rock brake

noun

any of various ferns of the genera Pellaea and Cryptogramma, which grow on rocky ground and have sori at the ends of the veins

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Examples from the Web for rock brake

Historical Examples of rock brake

On the same cliff were tufts of the alpine woodsia and dense patches of rock-brake—but these stand in no need of the bee.
In the Open
Stanton Davis Kirkham