Carpel morphology and axis-sharing in syncarpy in some Rutaceae, with further comments on “New Morphology”

Abstract

Carpels in Choisya, Rufa, Poncirus and Citrus are peltate. In Citrus the style contains as many isolated canals as there are carpels, and these canals are shown to be bounded by the morphologically outer (lower) surface of the carpel. All instances exhibit an at least incipient syncarpy, and the floral axis is always involved in the central merging of the carpels. This is especially obvious here on account of vascular anatomy. Both peculiarities are probably much more widespread than is generally allowed; some other examples are afforded. The axis of the flower is certainly the same as that of the vegetative portion of the plant, and Meeuse's concept of a pseudo-axis in the flower cannot apply here.