"In certain vascular plants, especially ferns: any of the vascular bundles comprising a dictyostele", Late 19th cent.; earliest use found in Sydney Vines (1849–1934), botanist. Apparently irregularly from ancient Greek μερίς part + stele.[meristele etymology, meristele origin, 英语词源]
"A type of stele found in certain vascular plants (especially ferns) which is broken up into a network of meristeles separated by parenchymatous areas usually associated with leaf-gaps", Early 20th cent. From dictyo- + stele.