''Eupatorium serotinum'', also known as late boneset or late thoroughwort, is a fall-blooming

herbaceous plant Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

native to North America. ''Eupatorium serotinum'' ranges throughout most of the eastern United States, found in every coastal state from

Massachusetts Massachusetts (Massachusett language, Massachusett: ''Muhsachuweesut assachusett writing systems, məhswatʃəwiːsət'' English: , ), officially the Commonwealth of Massachusetts, is the most populous U.S. state, state in the New England ...

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

and inland as far as

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...

and

Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the southwe ...

. There are reports of one small population in the Canadian Province of

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central Ca ...

, and other reports of the species on the south side of the

Río Grande The Rio Grande ( and ), known in Mexico as the Río Bravo del Norte or simply the Río Bravo, is one of the principal rivers (along with the Colorado River) in the southwestern United States and in northern Mexico. The length of the Rio G ...

in northern Mexico. Like other members of the genus ''

Eupatorium ''Eupatorium'' is a genus of flowering plants in the family Asteraceae, containing from 36 to 60 species depending on the classification system. Most are herbaceous perennials growing to tall. A few are shrubs. The genus is native to temperate ...

'', ''Eupatorium serotinum'' is about one to two meters (40–80 inches) tall and has

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

s containing a large number of tiny white

flower heads A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, compos ...

with 9–15

disc floret The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...

s but no

ray florets The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...

. ''Eupatorium serotinum'' grows in open sites (either dry or moist), and can hybridize with ''

Eupatorium perfoliatum ''Eupatorium perfoliatum'', known as common boneset or just boneset, is a North American perennial plant in the family Asteraceae. It is a common native to the Eastern United States and Canada, widespread from Nova Scotia to Florida, west as far ...

'' and other members of the genus ''Eupatorium''. Unlike wind-pollinated plants in this genus, ''E. serotinum'' is pollinated by insects.

References

External links

Photo
from the Ozarks Regional Herbarium of

Missouri State University Missouri State University (MSU or MO State), formerly Southwest Missouri State University, is a public university in Springfield, Missouri. Founded in 1905 as the Fourth District Normal School, it is the state's second largest university by enr ...

Photo of herbarium specimen at Missouri Botanical Garden, collected in Missouri in 1993

From the blog "Nadia's Backyard
a native plant blog in central Missouri. serotinum Flora of North America Plants described in 1803 {{Eupatorieae-stub

References

Further reading

External links