Botanical survey of Myrtle Island Research Natural Area, Oregon.

Abstract

Myrtle Island Research Natural Area, an 11.3-ha island in the Umpqua River Valley of the Oregon Coast Range, was established in 1951 to preserve an old-growth stand of Umbellularia californica and scattered old-growth Pseudotsuga menziesii. This floristic study documented 363 specific and infraspecific taxa in 237 genera and 78 families. Of these species, 155 (42.7 percent) are naturalized exotics. Seventeen exotic or native species are listed as noxious weeds in Oregon. Vascular plants include 4 Equisetophyta, 8 Polypodiophyta, 2 Pinophyta, and 349 Magnoliophyta; 328 are annual, biennial, and perennial herbs, and 35 are woody vines, shrubs, and trees. The largest families in species richness are the Poaceae (50), Asteraceae (43), Fabaceae (29), Rosaceae (17), Cyperaceae (16), Scrophulariaceae (14), Caryophyllaceae (13), and Brassicaceae (13). This vascular plant survey provides a baseline reference for species richness, plant communities, generalized life forms, and relative abundance within Myrtle Island Research Natural Area.

Citation

Thompson, Ralph L. 2001. Botanical survey of Myrtle Island Research Natural Area, Oregon. Gen. Tech. Rep. PNW-GTR-507. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 27 p