The Herbarium of the Department of Biology, University of Puerto Rico - Río Piedras campus (UPRRP) was founded in 1966 by plant ecologist Michael Byer.  At that time we had some bryophyte and freshwater algal specimens stored with the zoological collections, but Mike was the first one to develop a collection of vascular plants and accession them, giving some sense of an ordered collection.

The Herbarium did not begin its growth spurt until the arrival of James Ackerman in 1981. His interest in orchids prompted him to collect this group throughout Puerto Rico and later across the Greater Antilles; his teaching duties in taxonomy spurred his students to do more general collecting. In 1985 he encouraged Franklin Axelrod to begin collecting plants and that began his long and fruitful association with the herbarium; being the latest contribution "A Systematic Vademecum to the Vascular Plants of Puerto Rico" (available from BRIT Press, Amazon and other booksellers). Also at that time, Charlotte Taylor, now at the Missouri Botanical Garden, joined the Department of Biology and collected extensively around the island.  When Charlotte left, Linda Escobar was with us all too briefly and added not only Puerto Rican plants to our collection but also brought some of her Passiflora collection from Colombia.  Due primarily to the efforts of the above collectors and their students, and exchange programs with other herbaria, the collection now contains over 56,000 specimens.