In 1993 The Jepson Manual estimated that California was home to 4,693 native species and 1,169 native subspecies or varieties, including 1,416 endemic species. A 2001 study by the California Native Plant Society estimated 6,300 native plants. These estimates continue to change over time.Of California's total plant population, 2,153 species, subspecies, and varieties are endemic and native to California alone, according to the 1993 Jepson Manual study.This botanical diversity stems not only from the size of the state, but also its diverse topographies, climates, and soils (e.g. serpentine outcrops).f California's total plant population, 2,153 species, subspecies, and varieties are endemic and native to California alone, according to the 1993 Jepson Manual study. This botanical diversity stems not only from the size of the state, but also its diverse topographies, climates, and soils (e.g. serpentine outcrops).