Dr. Eugene Allen Smith initiated the Mohr Herbarium in the late 19th century when he was State Geologist. The oldest specimens in the collection date to 1840, specimens collected by S.B. Buckley.

Dr. Smith contracted with Mr. Charles Mohr, a Mobile pharmacist, who had amassed a fairly large collection of plants from the Mobile area. The contract was for Mr. Mohr to prepare a Flora of Alabama. Mr. Mohr collected throughout the State, placing collections in the “normal herbarium,” the name by which Mohr referred to the herbarium. This herbarium formed the basis for “Plant Life of Alabama,” which was published in 1901.

About 4500 specimens were deposited in the herbarium prior to the publishing of “Plant Life”. Following Mohr’s death, the Museum staff named the herbarium in his honor.

Dr. Ralph Chermock, Professor of Biology, founded the University of Alabama Herbarium in the 1950’s. Dr. Chermock and his wife added several thousand specimens to a few thousand that had been collected by Dr. Roland Harper, a University professor in the first half of the 20th century. The collection began to grow in the late 1950’s when Dr. Joab Thomas came to the University and assumed curatorship of the herbarium. Dr. Thomas and his students concentrated on Mobile County, Bankhead National Forest, and the Blackbelt Region of Alabama. During this time, the Mohr Herbarium was placed on permanent loan to the University Herbarium.

The collection grew to about 30,000 specimens during Dr. Thomas’ tenure and stayed at that size until Dr. Robert Haynes, the former curator, came to the University in 1976. Since then, the herbarium has approximately doubled in size. The Mohr Herbarium was kept separate at the time Dr. Haynes arrived. It has since been incorporated into the main collection, and all sheets have been remounted onto permanent paper. Previously, the Mohr Herbarium had a different acronym, ALU. All specimens are now to be cited as UNA.