This study presents a complete taxonomic revision of Anthurium sect. Semaeophyllium, which comprises species with trilobed leaf blades. Leaf lobes are always united at the base in these species, and they can be directed forward (i.e., falcate) or to the sides (i.e., spreading) but never toward the back. Under this circumscription, sect. Semaeophyllium comprises 23 species ranging from southern Nicaragua into Peru. Detailed morphological descriptions, diagnoses, representative photographs, distribution maps, and an identification key are provided.