Two new spontaneous hybrids of American hard pines from Pinus sect. Trifoliae (Pinaceae) found in the unique Russian Sochi Arboretum.

摘要

In the 1990s, an extraordinarily abundant live collection of the genus Pinus, including 49 species, 4 subspecies, and 7 interspecific hybrids, found in the Sochi Arboretum in Russia on the northeast coast of the Black Sea, was taxonomically revised. Among these taxa, two previously unknown interspecific hybrids of American hard pine species from P. sect. Trifoliae had arisen spontaneously in culture. These are described here as the new hybrid species Pinus x transamericana (P. muricata x P. rigida) and Pinus x critchfieldii (P. patula x P. taeda). All known natural or artificial interspecific hybrids within P. sect. Trifoliae are listed, and hybridization between American hard pine species is discussed.