The Edmund Niles Huyck Preserve is an area of considerable biological interest. It is a privately maintained wildlife preserve of 470 acres, located adjacent to Rensselaerville, Albany Co., New York, on the Helderberg Plateau about 22 miles southwest of Albany. Perhaps its most unusual feature is the maintenance of a small, biological field station, where one or more biologists have carried on field studies annually since 1939. The Preserve was formally established in 1931 in memory of Edmund Niles Huyck, a prominent eastern industrialist, by his widow, Mrs. Jessie V. A. Huyck, and friends. Since the establishment of the summer research fellowships in 1939, the results of many field studies, principally zoological, have been published by the annual research fellows. The Preserve is centered about two bodies of water, both formed by the damiing of Ten-Mile Creek. The smaller is Lincoln Pond, the larger Lake Myosotis. There is little or no level land; slopes vary from moderate to very steep in the locally famous Rensselaerville Gorge. The elevation varies from 1400 ft. to slightly more than 1700 ft. above sea level; nearby hills, not in the Preserve itself, range up to 2200 ft. Slopes facing in all directions are found and support varying vegetation types. Though the area has been protected from disturbance since about 1900, there remain a number of old fields, one of which is still cut for hay each year. The forests vary from mature hemlock-beech to many types of younger deciduous communities. Along the margins of Lincoln Pond and Lake Myosotis wet meadows, alder thickets, and even partly boggy areas are found. In addition, there is a small flora of freshwater strand plants, particularly along the shores of Lake Myosotis, where a shingle beach perhaps 20 ft. wide is annually exposed due to late summer droughts. The vegetation types have been described in other papers (Odum, 1943; Russell, 1955a, 1955b). Because of the very diverse flora and the continued use of this area by field biologists, the need for a checklist of the flora and a herbarium for reference is very great. Some work on these has been done by a number of previous biologists, but, for the most part, it was incidental to zoological studies. Dr. Eugene P. Odum, in connection with his studies of the plant communities of the Preserve in 1939, 1940, and 1941, made a number of collections, but these apparently have been lost. In Dr. Odum's report on the vegetation (1943) he listed many species of vascular plants. Dr. W. J. Hamilton, Jr., the director of research on the Preserve, made the original survey of the Preserve in 1937 and in his typewritten report, on file in the Rensselaerville library, lists a number of vascular plants. The list of species that follows has been prepared entirely from the collections of three investigators, Francis Harper (and his wife Jean Harper),