CONVERGENT SEED-GERMINATION IN SOUTH-AFRICAN FYNBOS AND CALIFORNIAN CHAPARRAL

California chaparral and South African fynbos are fire-prone communiti es dominated by species exhibiting remarkable similarities in germinat ion response. In both regions there are a substantial number of specie s with germination stimulated chemically by charred wood and smoke. Th is type of germination behaviour has arisen independently in distantly related families and is interpreted as convergent evolution. Heat-sho ck is also an important germination trigger that is widespread, althou gh in both regions it is most common in the same families. Phylogeny m ay play an important role in the presence of this postfire germination cue in both regions, but a much more rigorous analysis is required to show that this trait represents a single unique event in each lineage . In both regions, germination response is not randomly distributed ac ross growth forms and there are marked regional similarities in the ty pe of germination behaviour associated with certain growth forms. Geop hytes largely lack refractory seeds, which require fire-type cues for germination, but the presence of fire-stimulated flowering of bulbs an d corms may time recruitment to subsequent postfire years. Annuals tha t cue germination to postfire conditions are predominantly triggered b y chemicals from smoke and/or charred wood.