Since you mention Cheilanthes ferns Palustris, a few members have said that they know little or nothing of ferns and most people think that ferns need shady, rather damp places I thought that I should mention the fact that there are ferns that prefer virtually the extreme of this. There's quite a number of ferns that have adapted even to desert conditions and so quite happily grow in full sun and where there is almost no soil on walls and in rock crevices, hollow logs etc. These being known as Xerophytic (arid loving) ferns. Cheilanthes are good examples of the type. In very hot and arid conditions (not much chance of that in this country!) some might shrivel and look dead but spring to life with a few drops of rain. Examples are Cheilanthes tomentosa (Woolly Lip Fern) growing 8-14", Ch. sinuata (Wavy Cloak Fern) 6-18", Ch. argentea (Silver Cloak Fern) 4-6".
Examples of other ferns of this type: Adiantum aethiopicum (Common Maidenhair), A. formosum (formosum meaning 'beautiful'), A. hispidum, the Rasp ferns (Doodias), the Leather Fern Ruhmohra adiantiformis (flower arrangers like this one since it lasts very well in arrangements. It grows naturally on coastal rocks in full sun).
They are hardy but do need excellent drainage since they can't stand cold AND wet.
Might be an interesting proposition for members who have dry, sunny spots where builders have dumped rubble etc.
