Typification of Sydneia manleyi Pšenička et al. 2003 is based entirely on fertile foliage. Of late, attached sterile-fertile segments have been found which are illustrated and described, together with cutic-ular preparations. A new subfamily, Sydneideae subfam. nov. is erected for the monotypytic species. The synangial chemistry is compared with marattialean synangia/sporangia from the Czech Republic and from Canada.