Crossability and relationships of Washoe pine

Abstract

Washoe pine, related to ponderosa pine but occurring at higher elevations along the western edge of the Great Basin, crosses freely with the Rocky Mountain race of ponderosa despite evidence of long-term separation. Washoe is morphologically distinct from the parapatric Pacific race of ponderosa pine, and the two taxa are kept separate partly by genetic barriers that reduce seed yield by about two-thirds. Washoe pine most closely resembles North Plateau ponderosa pine, and may be a late-Pleistocene offshoot of this race, which occupies the Pacific Northwest interior.

Citation

Critchfield, William B. 1984. Crossability and relationships of Washoe pine. Madroño, Vol. 31, No. 3: p. 144-170