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Academics require good libraries, but many botanists need more than books - they need actual plants.

The John W. Thieret Herbarium is one of NKU's secret treasures: a library of over 35,000 pressed and dried plant collections. These collections are used for both research and teaching. 

The herbarium is located on the first floor of the Dorothy Westerman Herrmann Science Center, in Room 101. Visitors are welcome, but the hours are irregular, so please call or e-mail first to make sure that the herbarium is open.

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: Dorothy Westerman Herrmann Natural Science Center (SC), Room 101

Hours: By appointment. Contact the Herbarium Director for scheduling.


  • Founded: 1973
  • Herbarium code: KNK (from Index Herbariorum)
  • Holdings: 40,000 specimens

Past and Present Directors:

  • 1973-1992: Dr. John Thieret
  • 1992-2001: Dr. Rob Naczi
  • 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.


Databasing of collections information started in 2007 and is primarily due to the volunteer efforts of multiple students. Specify 6 is our database platform.

To date, 10,000+ records and 3000+ images have been generated. Explore the Southeast Regional Network of Expertise and Collections (SERNEC) website for details. New collections are databased before being filed the first time, and older collections as time allows.

Hexastylis Arifolia specimen

Hexastylis Arifolia

Collected in Kentucky, 1993.

Buffalo Nightshade specimen

Buffalo Nightshade

Collected in Kansas, 1998.
Ruta Graveolens specimens

Ruta Graveolens

Collected in Ohio, 2003.
Tamarix specimen


Collected in Utah, 1997.
Toxicodendron Radicans (Poison Ivy) specimen

Toxicodendron Radicans (Poison Ivy)

Collected (cautiously) in Kentucky, 1984.
Opuntia Drummondii (Cockspur Prickly Pear) specimen

Opuntia Drummondii (Cockspur Prickly Pear)

Collected in North Carolina, 1989.
Echinocystis Lobata (Wild Cucumber) specimen

Echinocystis Lobata (Wild Cucumber)

Collected in Minnesota, 1994.
Cucurbita Foetidissima (Buffalo Gourd) specimen

Cucurbita Foetidissima (Buffalo Gourd)

Collected in Kansas, 1987.


Dr. Maggie Whitson
Office: SC 101B
Phone: (859) 572-1411

Mailing Address:

The John W. Thieret Herbarium
Biological Sciences Department, SC 204D
Northern Kentucky University
Highland Heights, KY 41099