We lose all tropical plants, which are now in Mexico and south.
Some plants could survive or adapt to these changed conditions, if they had the genetic variation to do so. Annuals could shorten their life cycle and shift it to winter. Perennials could slowly change their growing season from summer to spring.
Some of the plants previously widespread here begin to retreat to riparian (Latin ripa, banks of a river) areas, or to higher elevations where there is less moisture stress.
The surviving vegetation from this time is called the Arcto-Tertiary geoflora, or North Temperate Seed Plants. (Arcto: northern areas; Tertiary: the geologic period from 65 million years ago to the start of glaciation 2 million years ago.) These are true long-term California natives!
Examples: all willows, alders, rushes; most asters, ragweed, dodder, ranunculus, owl's clover, Mariposa lilies, telegraph weed, lupines, peony, checkerbloom, goldenrod, poison oak, viola.
Where do these species live at the Santa Rosa Plateau now?
Comments and feedback: Tom Chester
Last update: 6 November 2005.