protocorm
/ˈprəʊtə(ʊ)kɔːm/Botany
noun
In clubmosses and orchids, which grow in association with mycorrhiza: a tuberous body, with rhizoids, representing the embryonic plant and giving rise to primordial leaves.
Origin
Late 19th century; earliest use found in Frederic Bower (1855–1948), botanist. From proto- + corm, after French protocorme.