I know they can go brown and very scruffy looking, whether its rust or not. What are you looking for - ground cover or something yellow?

Thanks for answering. Ground cover mainly. I have an ancient hedge whose understory is empty and open to weeds. I hoped that this species would do the trick as it exists naturally in other similar hedges locally. Does it just drop its leaves in winter ?

I can't remember whether it loses them all but they do get very untidy looking. I have a good clump of Iris foetidissima growing under a conifer hedge successfully on the north side. Also a pulmonaria which does keep its leaves and an arum maculatum and a fern or two. These don't spread much though.

Thanks very much