-_əm noun
Usage: capitalized
Etymology: New Latin, alteration of Latin asplenum spleenwort, from Greek asplēnon, irregular from splēn spleen — more at spleen
: a widely distributed genus of ferns (family Polypodiaceae) having linear or oblong sori borne obliquely on the upper side of a veinlet and comprising the spleenworts — see ebony spleenwort , wall rue