The genus Fritillaria contains about 100 spp. in Europe, N. Africa, temp. Asia, and western N. America. It is divided into a number of fairly well-characterized sections. There is, however, frequent breakdown in character correlations giving "reticulation" of characters. Examples of this for characters of bulbs, leaves, petals, stamens, and capsules are given for spp. in different sections of Fritillaria and for other genera of the Tulipeae. The history of the "reticulation" concept is briefly outlined and it is shown that true and false reticulations have to be distinguished, It is probable that an extensive and intensive study of "reticulation," defined as the occurrence in different combinations of characters described in the same or similar terms, would throw much light upon general problems of evolution. Suggestions are made as to the probable underlying causes of reticulation.