Named in honor of a pioneer family in central Washington, four generations of whose members have been friends of the discoverer and his family. It honors in particular the memory of Peter Tjossem (1878–1957), millwright, farmer, amateur entomologist, lapidarist, amateur paleobotanist working at a professional level on identification of Miocene fossil woods of central Washington, elder in the Presbyterian Church — and friend to any young person who came to him, in the best traditions of the amateur scientist. (M 10045) _ _.