Most california sages also require the presence of ashes to germinate. It's quite common amongst flora in the California chaparral. In large part due to thousands of years of ecosystem management with controlled burns by native Californians. In a lot of ways California is a manufactured landscape (though even Amazonia has been labelled as manufactured[0] so it's not all that surprising)

[0] https://www.researchgate.net/publication/259126195_Dark_eart...