The Biota of the Gordon Natural Area - Plants

Vascular Plants at the GNA

Plant life at the GNA has long held an attraction for both faculty (beginning with Dr. Gordon) and students. Dr. William Overlease conducted extensive research in the GNA, with much of his work focused on the vegetative succession of a former corn field in what is now the western part of the preserve. There have been three site-wide floristic surveys of the GNA: during 1984 (by biology students Jack Holt and Jim Plyler); during 2007 by botanical consultants Jack Holt (the former student) and Janet Ebert; and during 2017-19 in a ‘follow-up’ survey by Jack Holt and Janet Ebert. In 2002, former GNA Stewardship Manager Gerry Hertel began establishing what would become 22 ‘Floristic Health Management’ (FHM) plots. While these were primarily monitored only for woody plants, in 2004 the 18 plots that had been established by that time were also surveyed for herbaceous species. And throughout the history of the GNA there have been many student projects that focused on portions of the GNA flora. Because of this intensity of effort, vascular plants constitute the best-known biotic group at the GNA.

Despite the Gordon’s relatively small size (~ 126 acres) and its proximity to extensive development, the preserve supports an extremely high diversity of native plants (in addition to a large component of introduced plant species). The compiled plant list for the site currently contains 663 species in 364 genera, 110 families, and 56 orders. Five species are on the Pennsylvania Natural Heritage Program's list of species of conservation concern, and many additional species are locally significant.

It should be noted that these 663 species represent all vascular plant species that have been noted at the Gordon Natural Area since the inception of data collecting. Some species have only been observed a single time, and in some cases, the last observation occurred many years ago. For example, New Jersey Tea (Ceanothus americanus), which was formerly a state-listed species, was last noted in the GNA in 1978.

Perhaps a better measure of the GNA’s vascular plant richness can be obtained by looking only at those species that have been noted since the beginning of 2004 (i.e., at the initiation of comprehensive monitoring in the FHM plots). During that period (i.e., 2004-present), 606 species of vascular plants were noted in the GNA.

You can explore the vascular plant checklist below, or you can access a pdf copy of the checklist.