Wild South Florida — Naturally Wild
shop the mall
The Ultimate Guide to the Outdoors and Environment in Broward, Collier, Martin, Miami-Dade, Monroe and Palm Beach counties.
Almanac Places to Visit
  Back Country Blog   The Outdoor Store Powered by Amazon     Follow us on Facebook
Lateflowering Thoroughwort
lateflowering manywort
Lateflowering thoroughwort, photographed at Lake Ida Park, Delray Beach, Palm Beach County, in September 2013.
lateflowering manywort

It is a bit of an odd name, lateflowering thoroughwort, Eupatorium serotinum. We're guessing here that the lateflowering part comes from the plant's habit of waiting until late summer and early fall to begin putting out flowers.

Its scientific name is a little easier to explain: Eupatorium honors Mithridates Eupator, King of Pontas, who in 115 BC supposedly used a member of the genus as an antidote for a common poison, serotinum meaning late.

Lateflowering thoroughwort is found thoughout most of the eastern and central United States, and in most Florida counties, where it is a native. It is found in open areas, both moist and dry but it also takes some shade. It usually grows singly rather than in clumps or colonies. Its flowers are small and white, but it puts out tons of them in small heads, which cluster at the end of stems, making the collective effect fairly spectacular. It can grow to eight feet tall, usually shorter; the leaves are lance-shaped, rough-textured with sawtooth edges.

The flowers attract insects looking for a sweet meal, including bees, beetles, butterflies and moths. At least one species of butterfly uses lateflowering thoroughwort as a host plant. The leaves are too bitter from most browsing mammals.

Lateflowering thoroughwort is toxic, but has been used in making medicines. The Houma people of Louisiana, for example, boiled the flowers to make a cure for typhoid. The Alabama used it to relieve stomach pains. A second common name is late boneset, deriving from the use of Eupatorium plants to treat dengue fever, sometimes called breakbone fever because of the intense pain it causes.

lateflowering manywort

It has a cousin, Eupatorium perfoliatum, common boneset, that was more widely used in traditional medicine to treat everything from snake bites to veneral disease to rheumatism. The two plants are close enough genetically that they will hybridize where their ranges overlap. German scientists have found that common boneset might stimulate the immune system, but we've not seen similar research concerning our guy.

Dengue fever, by the way, is a mosquito-borne disease found mainly in tropical places around the globe. It rarely occurs in the United States, where lateflowering thoroughwort and common boneset grow.

Lateflowering thoroughwort is a member of the aster, or Asteraceae, family. Other common names: tall boneset and lateflowering boneset.

Photographs by David Sedore
lateflowering manywort
Links for Lateflowering Thoroughwort
Unless otherwise stated, all photographs are property of the publishers and may not be used without their express permission.