Galls on Flower and Fruit

Abstract

Although flowers are highly specialized organs of plants, flower galls are on the whole relatively simple structures. Structurally and ecologically, they show some affinity to galls on vegetative buds (Chapter VI), but do not surpass them in complexity of structure and development. Inspite of this relative simplicity and low incidence, flower galls exhibit certain ecologic specializations, not found among galls on other organs. The morphogenesis of flower galls is in general more or less complicated by the morphogenetic patterns of the individual floral parts and often embraces an abnormal accentuation of these normal patterns. Though flower galls are caused by Fungi, Nematodes, Acarina, Thysanoptera, Heteroptera, Psyllidae, Aphidae, Brachyscelidae, Coleoptera, Cynipidae and Itonididae, the communities associated with these galls are perhaps the smallest of plant gall communities in general. The number of inquilines, parasites and other ecologic groups is exceptionally small in flower galls. As most flower galls are typically deciduous, successori (vide Chapter XI) may be said to be practically non-existent. Some of the other peculiarities of galls on flowers are related to the restricted seasonal appearance of flowers and the short duration of their development.