Lauria, F. 1996. The identity of Pinus ponderosa Douglas ex C Lawson (Pinaceae). Linzer Biologische Beitraege 28(2): 999-1052.

ABSTRACT: Pinus ponderosa s.l. is a commercially important and polymorphic conifer. its taxonomy (and that of its entire group, the 'ponderosa complex') is far from being settled (Kral 1993). This unsettled status is largely due to absence of a type, a circumstance which also accounts for the fact that even the very identity of Pinus ponderosa s.str. itself is notoriously confused. The earliest sources documenting the intricacies of the discovery and late publication of ponderosa pine as a new species in 1836 are reviewed. Detailed study of its earliest botanical history is demonstrated to be essential to finally establish its original identity, as meant by David Douglas and described by Charles Lawson. Pinus ponderosa Douglas ex C. Lawson is then neotypified with authentic material (an ovuliferous cone) discovered in a historical collection of conifer cones surviving at the Natural History Museum in Vienna, Austria (W). The extensive synonymy pertaining to the 'ponderosa complex' is reviewed (including typification of several of these synonyms) and some new facets of the life and achievements of David Douglas, who is commonly credited with the discovery of Pinus ponderosa, are also reported here for the first time.