Landolt grew up in the Zürich district
Enge. He was the eldest son of the lawyer, politician and later Zürich's mayor Emil Landolt and the great-grandson of his namesake Elias Landolt, a forest scientist. At
ETH Zurich (ETHZ), Elias Landolt (the younger) studied natural science from 1945 to 1949 and received his doctorate there in 1953 under the professors Ernst Gäumann and Walo Koch with a dissertation on
Ranunculus montanus (mountain buttercup). From 1953 to 1955, he was a postdoc in California, first at the
Carnegie Institution for Science, Department of Plant Biology, Stanford, and then at
Caltech in Pasadena. Returning to Zürich in 1955, Landolt joined the academic staff of ETHZ, where he worked until his retirement. In 1957 he completed his habilitation thesis
Physiologische und ökologische Untersuchungen an Lemnaceen (Physiological and ecological studies on duckweeds). From 1957 to 1964 he worked as a Privatdozent in
systematic botany, especially systematics of flowering plants. In 1964, Landolt was appointed associate professor of systematic botany, in particular
Phanerogamae systematics. He worked from 1966 to 1967 as a professor extraordinarius and from 1967 to 1992 as a professor ordinarius of geobotany; he gave his farewell lecture in February 1993. He also served as director of the Geobotanical Institute from 1966 to 1993, Rübel Foundation (now part of the Institute of Integrative Biology in the Department of Environmental Sciences of ETHZ). Even after his retirement in 1992, Landolt remained active in research. == Research and conservation ==