BOYD, STEVE. Herbarium, Rancho Santa Ana Botanic Garden, Claremont, CA 91711. - Vascular flora of the Liebre Mountains, Western Transverse Ranges, California.
The Transverse Ranges, with their east-west orientation, are one of
southern California's most prominent physiographic features, and
contain large tracts of intact, biologically diverse, public trust
lands. Areas such as these are critical for meeting societal goals of
preserving California's natural heritage, but long-term conservation
requires development of a baseline account of the resources being
managed. Although much of the Transverse Ranges border the Los
Angeles Basin, California's most densely populated region, published
floristic accounts of the component ranges are surprisingly scarce.
This study represents a preliminary floristic account of the Liebre
Mountains region, and includes the results fieldwork conducted over a
nine year period (1990-1999), as well as review of collections housed
in the herbarium of Rancho Santa Ana Botanic Garden (RSA-POM) and
elsewhere. The Liebre Mountains form a discrete unit within the
western portion of the Transverse Ranges, and are geographically and
floristically transitional to the San Gabriel Mountains, Inner Coast
Ranges, Tehachapi Mountains, and Mojave Desert. A total of 1,010
vascular plant taxa was recorded from the range, representing 104
families and 400 genera. The ratio of native vs. nonnative elements
of the flora is 4:1, similar to that documented in other areas of
cismontane southern California. The range is noteworthy for the
diversity of Quercus taxa and associated oak-dominated
vegetation, and represents the southern limit of the foothill woodland
flora characteristic of ranges bordering California's Central Valley.
A total of 32 sensitive plant taxa (rare, threatened or endangered)
was recorded from the range.
Key words: flora, Liebre Mountains, sensitive plants, southern California, Transverse Ranges