Dillenius, Johann Jacob (1687–1747)

German botanist, botanical artist, and physician who studied and produced several papers on cryptogams (lower plants that do not have seeds or flowers), such as mosses and algae.

Dillenius was born in Darmstadt, Germany. He studied medicine at Giessen, where his father was the professor of medicine, and graduated 1713. While he was a doctor, he became interested in botany. However, because he was critical of Bachmann's system of classification, he did not succeed in establishing a reputation for himself in Germany.

In 1721, he went to England where he worked with Sherard to produce an encyclopedia. In 1724, he was elected a Fellow of the Royal Society and was awarded an honorary MD by St John's College, Oxford 1734. When world renowned naturalist Carolus Linnaeus, visited Oxford 1736, it was as Dillenius's guest. In 1741, his Historia Muscorum was published.