The Distribution and Taxonomy of Three Western Junipers

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Abstract
On the basis of com-parative morphology, the specific recognition of Juniperus californica and J. osteosperma is continued, and the recognition of 2 geographic races within J. occidentalis as newsspp. is proposed. The shrubby, dioecious J. californica ranges from central Baja California, and the peninsular and coast ranges of California, across the southern Mojave Desert to western Arizona. The Arizona populations represent at 100-mile eastward extension of the reported range. J. osteosperma, characterized by monoecious, arborescent shrubs, occurs in the Great Basin region from southeast Idaho, the southern edge of Carbon County, Montana and central Wyoming to western New Mexico, central Arizona and the mountains of California''s Mojave Desert. Southern California populations at the southwest edge of the Mojave Desert represent an extension of the-reported range of about 75 miles. Juniperus occidenta-lis sip. australiss characterized by large, red barked, dioecious trees, occurs in the Sierra Nevada south of Susanville, California and in the San Bernardino Mountains of Southern California. This study also verifies its occurrence in the San Gabriel, Panamint and Inyo Mountains, and reports a relict occurrence in the White Mountains. The smaller, brown barked, submonoecious J. occidentalis ssp. occidentalis ranges from Susanville, California northward to western Idaho and southeast Washington. The present distribution is related to probably past distribution and some possible evolutionary relationships are discussed.