macrospore
/ˈmakrə(ʊ)spɔː/noun
1 Botany and Mycology. The larger of the two types of spore produced by a heterosporous plant (now usually called megaspore).
2 Biology. A large spore (usually the larger of two types of spore) produced by various protoctists.
Origin
Mid 19th century; earliest use found in Todd's Cyclopaedia of Anatomy and Physiology. From macro- + spore. Compare French macrospore.