In 1867 Schwendener announced to the scientific world his hypothesis that lichen was formed by two separate organisms, a fungus and an alga. At the time his theory was largely rejected, but it was afterwards proven to be factual.
https://github.com/davepinch/pinchy.cc/blob/master/content/topics/people/s/simon-schwendener/simon-schwendener.md
Simon Schwendener (Wikipedia) Simon Schwendener (10 February 1829 – 27 May 1919) was a Swiss botanist who was a native of Buchs in the Canton of St. Gallen.