Perhaps I should collect this in autumn and put it under my pillow!
Sometimes in late summer a spherical red fibrous growth can be found on the stems of wild roses. It is a Robin’s Pincushion  (Bedeguar Gall) and caused by the larvae of a tiny gall wasp which hatch from eggs laid by the wasp in buds or leaves in spring.  Instead of developing normally into shoots and leaves, a gall grows into a hard woody structure covered with hairy growths with a number of chambers inside in which the grubs grow during the winter.  The fibres drop off during autumn leaving the wooden gall which was considered useful in the past to prevent or cure several ailments.
According to folklore, a gall hung around the neck or hung up in the house was considered to prevent whooping cough, or it could cure toothache if “you wear it in your boasom.”  By carrying ones in a pocket it could prevent rheumatism or by placing it under the pillow it could cure insomnia.  One of its alternative names was “save-whallop” because boys sometimes put it in their coat cuffs ‘as a charm to prevent flogging.”   Although there is much to commend some old folk remedies, I doubt if anyone now would collect a rose gall.