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Abstract
The pines have been more successful than most of their coniferous relatives in occupying marginal habitats at the upper and lower edges of the forest zone in western North America. Among the groups restricted to such habitats is subsection
Baljourianae of
Pinus, comprising the fox tail and bristlecone pines. These pines characteristically grow on cold dry sites at high elevations, and in most places have few tree associates. Perhaps because of their inaccessibility and limited economic importance, not much was known about them until E. Schulman's discovery in the mid-1950's that some bristlecone pines reach greater ages than other higher organisms (Ferguson, 1968). Since then, much has been learned about the
Baljourianae, and investigations of natural variation have generated two taxonomic proposals in the group. Bailey (1970) named the western populations of bristlecone pine
P. longaeva, restricting the older name,
P. aristata Engelm., to the eastern populations. Mastrogiuseppe (1972) proposed the subdivision of foxtail pine (
P. balfouriana Grev. & Balf.) into two subspecies.
Citation
Critchfield, William B. 1977. Hybridization of foxtail and bristlecone pines. Madroño, Volume 24(4): p. 193-212