Fruit Morphogenesis in ‘Basal Ericaceae’

Fruit morphology and anatomy of representatives of all four Ericaceae subfamilies belonging to the ‘basal Ericaceae’ grade (Enkianthoideae, Pyroloideae, Arbutoideae and Monotropoideae) were studied. Four morphogenetic types of fruits were identified: capsule of Hamamelis type (Enkianthus, Pyrola), capsule of Lilium type (Moneses, Monotropa), berry of Nuphar type (Monotropastrum, Arbutus), pyrenarium of Butia type (Arctostaphylos). The integration of the original carpological materials and the data from molecular genetic studies allowed us to determine the ancestral fruit type in Ericaceae s.l. (capsule of Hamamelis type). The main trends of fruit morphogenesis in ‘basal Ericaceae’ are: (1) reduction and loss of the continuous sclerenchymatous zone in the pericarp, (2) loss of the dehiscence mechanism.