how old are cinammon ferns? mgnv.org glochid or glochidium: small barbed hair (modified spine) found only on members (like prickly-pears and chollas) of the cactus subfamily opuntioideae.spine: a modified, sharp, pointed leaf. Category:gardening Global Rank:1,997,406 visits:18.9K pages/Per:1.8 ADS