Pistillate papaya flower: a morphological anomaly.
The pistillate flower of Carica papaya is a pleurogynous unisexual form derived intraspecifically from a perigynous bisexual ancestor. It is a morphological anomaly in that the ovary consists of two cycles of carpels which, in the ancestor, arise on the receptacle at different levels as dissimilar orders of organs. The bulk of the pentamerous ovary and the dorsal carpellary vascular system are derived from a cycle of five stamens in the ancestor. The ventral carpellary system is inherited intact from the ancestor which has normal morphology in the sense that the carpels consist of a single cycle of sporophylls.
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W B
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