Eupatorium leucolepis var. novae-angliae

Common Names:
justiceweed, New England boneset, New England white-bracted thoroughwort, white-bracted boneset
Growth Habit:
CPC Number:
Profile Contributors:
Elizabeth J. Farnsworth
Fully Sponsored

Reference Links

ITIS - Tropicos - USDA Plants - Fish & WildLife

Participating Institutions

The following Participating Institutions are custodians for this species in the CPC National Collection:
New England Wild Flower Society

The conservation of Eupatorium leucolepis var. novae-angliae is fully sponsored.
Elizabeth J. Farnsworth contributed to this Plant Profile.


Eupatorium leucolepis var. novae-angliae is a member of the daisy family (Asteraceae) and endemic to southeastern New England. Only sixteen populations are left in four counties of Massachusetts and Rhode Island. The taxon occurs almost exclusively in coastal plain ponds -- unique habitats in which water levels, fed by groundwater, fluctuate greatly from year to year. Plant population numbers track these fluctuations, with many plants appearing when water levels are low. Eupatorium leucolepis var. novae-angliae is a member of a specialized guild of rare plant species that are restricted to coastal plain ponds where they are not out-competed by other vegetation. Reasons for its increasing rarity include an apparent loss of sexual reproduction due to male sterility in the variety, as well as factors that negatively influence the water quantity and quality of coastal plain ponds (especially development with attendant water withdrawal and diversion). Off-road vehicles, excessive public use of pond beaches, and trash dumping are also cited as a common threat.

Research and Management Summary:
A handful of individuals and institutions have researched this particular species, as well as a few closely related species. The New England Wild Flower Society regularly monitors populations of this species in New England.

Plant Description:
Eupatorium leucolepis var. novae-angliae is a robust plant, growing from a stout rhizome to between 40 cm and 1 meter in height. In July to mid-September, it bears white, composite flowers typical of the Aster family, with three to seven flowers in each head. Leaves are opposite on the hairy stem, and are fuzzy, lance-shaped, sharply toothed, tapering, and 3-8 cm long (these leaf characters distinguish this variety from its conspecific relative, Eupatorium leucolepis var. leucolepis. The plant can form dense colonies by proliferating on rhizomes, and this is its main mode of reproduction; however, it can form seeds asexually through agamospermy (Fernald 1950, Massachusetts Natural Heritage and Endangered Species Program 1986, DiGregorio 1991, Gleason and Cronquist 1991, Elliman in prep.).

Distribution & Occurrence


Conservation, Ecology & Research