Plant Evolution: introduction. Chloroplast Genetics and Endosymbiosis. Chromosome Doubling Mechanisms. The Evolution of Polyploidy. Summary: Polyploid Evolution. Plant Systematics. Angiosperm Origins and Evolution Plant Reproductive systems The Male Function Hypothesis. Frequencies of Sexual Morphs in Sagittaria latifolia Populations Sex Allocation in Ragweed. Plant Insect Resistance. Programmed Cell Death in Plants. Root Hair Mutants.