Belgian Journal of Botany vol:130 issue:1 pages:59-67
It is demonstrated that an increase in carpel numbers originated from an original bicarpellate condition in the Capparaceae. Possible directions of evolution of carpel numbers are discussed in the light of earlier hypotheses. A comparison of different carpel numbers in the family is suggestive of a progressive increase by partitioning of the placentas and/or the addition of primordia within a single whorl. Evidence is found in the pairwise closing of the four locules in the tetracarpellate Capparis micracantha. Another possibility, found in C. spinosa, is an unordered increase of carpels within a whorl, concomitant with a secondary stamen increase. Comparable processes are probably responsible for higher carpel numbers in the Papaveraceae and Brassicaceae. Two types of false septa are recognized and defined, viz. placental and laminal.