According to our database and The Catologue of Life, Philodendron selloum is a synonym for
Tree Philodendron (Thaumatophyllum bipinnatifidum)
From the CoL page:
Philodendron selloum K.Koch - Species synonym for Philodendron bipinnatifidum Schott ex Endl.
Philodendron selloum var. lundii (Warm.) Engl.- Infraspecific taxon - synonym for Philodendron lundii Warm.