The species was described from specimens of
silicified rhizomes and frond bases in blocks of
chert. The cherts were recovered from sediments outcropping near the contact of the
Roza Basalts and the overlying
Priest Rapids Basalts, designated the
type locality, near the town of
Beverly, Washington by Fred Brinkman of
Sunnyside, Washington. Further specimens of
O. wehrii have been found at the "Ho ho" site, one of the "county line hole" fossil localities north of
Interstate 82 in
Yakima County, Washington. The "Ho ho" site works strata which is part of the Museum Flow Package within the interbeds of the Sentinel Bluffs Unit of the central Columbia Plateau N2
Grande Ronde Basalt,
Columbia River Basalt Group. The Museum Flow Package interbeds are dated to the
middle Miocene and are approximately 15.6 million years old. The
holotype specimens, two pieces of the same chert specimen containing rhizomes and frond bases, are preserved in the
Burke Museum of Natural History and Culture as specimen numbers "
4772" and "
4773". The specimens of chert were studied by
paleobotanists Charles N. Miller jr of
University of Montana. Miller published his 1982
type description for
Osmunda wehrii in the
American Journal of Botany volume 69 article "
Osmunda wehrii, a New Species Based on Petrified Rhizomes from the Miocene of Washington". In his type description he noted the
etymology for the
specific epithet wehrii, in honor of
Wesley C. Wehr who made the type specimens available to Miller for study. ==Description==