Eutrochium fistulosum (trumpetweed)

Plate 1 figs. a–h · 8 separate observations

Eutrochium fistulosum, photographed by Sam Kieschnick — fig. a Sam Kieschnick, CC BY 4.0 / 2022-06-03 / obs. 203641324

Eutrochium fistulosum, photographed by mefisher — fig. b mefisher, CC0 1.0 / obs. 192622266

Eutrochium fistulosum, photographed by Michelle W. （鍾偉瑋） — fig. c Michelle W. （鍾偉瑋）, CC BY 4.0 / obs. 186363527

Eutrochium fistulosum, photographed by Surly Aardvark — fig. d Surly Aardvark, CC0 1.0 / obs. 155240423

Eutrochium fistulosum, photographed by Steven Lamonde — fig. e Steven Lamonde, CC BY 4.0 / obs. 155670967

Eutrochium fistulosum, photographed by nickajacket — fig. f nickajacket, CC0 1.0 / obs. 153539307

Eutrochium fistulosum, photographed by Andrew Conboy — fig. h Andrew Conboy, CC BY 4.0 / obs. 98777230

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Native range 29 botanical countries

Native distribution of Eutrochium fistulosum, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows. Regions too small to draw at this scale are marked with a dot.

Region	TDWG code	Continent
Alabama	ALA	NORTHERN AMERICA
Arkansas	ARK
Connecticut	CNT
Delaware	DEL
Florida	FLA
Georgia	GEO
Illinois	ILL
Indiana	INI
Kentucky	KTY
Louisiana	LOU
Maine	MAI
Maryland	MRY
Massachusetts	MAS
Michigan	MIC
Mississippi	MSI
Missouri	MSO
New Hampshire	NWH
New Jersey	NWJ
New York	NWY
North Carolina	NCA
Ohio	OHI
Oklahoma	OKL
Pennsylvania	PEN
Rhode I.	RHO
South Carolina	SCA
Tennessee	TEN
Texas	TEX
Virginia	VRG
West Virginia	WVA

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Flowering 318 in flower of 460 examined

34%

58%

94%

68%

33%

Proportion of examined Eutrochium fistulosum in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	2	too few examined
Feb	0	0	too few examined
Mar	0	7	0%	0% to 35%
Apr	0	6	0%	0% to 39%
May	0	11	0%	0% to 26%
Jun	11	32	34%	20% to 52%
Jul	78	134	58%	50% to 66%
Aug	195	207	94%	90% to 97%
Sep	28	41	68%	53% to 80%
Oct	5	15	33%	15% to 58%
Nov	1	4	too few examined
Dec	0	1	too few examined

Peak flowering in Aug. Each bar is the share of Eutrochium fistulosum observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 318 of 460 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 4 months have fewer than 5 examined observations, so no proportion is drawn for them. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

Where it actually grows measured, from 2,007 observations

Condition	5th percentile	Median	95th percentile
Coldest month, mean daily low	-7.8 °C	-3.4 °C	4.7 °C
Warmest month, mean daily high	25.1 °C	28.9 °C	32.5 °C
Annual rainfall	1,014 mm	1,222 mm	1,657 mm
Rainfall in the driest quarter	199 mm	258 mm	347 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 2,007 research-grade observations of Eutrochium fistulosum that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

Also published as 4 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

Eupatoriadelphus fistulosus (Barratt) R.M.King & H.Rob.
Eupatorium fistulosum Barratt
Eupatorium fistulosum f. fistulosum
Eupatorium purpureum var. angustifolium Torr. & A.Gray

Sourcesevery claim on this page

World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
USDA PLANTS Database. common name, checklist symbol EUFI14. public domain. Retrieved 2026-07-13.
Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.