This Is Why Some Cactus Spines Are So Hard — and Painful — to Remove

As anyone who’s gotten too close to a jumping cholla cactus can attest, the experience is singularly painful — and difficult to resolve, as the cactus’ spines are particularly stubborn to remove.Cactus spines have many functions, from protection to the collection of vital water in dry climates, but some are so much harder to remove than others. Now researchers have found out why.Microstructure Matters
Stephanie Crofts and Philip Anderson of the University of Illinois