Eutrochium maculatum explained

Eutrochium maculatum, the spotted joe-pyeweed, is a North American species of flowering plant in the family Asteraceae. It is widespread through much of the United States and Canada.^[1] It is the only species of the genus Eutrochium found west of the Great Plains.

This herbaceous perennial sometimes grows as high as 2m (07feet). Stems are sometimes completely purple, sometimes green with purple spots. One plant can produce numerous rose-purple flower heads in late summer, each head with 8-22 disc flowers but no ray flowers.^[2] The specific name maculatum, meaning spotted, refers to the purple spots on the stem.^[3]

Spotted joe-pyeweed thrives in marshes, rich fens and swamps. It also does well in man-made moist expanses such as ditches, seepage areas and wet fields. Above all else the plant flourishes in the non-shaded environments that are also abundant in wetlands.^[4]

It is a larval host to the Clymene moth, the eupatorium borer moth, the ruby tiger moth, and the three-lined flower moth.^[5] The plant also attracts butterflies and honeybees.^{[6] [7]}

Varieties

The following varieties are known:

• Eutrochium maculatum var. bruneri (A. Gray) E. E. Lamont - western Canada (British Columbia to Saskatchewan), western USA (Minnesota west to Idaho, south to Arizona + New Mexico)
• Eutrochium maculatum var. foliosum (Fernald) E. E. Lamont - eastern Canada (Newfoundland to Ontario), northern USA (Maine to Minnesota)
• Eutrochium maculatum var. maculatum - eastern Canada (Newfoundland to Ontario), eastern USA (Maine to Minnesota, south to northern Georgia)

Cultivars

The following cultivars are recipients of the Royal Horticultural Society's Award of Garden Merit (listed under the synonym Eupatorium maculatum):-

• (Atropurpureum Group) 'Orchard Dene' ^[8]
• (Atropurpureum Group) 'Purple Bush' ^[9]
• (Atropurpureum Group) 'Riesenschirm' ^[10]

Notes and References

1. http://planthardiness.gc.ca/index.pl?lang=en&m=7&speciesid=1004568 Eutrochium maculatum
2. Book: RHS A-Z encyclopedia of garden plants. 2008. Dorling Kindersley. United Kingdom. 978-1405332965. 1136.
3. Dickinson, T.; Metsger, D.; Bull, J.; & Dickinson, R. (2004) ROM Field Guide to Wildflowers of Ontario. Toronto:Royal Ontario Museum, p. 164.
4. Web site: Eutrochium maculatum var. maculatum . New York Flora Association . 2005 . 2008-09-24 .
5. The Xerces Society (2016), Gardening for Butterflies: How You Can Attract and Protect Beautiful, Beneficial Insects, Timber Press.
6. Web site: Eutrochium maculatum - Plant Finder. 2021-11-30. www.missouribotanicalgarden.org.
7. Web site: Eutrochium maculatum (Joe-Pye-weed, Queen of the Meadow, Spotted Joe-pye-weed, Spotted Trumpet Weed) North Carolina Extension Gardener Plant Toolbox. 2021-11-30. plants.ces.ncsu.edu.
8. Web site: Eupatorium maculatum (Atropurpureum Group) 'Orchard Dene' . RHS . 23 June 2020.
9. Web site: Eupatorium (Atropurpureum Group) 'Purple Bush' . RHS . 23 June 2020.
10. Web site: Eupatorium maculatum (Atroputrpureum Group) 'Riesenschirm' ]. RHS . 23 June 2020.