Alfred Ernst (21 February 1875, Winterthur – 17 September 1968, Zürich) was a Swiss botanist.

He attended classes at the teachers' seminar in Küsnacht, followed by studies of biological sciences in Paris. From 1897 to 1899 he worked as a teacher in Naples. Afterwards, he received his doctorate in sciences from the University of Zürich, where in 1905, he became an associate professor. From 1909 to 1945 he was a professor of general botany at Zürich, being chosen university rector in 1928.^[1]

His primary research dealt with the propagation of algae, the embryology of flowering plants and heterostyly in Primula species.^[1] In 1905/06 and 1930/31 he was involved in botanical investigations in Java.^[2]

Selected works

• Bastardierung als Ursache der Apogamie im Pflanzenreich, 1918 – Hybridization as the cause of apogamy in the plant kingdom.
• Ernst, A. (1922), "Artkreuzungen in der Gattung Primula (Species crosses in the genus Primula)", Zeitschrift für induktive Abstammungs- und Vererbungslehre, 27: 233–235
• Ernst, A. (1922), "Chromosomenzahl und Rassenbildung (Chromosome numbers and race formation)", Vierteljahrsschrift der Naturforschenden Gesellschaft in Zürich, 67: 75–108
• Genetische Studien über Heterostylie bei Primula, 1925 – Genetic studies of heterostyly in Primula.
• Weitere Studien über die Vererbung der Calcycanthemie bei Primula, 1931 – Further studies on inheritance of calycanthema with Primula.
• Die Nachkommenschaften aus Kreuzungen zwischen dimorphen und monomorphen Primula-Arten der Sektion Candelabra, 1943 – The progeny from crosses between dimorphic and monomorphic Primula species of the section Candelabra.^[3]