XVI International Botanical Congess

J. W. Dawson (1857&1859) interpreted Prototaxites as decayed conifer wood with affinity to Taxus(Yew). W.Carruthers (1872) renamed the genus, a marine alga, Nematophycus (Chlorophyta) comparable in size to Lessonia (Phaeophyta). Dawson (1888) disclaiming his earlier classification proposed Nematophyton. Penhallow (1889) retained it in the Phaeophyta. Carruthers refused comparison with the fungi. Church (1919) remarked that affinity with the fungi was credible. Dawson noted on sketches:Like mycelium of fungus. Years' of study indicate that Prototaxites may be defined as a huge fungal fruiting body with a trimitic hyphal system (as in woody basidiomycetes), amphigenous hymenium,and perennial growth from an extensive saprobic, terrestrial mycelium. It is proposed that its extinction resulted from arthropod predation. The genus is known widely geographically and only from Devonian sediments.