Hannibal Woods is a small, oak-ash (Quercus macrocarpa/ Fraxinus pensylvanica) forest relict located on the south and west sides of Dannebrog, Nebraska. The site was first studied in 1996 as part of a botanical survey of the Loup River Valley. Since the initial work, plant collections have been made several times each growing season through 2005, and an annotated list of plant species has been compiled. This study reports a total of 271 plant species representing 62 families including 86 species that are new records for Howard County. The mature bur oaks at this site average 84.0 cm in diameter. Species that are uncommon in central Nebraska include Agastache nepetoides, Arabis hirsuta var. pycnocarpa, Botrychium virginicum, Bromus ciliatus, Bromus latiglumis, Carex grisea, Carex leavenworthii, Carex molesta, Elymus villosus, and Ulmus rubra. Hannibal Woods is botanically significant in that it supports the growth of plant species which are more representative of sites further east, such as the lower Platte and Missouri River Valleys
