North Carolina Botanical Garden

Plant Index

Scientific Name:
Common Name:
Genus:
Family:

Eupatorium rotundifolium

Eupatorium rotundifolium L.

roundleaf thoroughwort, common roundleaf eupatorium

Eupatorium rotundifolium (Roundleaf Thoroughwort)

Image ID: 14436
Image by: Sorrie, Bruce A.
Image Collection: NCBG Digital Library

PLANT INDEX

ID_PLANT: EURO4
SCIENTIFIC NAME: Eupatorium rotundifolium
Include in WOTAS: 1
Publish to Web: 1
Last Modified: 2018-09-25

GENUS INDEX

GENUS CODE: EUPAT
GENUS SCIENTIFIC: Eupatorium
GENUS AUTHORITY: L.
GENUS COMMON: Thoroughwort
GENUS SUMMARY: A genus of about 40 species, herbs, of e. North America and Eurasia (after the exclusion of Ageratina, Chromolaena, Conoclinium, Eutrochium, Fleischmannia, and other genera). I have differed considerably from Cronquists treatments, as for instance in SE, regarding the rank at which to recognize taxonomic entities in Eupatorium. In the Southeastern United States, Eupatorium is a reticulately evolved complex, including diploids, triploids, and tetraploids; derivatives of hybridization produce sterile pollen but in some cases reproduce vigorously via agamospermous production of seeds. In some cases, these entities form separate populations from their presumed parental species, with distinctive ranges and habitats and more-or-less distinctive morphology. Cronquist treats morphologically highly distinctive entities, such as E. pinnatifidum, as full species, while stating that they are not long-persistent. He treats morphologically more subtle entities as varieties of one of the two presumed parental species, such as E. album var. vaseyi (very probably derived by hybridization of E. album var. album and E. sessilifolium). Other entities, difficult to distinguish morphologically from another species, he does not recognize, as for instance E. saltuense, included as a synonym under E. altissimum (E. saltuense may reflect hybridization between E. altissimum and some other species such as E. album, or possibly between E. hyssopifolium and E. album].
GENUS IDENTIFICATION:
GENUS REFERENCES: Siripun & Schilling in FNA (2006c); Schilling (2011)=Y; Cronquist (1980)=SE; Godfrey (1949). The key adapted from those references. (also see Ageratina, Chromolaena, Conoclinium, Eutrochium, Fleischmannia)

FAMILY INDEX

FAMILY CODE: ASTERA
FAMILY SCIENTIFIC: Asteraceae
FAMILY AUTHORITY: Dumortier 1822 or COMPOSITAE Giseke 1792
FAMILY COMMON: Aster Family
FAMILY SUMMARY: A family of about 1500-1700 genera and 20,000-25,000 species, shrubs, herbs, trees, and vines, cosmopolitan in distribution.
FAMILY REFERENCE: Cronquist (1980)=SE throughout family treatment.

NCBG DESCRIPTIVES

INTRO: Erect perennial of savannas, seepage bogs, woodlands, interdune swales, old fields and roadsides.
STEMS: Stems 1-2 from a short crown, sparsely branched above and densely hairy, especially above.
LEAVES: Leaves mostly opposite, sessile, oval to triangular with somewhat rounded tip and nearly flat base, 1-1 1/2 times long as wide, with the principal pair of lateral veins diverging directly from the base of the midrib, round-toothed, rough-hairy above and gland-dotted and veiny beneath.
INFLORESCENCE:
FLOWERS: Small composite flowers (heads) arranged in clusters at branch tips, the branches and stalks hairy and glandular; heads about 1/4 in. wide and consisting of 5 white, tubular disk florets. 2 or 3 series of tiny, pointed bracts surround the base of each head.
FRUITS:
COMMENTS:
HEIGHT: 3-4 1/2 ft.

DURATION: Perennial
HABIT: Herb

LEAF ARRANGEMENT: Opposite
LEAF COMPLEXITY: Simple
LEAF RETENTION:

FLORAL CHARACTERISTICS
SYMMETRY: Mixed
BLOOM TIME: Aug-Oct

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
						x	x	x	x	x

BLOOM COLOR: White

White	Red	Pink	Orange	Yellow	Green	Blue	Lavender	Purple	Violet	Brown	Not Applicable
x

FRUITING PERIOD:

DISTRIBUTION
HABITAT TYPE: Bogs/pocosins, Disturbed, Pine savannas, Woods margins
NATIVE RANGE: eastern North America

HORTICULTURAL
Plant Sale Text: With interesting ovate to heart-shaped leaves that hug the stem in pairs and a showy flat-topped clump of white flowers, Roundleaf thoroughwort is a worthy addition to the garden. Found throughout the state of North Carolina, it is easy to establish and more compact than other species of Eupatorium such as boneset. Fluffy seeds provide winter interest for this mid-sized Eupatorium.

