Raleigh Ecological Services Field Office
Conserving the Nature of America

Canby’s dropwort (Oxypolis canbyi)

Canby's Dropwort. Credit: Dale Suiter.

Canby’s dropwort. Credit: Dale Suiter.

Family: Carrot (Apiaceae)

Federal Status: Endangered, listed February 25, 1986

Best Search Time: Mid-July through September

Description: Canby’s dropwort is a perennial herb which grows 2.6 - 3.9 feet (0.8 – 1.2 meters) tall. The stems are round in cross section, ascending and stiff. They arise from scaly buds at the tips of the previous year’s rhizomes or the first, second or third nodes. The stems branch well above the mid-stem, with the branches arching-ascending and forking. The quill-like leaves are slender, round, hollow and septate. The flowers consist of compound umbels of small five parted flowers which appear from mid-July through September with white petals and pale green sepals, some of which are tinged with red or pink. The fruit is a schizocarp about 0.16 - 0.24 inch (4 – 6 millimeters) long, broadly obovoid or ellipsoidal and strongly compressed.

Habitat: Canby’s dropwort has been found in a variety of coastal plain habitats, including natural ponds dominated by pond cypress, grass-sedge dominated Carolina bays, wet pine savannas, shallow pineland ponds and cypress-pine swamps or sloughs. The largest and most vigorous populations have been found in open bays or ponds that are wet throughout most of the year but which have little or no canopy cover. Soils are sandy loams or acidic peat mucks underlain by clay layers which, along with the slight gradient of the areas, result in the retention of water.

map of Canby's Dropwort distribution in North Carolina

Map of Canby's Dropwort distribution in North Carolina.

Distribution: Canby's dropwort recently occurred in Delaware, Georgia, Maryland, North Carolina and South Carolina. The single North Carolina population is now considered historic as the species has not been seen at that site in several years.

Threats: The most serious threat to Canby’s dropwort is the loss or degradation of the wetland habitats in which it occurs. Ditching and draining of wetlands has altered the groundwater table in many areas of the mid-Atlantic coastal plain where this species historically occurred. Much of this habitat destruction was completed for agricultural and silvicultural purposes. Highway construction and maintenance/improvement projects are believed to have adversely affected some populations. Herbicides, either directly or indirectly, may have impacted populations that occur on highway rights of way, agricultural fields and pine plantations. Predation by various insects and ineffective seed dispersal may also limit population expansion and colonization.

References:

Buchanan, M.F. and J.T. Finnegan. 2010. Natural Heritage Program List of the Rare Plant Species of North Carolina. NC Natural Heritage Program, Raleigh, NC.

U.S. Fish and Wildlife Service. 1990. Canby’s Dropwort Recovery Plan. Atlanta, Georgia. 25 pp.

For More Information on Canby's Dropwort...

Species Contact:

Dale Suiter, Fish and Wildlife Biologist, 919-856-4520 ext. 18

Species profile revised on August 29, 2011.

Last Updated: November 1, 2012