in botany, "a spore of large size compared with others," 1859, from macro- "large" + spore (n.).
Entries linking to macrospore
macro-
word-forming element meaning "long, abnormally large, on a large scale," taken into English via French and Medieval Latin from Greek makros "long, large," from PIE root *mak- "long, thin."
spore n.
"reproductive body in flowerless plants corresponding to the seeds of flowering ones," 1836, from Modern Latin spora, from Greek spora "a seed, a sowing, seed-time," related to sporas "scattered, dispersed," sporos "a sowing," from PIE *spor-, variant of root *sper- "to spread, sow" (see sparse).