Trochodendron nastae is an extinct species of flowering plant in the family Trochodendraceae known from fossil leaves found in the early Eocene Ypresian stage Klondike Mountain Formation deposits of northern Washington state.

T. nastae is one of the oldest members of the genus Trochodendron, which includes the living species T. aralioides, native to Japan, southern Korea and Taiwan[1] and the coeval extinct species T. drachukii from the McAbee Fossil Beds near Cache Creek, British Columbia.

[2] Description of the new species by Dr. Kathleen B. Pigg, Wesley Wehr, and Stefanie Ickert-Bond was based on the study of 11 complete and 55 partial compression fossil specimens with the holotype specimen, number "SR 98-02-01", being housed in the Stonerose Interpretive Center, Republic, Washington.

[1] Trochodendron shares with Tetracentron the very unusual feature in angiosperms, of lacking vessel elements in its wood.

This has long been considered a very primitive character, resulting in the classification of these two genera in a basal position in the angiosperms; however, genetic research by the Angiosperm Phylogeny Group has shown it to be in a less basal position (early in the eudicots), suggesting that the absence of vessel elements is a secondarily evolved character, not a primitive one.