spermatium
noun
sper·ma·ti·um (ˌ)spər-ˈmā-sh(ē-)əm 
plural spermatia (ˌ)spər-ˈmā-sh(ē-)ə
: a nonmotile male gamete of a red alga
also : a nonmotile cell functioning as a male gamete in certain fungi and lichens
spermatial
(ˌ)spər-ˈmā-sh(ē-)əl
adjective 
Word History
Etymology
New Latin, from Greek spermation, diminutive of spermat-, sperma
First Known Use
1856, in the meaning defined above