Academics require good libraries, but many botanists need more than books -- they need actual plants.  The John W. Thieret Herbarium serves that purpose. It is a library of approximately 40,000 pressed and dried plant specimens.

Our Mission:

            To document wild & cultivated flora

            To facilitate floristic research

            To educate students & the public

For these purposes, the herbarium seeks to maintain, provide access to, and augment its collections of these plants. The staff is committed to serving the scientific community and to providing outreach by sharing collections and botanical expertise with those not of that community.

Visitor Information:

The collections are primarily used by researchers, but educational tours for students or interested community groups may also be possible. Contact Dr. Whitson to inquire.

            Location: Room SC 101 in the Dorothy Westerman Herrmann Natural Science Center.

            Hours: by appointment. E-mail Dr. Whitson: whitsonma at nku.edu

            Click here for campus maps and directions. Visitor parking is available in the Kenton Drive Parking Garage.


            Dr. Maggie Whitson
            Office: SC 101B
            Phone: 859-572-1411
            E-mail: whitsonma at nku.edu

Mailing Address:

            The John W. Thieret Herbarium
            Biological Sciences Department, SC 204D
            Northern Kentucky University
            Highland Heights, KY 41076

History and Holdings:

            Founded: 1973

            Herbarium code: KNK
                            (from Index Herbariourum)

            Holdings: 40,000 specimens


                        From 1973-1992: Dr. John Thieret

                        From 1992-2001: Dr. Rob Naczi

                        From 2003 to present: Dr. Maggie Whitson


Our focus is vascular (mostly flowering) plants of the US, particularly from Kentucky, Ohio, and the Southeast. We also have extensive collections from the Great Basin, the Great Plains, and the Canadian Arctic.

Our collections are particularly rich in wetland and aquatic plants and grasses (the Poaceae), which were specialties of Dr. Thieret, and sedges (the Cyperaceae), which were Dr. Naczi's focus.  

Little brown jug.

Little brown jug.

Hexastylis arifolia. Collected in Kentucky, 1993.
Buffalobur nightshade

Buffalobur nightshade

Solanum rostratum. Collected in Kansas, 1998.
Common rue.

Common rue.

Ruta graveolens. Collected in Ohio, 2003.


Tamarix sp. Collected in Utah, 1997.
Poison ivy.

Poison ivy.

Toxicodendron radicans. Collected (cautiously) in Kentucky, 1984.
Cockspur pricklypear.

Cockspur pricklypear.

Opuntia drummondii. Collected in North Carolina, 1989.
Wild cucumber.

Wild cucumber.

Echinocystis lobata. Collected in Minnesota, 1994.
Buffalo gourd.

Buffalo gourd.

Cucurbita foetidissima. Collected in Kansas, 1987.