He studied medicine in Berlin and Munich, and afterwards, trained as a pharmacist in Karlsruhe.
From 1876, he worked as a curator in the herbarium of botanist Émile Burnat (1828–1920) in Nant, located near the town of Vevey.
Gremli published several works on Swiss flora, including Excursionsflora für die Schweiz (1867), a book that was later translated into English.
In addition, he collaborated with Burnat on a number of essays involving flora from the Maritime Alps.
This article about a Swiss botanist is a stub.