Cactolith

"A cactolith is a quasihorizontal chonolith composed of anastomosing ductoliths whose distal ends curl like a harpolith, thin like a sphenolith, or bulge discordantly like an akmolith or ethmolith."

This term and its associated definition were created by Charles B. Hunt, a USGS researcher, in his paper "Geology and geography of the Henry Mountains region, Utah" (1953). Whilst he was in fact describing an actual geological feature - a laccolith which he saw as resembling a cactus [http://www.findarticles.com/p/articles/mi_m0GDX/is_4_78/ai_104522725] - he was also, tongue-in-cheek, commenting on what he saw as an absurd number of "-lith" words in the field of Geology.