Professor Fred Olday (L) and student Chitra Shanmuga (R) during a lichen collecting trip. Professor Fred Olday (L) and student Chitra Shanmuga (R) during a lichen collecting trip.Most of these specimens—dried vascular plants, lichens, mosses, liverworts, mushroom fungi, and marine algae—are from coastal Maine, but our collection also includes plants from elsewhere in the United States and Canada.

The herbarium’s major collections include the Plants of Acadia National Park  and the Plants of Coastal Maine — the latter collection was compiled by the noted naturalist Dr. William H. Drury, Jr., one of COA’s earliest faculty members.

The herbarium is also a repository for botanical specimens from senior projects and other student research at College of the Atlantic.

Group Number of Specimens
Vascular Plants 11,354
Algae 708
Liverworts (Marchantiophyta) 186
Lichens 1,468
Mosses (Bryophyta) 1,332
Non-lichenized Fungi 691

In addition, the herbarium has a large collection of plant specimens and original botanical notebooks from Dr. Craig Greene, COA’s botany professor from 1980-2003. Greene’s records were instrumental to the production of The Plants of Acadia National Park , a popular guide to the flora of Mount Desert Island, the Schoodic Peninsula, and Isle au Haut.


The herbarium is a cooperative project of College of the Atlantic and Acadia National Park and serves as an important resource for both institutions. Its collections record the past and present flora of Mount Desert Island and surrounding areas, allowing botanists to observe differences in species with respect to time and geography. The dried specimens are used to identify unknown samples by macroscopic and microscopic comparison, for which the herbarium has a selection of microscopy equipment. The herbarium also has a small but comprehensive library of books and periodicals about botany in New England.

Several COA classes utilize the herbarium, including:


Geneva Langley (COA ’94), who is also in charge of the Wild Gardens of Acadia , serves as the herbarium curator. Suzanne Morse is the herbarium director.

Their work is supported by work-study students who have taken botany classes. This team of curatorial assistants includes Hilary  Rose Dawson , Maya McDonald, and Rosemary Santoro. Community volunteers assist with curatorial tasks as well.

Current projects

Herbarium staff are working to digitize the vascular plant collection, as part of a nationwide effort to photograph herbarium collections.



HCOA houses voucher specimens for the following publications written by COA students, alumni, and faculty:

  • Stern, M., I. D. Medeiros, L. Negoita, and N. Rajakaruna. 2016. Limestone flora of the Simonton Corner Quarry Preserve, Rockport, Maine, USA. Rhodora 118: 206-226. (PDF )
  • Negoita, L., M. Dickinson, G. H. Mittelhauser, and N. Rajakaruna. A Comparative Study of the Flora and Soils of Great Duck and Little Duck Islands, Maine, USA. Rhodora 118: 46-85. (PDF )
  • Medeiros, I. D., A. M. Fryday, and N. Rajakaruna. 2014. Additional lichen records and mineralogical data from metal-contaminated sites in Maine. Rhodora 116: 323–347. (PDF )
  • Mansfield, M., N. Pope, G. Mittlehauser, and N. Rajakaruna. 2014. Diversity and Soil-Tissue Elemental Relations of Vascular Plants of Callahan Mine, Brooksville, Maine, USA. Rhodora 116: 283–322. (PDF )
  • Barton, J., B. Ciccotelli, J. E. Gall, F. C. Olday, B. Connery, T. B. Harris, A. M. Fryday, and N. Rajakaruna. 2014. Lichens of six vernal pools in Acadia National Park, ME, USA. Evansia 31: 31–39. (PDF )
  • Rajakaruna, N., T. B. Harris, S. Clayden, A. Dibble, and F. S. Olday. 2011. Lichens of Callahan Mine, a copper and zinc-enriched Superfund site in Brooksville, Maine, USA. Rhodora 113: 1–31. (PDF )
  • Ciccotelli, B., T. B. Harris, B. Connery, and N. Rajakaruna. 2011. A preliminary study of the vegetation of vernal pools of Acadia National Park, Mount Desert Island, Maine, USA. Rhodora 113: 260–279. (PDF )
  • Pope, N., Harris, T. B., and N. Rajakaruna. 2010. Vascular plants of adjacent serpentine and granite outcrops on the Deer Isles, Maine, USA. Rhodora 112: 105–141. (PDF )
  • Rajakaruna, N., N. Pope, J. Perez-Orozco, and T. B. Harris. 2009. Ornithocoprophilous plants of Mount Desert Rock, a remote bird-nesting island in the Gulf of Maine, USA. Rhodora 111: 417–448. (PDF )
  • Briscoe, L. R. E., T. B. Harris, E. Dannenberg, W. Broussard, F. C. Olday, and N. Rajakaruna. 2009. Bryophytes of adjacent serpentine and granite outcrops on the Deer Isles, Maine, USA. Rhodora 111: 1–20. (PDF )
  • Harris, T. B., F. C. Olday, and N. Rajakaruna. 2007. Lichens of Pine Hill, a periodotite outcrop in eastern North America. Rhodora 109: 430–447. (PDF )
  • Greene, C. W., L. L. Gregory, G. H. Mittelhauser, S. C. Rooney, and J. E. Weber. 2005. Vascular flora of the Acadia National Park region, Maine. Rhodora 107: 117–185.
  • Greene, C. W. 1987. Calamagrostis pickeringii in Maine. Rhodora 89: 333–336.

Additionally, HCOA specimens have been examined by outside researchers for various papers, including those listed below:

  • Haines, A. 2004. Draba glabella (Brassicaceae), new to Maine. Rhodora 106: 55–59. (PDF )
  • Brunton, D. F. and D. M. Britton. 1993. Isoetes prototypus (Isoetaceae) in the United States. Rhodora 95: 122–128. (PDF )