Bloom Table Text:

NCBG Location:

Cultural Notes:

SOIL MOISTURE: Dry, Average, Moist/Wet
LIGHT EXPOSURE: Sun, Part Shade
MINIMUM HARDINESS ZONE: 4
MAXIMUM HARDINESS ZONE: 8
GERMINATION CODE: 2
WILDLIFE VALUE: Bee Friendly, Butterfly Friendly
DEER RESISTANCE:

GRIM ACCESSIONS

acc_id	acc_num	acc_dt	coll_id	Action
292	2011-0155	2011-06-16	297	View
1932	1986-1718			View
4394	1992-0550			View

GRIM COLLECTIONS

Coll_id	Project	Collection date	Collector	Action
297	HORT	2009-01-01	NCBG staff	View
2207	NPMD	2019-09-09	Touloupas	View
2223	NPMD	2019-09-11	Touloupas	View
2268	NPMD	2019-10-01	Touloupas	View
2537	NPMD	2021-10-19	Pil	View
2552	NPMD	2021-10-06	Boyette	View
2726	NPMD	2022-10-05	Searles	View

GRIM PLANTINGS

plt_num	acc_id	loc_num	pers_num	inst_dt	Action
683	292	21	NCBG staff	2011-04-08	View
3072	1932	64	NCBG staff	1986-12-22	View
6722	4394	200	NCBG staff	1993-03-01	View

USDA PLANTS DATABASE

USDA Symbol: EURO4
USDA Common Name: Roundleaf Thoroughwort
Native Status: L48 (N)
Distribution: USA (AL, AR, CT, DC, DE, FL, GA, IN, KY, LA, MA, MD, ME, MO, MS, NC, NH, NJ, NY, OH, OK, PA, RI, SC, TN, TX, VA, WV)
Duration: Perennial
Growth Habit: Forb/herb

NATIONAL WETLAND INDICATOR STATUS

Region:	AGCP	AK	AW	CB	EMP	GP	HI	MW	NCNE	WMVE
Status:	FAC				FAC	FAC		FAC	FAC

This information is derived from the U.S. Army Corps of Engineers 2016 National Wetland Plant List, Version 3.3 (Lichvar, R.W., D.L. Banks, W.N. Kirchner, and N.C. Melvin. 2016. The National Wetland Plant List: 2016 wetland ratings. Phytoneuron 2016-30: 1-17. Published 28 April 2016. ISSN 2153 733X). Regions: AGCP-Atlantic and Gulf Coastal Plain, AK-Alaska, AW-Arid West, CB-Caribbean, EMP-Eastern Mountains and Piedmont, GP-Great Plains, HI-Hawaii, MW-Midwest, NCNE-Northcentral and Northeast, WMCV-Western Mountains, Valleys & Coast

WEAKLEY FLORA

SCIENTIFIC NAME: Eupatorium rotundifolium
COMMON NAME: Common Roundleaf Eupatorium
SYNONYMY: [= F, S, Va; = E. rotundifolium var. rotundifolium - C, FNA, G, K, Pa, RAB, SE, W; < E. rotundifolium - GW, WH3 (also see E. pubescens and E. cordigerum); E. rotundifolium Linnaeus ssp. rotundifolium]
PHENOLOGY: Aug-Oct.
HABITAT: Savannas, seepage bogs, woodlands.
COMMENTS: MA, NY, IN, and OK south to s. FL and TX.
RANGE MAP: Eupatorium rotundifolium.png

Key to Map Symbols

ABOUT FAMILY (Weakley Flora)
Asteraceae Dumortier 1822 or COMPOSITAE Giseke 1792 (Aster Family)
SUMMARY: A family of about 1500-1700 genera and 20,000-25,000 species, shrubs, herbs, trees, and vines, cosmopolitan in distribution.
REFERENCE: Cronquist (1980)=SE throughout family treatment.

ABOUT GENUS (Weakley Flora)
Eupatorium L. (Thoroughwort)
SUMMARY: A genus of about 40 species, herbs, of e. North America and Eurasia (after the exclusion of Ageratina, Chromolaena, Conoclinium, Eutrochium, Fleischmannia, and other genera). I have differed considerably from Cronquists treatments, as for instance in SE, regarding the rank at which to recognize taxonomic entities in Eupatorium. In the Southeastern United States, Eupatorium is a reticulately evolved complex, including diploids, triploids, and tetraploids; derivatives of hybridization produce sterile pollen but in some cases reproduce vigorously via agamospermous production of seeds. In some cases, these entities form separate populations from their presumed parental species, with distinctive ranges and habitats and more-or-less distinctive morphology. Cronquist treats morphologically highly distinctive entities, such as E. pinnatifidum, as full species, while stating that they are not long-persistent. He treats morphologically more subtle entities as varieties of one of the two presumed parental species, such as E. album var. vaseyi (very probably derived by hybridization of E. album var. album and E. sessilifolium). Other entities, difficult to distinguish morphologically from another species, he does not recognize, as for instance E. saltuense, included as a synonym under E. altissimum (E. saltuense may reflect hybridization between E. altissimum and some other species such as E. album, or possibly between E. hyssopifolium and E. album].
REFERENCE: Siripun & Schilling in FNA (2006c); Schilling (2011)=Y; Cronquist (1980)=SE; Godfrey (1949). The key adapted from those references. (also see Ageratina, Chromolaena, Conoclinium, Eutrochium, Fleischmannia)

HERBARIUM RESOURCES

SERNEC: Find Eupatorium rotundifolium in Southeast Regional Network of Experts and Collections (if available)
UNC SERNEC: Find Eupatorium rotundifolium in University of North Carolina Chapel Hill Herbarium - Southeast Regional Network of Experts and Collections (if available)

WEB RESOURCES

USDA: Find Eupatorium rotundifolium in USDA Plants
NPIN: Find Eupatorium rotundifolium in NPIN Database
FNA: Find Eupatorium rotundifolium in the Flora of North America (if available)
Google: Search Google for Eupatorium rotundifolium

IMAGE USE RECORDS

ID IMAGE: 14436 - Primary Image FloraQuest Plant Detail Page (Landscape Preferred)
ID IMAGE1: 14436 - Primary Image WOTAS
ID IMAGE2: 0 - Secondary Image WOTAS
ID IMAGE3: 8002 - Primary Image Plant Sale Sign (Landscape Only)
ID IMAGE4: 0 - Primary Image New Plant Sale Label (Portrait Only)