spermatangium

[ spur-muh-tan-jee-uh m ]
/ ˌspɜr məˈtæn dʒi əm /

noun, plural sper·ma·tan·gi·a [spur-muh-tan-jee-uh] /ˌspɜr məˈtæn dʒi ə/.

the organ that produces spermatia in red algae.