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Query the Plummers Island Checklist

About Plummers Island
Plummers Island is a small (12-acre) wooded island (see Map) in the Potomac River in Montgomery County, Maryland, just downriver from the American Legion (Cabin John) Bridge between Maryland and Virginia for the Beltway (Interstate 495). It is separated from the Maryland shore by only a narrow channel and is nine shore miles northwest (upriver) of the White House. It lies between Locks 10 and 12 of the C&O Canal. The island was purchased by the Washington Biologists’ Field Club in 1908, along with 35 acres of the mainland between it and the canal, to which was added 3.5 acres in 1924, for a total of 38.5 acres of mainland. Ownership of the island andmainland acreage passed to the National Park Service in 1961 with an agreement that the Club could continue indefinitely to do research on the island and adjacent mainland and to maintain and use the cabin it had built on the island for club functions. Fern Rock  and Plummers Island Cabin (photos taken 1906)
The island has a high rocky center, where the cabin is built, which drops down in varying degrees of steepness to floodplain on the east and south sides. This topographic relief, with floodplain and rocky outcrops, has given rise to habitat diversity despite the small size of the island. Major floods have scoured the lower parts repeatedly over the years and in the process renewed the flora, which accounts in significant measure for the relatively large flora that has been recorded for the island. "Present Plant Communities on Plummers Island" by Elizabeth F. Wells describes the three main types of plant communities: riparian, terrace, and upland forest.

About the Checklist
Plummers Island creek (photo taken 1906)From the outset, the Club has encouraged and sponsored research on the natural history of the island and adjacent mainland. A long series of scientific papers and books, "Natural History of Plummers Island, Maryland" (see the 1935 "Flowering Plants and Ferns"), has been published to date in the Proceedings of the Biological Society of Washington. The present Checklist of the Vascular Plants of Plummers Island, Montgomery County, Maryland is published in the Bulletin of the Biological Society of Washington, No. 14 (2006), pp. 1 - 58. For a draft of the Checklist, click here for full document** [updated August 2005], and here for brief explanation of how to use the Checklist. The Checklist, by Stanwyn G. Shetler, Sylvia Stone Orli, Elizabeth F. Wells and Marcie Beyersdorfer, includes all the vascular plants of the flora--the ferns, fern allies, gymnosperms, flowering plants--that have ever been reported growing in the wild on Plummers Island and the Mainland. Previous publications on the vascular plants were:

E.P. Killip & S.F. Blake (photos taken ca. 1924)
  • Flowering plants and ferns, by E. P. Killip and S. F. Blake. Proc. Biol. Soc. Wash. 48: 118-134. 1935.
  • Flowering plants and ferns–Supplement 1, by E. P. Killip and S. F. Blake. Proc. Biol. Soc. Wash. 66: 31-38. 1953.

Phlox (photo taken 1919)The total number of species in this Checklist is 885, as compared to the previous total of 846. Of these, 75 have been found only on the Mainland, and 704 are native, 181 naturalized. One of the 885 species, bloodleaf (Iresine rhizomatosa), was first discovered by science on the island, but unfortunately this species has since disappeared from the island.

Cactus with geranium (photo taken 1919)The Checklist is based on the Plummers Island Herbarium, maintained as a separate part of the DC Herbarium. For each species, the number of specimens in the herbarium is given in parentheses after the common name(s) and the most recent voucher specimen on file is cited; otherwise, the source of information is cited. An asterisk (*) denotes a species found only on the Mainland, and a plus (+) denotes a species that is new to the flora since the earlier lists.

**You must have Adobe Acrobat Reader to read this file.

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