The occurrence of Cunninghamia chaneyi from the middle Miocene sediments of the former Lake Clarkia in Northern Idaho is the last known occurrence of this genus in the geologic record of North America. Cunninghamia chaneyi has been reported on the basis of foliar branches from the Oligocene Rujada, Lyons and Bridgecreek floras of Oregon and the Oligocene Gumboot flora of southwestern Washington. These resemble the extant C. lanceolata. The C. marquettii from the Haynes Creek flora of east central Idaho more closely resembles C. konishii. Both C. protokonishii from the middle Miocene of Japan and C. europaea from the later Miocene of Poland also resemble C. konishii. The C. miocenica that has been described from the Oligocene and Miocene of central Europe is thought to be intermediate between the two extant species. The Clarkia Cunninghamia chaneyi is represented at four localities by well preserved compressions and impressions of foliar branches, rarely single needles, seed cones and pollen cone fascicles. The foliar branches are similar to those found beneath arboretum trees of C. lanceolata. The needles are slightly smaller in both width and length than those of the extant species. The size of the cones and cone fascicles of the fossils is identical to that of the extant C. lanceolata. However the shape of the cone bracts, the reduced cone scales and the seed attachment scars are some what different from that of the extant species. Most significantly, stomatal bands on the fossil species are half as wide as those on the extant species. The excellent preservation allowed analysis of extractable chemical compounds from foliar branches and cones of Cunninghamia chaneyi from Clarkia. Several mono-, sesqui- and diterpenoids have been identified in the extracts. The sesquiterpenoid pattern is similar to that described from the resin of C. miocenica from Central Europe.

Key words: Cunninghamia chaneyi, fossil, Idaho, Miocene, Taxodiaceae