The Geography of Phytochemical Races

90 2 Examples Within Continents
Fig. 2.55 Diagram of
Lasthenia californica
transect study
using potting soil showed that achenes from race A plants always yielded race A
progeny, and that achenes from race C plants afforded mostly race C plants with an
occasional race B individual. These observations suggested that the fl avonoid profi
les of L. californica are genetically controlled, and do not require serpentine soil
for fl owering or fl avonoid production.
Figure 2.56 illustrates the results of an expansion of the fl avonoid survey to the
entire range of the species. Populations having either totally or predominantly the
Fig. 2.56 Map of Lasthenia californica populations sampled for fl avonoid variation study