To Santalaceæ they approach in processes, valvate corolla, and placentation, also to Loranthaceæ.
The placentation is constantly axile in the inferior row and parietal in the upper one.
In double flowers of Primulaceæ similar alterations in the placentation may often be observed.
placentation plac·en·ta·tion (plās'ən-tā'shən)
Formation of a placenta in the uterus.
The type or structure of a placenta.