I don't think many perennials go dormant in summer...did you mean winter? Ephemerals go dormant in summer.
Ligularia is a good large leaved plant for shade. there is one called 'Chinese Dragon' that has very large serrated leaves and huge stems over 5 feet with yellow flowers. Rhodea has fairly large leaves and is evergreen. Acanthus mollis is another one. Hellebores have fairly large leaves. what zone are you in?

Good list above but the shredded umbrella plant, Syneilesis aconitifolia, will work as well......no summer dormancy :-) I would also add Rodgersia to the list and Astilboides.

lol I didn't know she was referring to Syneilesis.

Thanks for the replies! Good to know that it doesn't go dormant :)

If you mean the "Mayapple" spring ephemeral plant, yes, it is only really out in spring.

This isn't Mayapple. Shredded Umbrella Plant is the common name of Syneilesis aconitifolia, as gardengal48 posted above.

Okay, thanks Floral, sometimes I just read the other posts too fast, I've written down the plant name, I was going by a common name for Mayapple.