Austrian plant ecologist and expert in Venezuelan lichens and ferns. Vareschi trained at the University of Innsbruck and gained his PhD (1930) under the supervision of Helmut Gams and his thesis was on the vegetation of the upper Isar Valley. He was employed as an assistant at the Forschungsinstitut R⟼bel in Z⟼rich (1931-1935). He later submitted a thesis on the palynological investigation of glacier movements to Munich University (1935) and was later at the Sven-Hedin-Institut in Lannach bei Graz (1942-1945) before returning to the University of Innsbruck as a lecturer (1947-1949). Vareschi first travelled to Venezuela in 1950 to re-create part of Humboldt's travels, and would return later to become a professor of botany at the Central University of Venezuela (Caracas). His fields of investigation included the ecology of tropical vegetation and the taxonomy of Venezuelan lichens and ferns. Amongst the first to investigate the idea of 'lichen deserts' around big cities, Vareschi studied the effect for both Z⟼rich and Caracas. In July 1967 he landed in the savannah of Simarawochi in a small aeroplane and made the first ecological studies of vegetation and flora in the Sierra Parima. On an expedition to Auyan Tepui, the mountain of Angel Falls, Vareschi identified 61 orchid species in a five-acre area of which several were new to science. He also undertook the first experiments and measurements in ecology and ecophysiology at the Biological Station of Los Llanos, near Calabozo. Vareschi remained in Venezuela until his death in 1991.