The Collaborative International Dictionary
Seirospore
Seirospore \Sei"ro*spore\, n. [Gr. ??? a cord + E. spore.] (Bot.) One of several spores arranged in a chain as in certain alg[ae] of the genus Callithamnion.
Wiktionary
seirospore
n. One of several spores arranged in a chain, as in certain algae.