   There are slight differences in uredinia and telia on different Carex species.  Refer to Plant Parasites of Europe website for details.  The species within the complex include the following, which may be present in VC55; microscopic examination may be needed to confirm identification:

• on Carex pendula - P ribesii-pendulae or ribis-pendulae
• on Carex flacca - Puccinia ribesii-diversicoloris 
• on Carex riparia/acutiflorus - Puccinia magnusii
• on Carex paniculata - Puccinia ribis-nigri-paniculatae
• on Carex nigra/acuta - Puccinia pringsheimiana

host (as species complex)

Photograph the rust on the host.  Ensure you have noted the host-plant species in your comments

alternating between a Ribes and a Carex species