New York Ironweed
Vernonia noveboracensis
Click or tap the section titles below to learn more about this species!
CLASSIFICATION: What’s in a name?
Scientific Name: Vernonia noveboracensis. The species name, noveboracensis, means “of New York”—one of the states where this species lives!1
Common Name: New York ironweed. While New York references a location where it grows, why is it called ironweed? Perhaps this name comes from the rusty coloration of its seeds and fading flowers, or even from the toughness of its stem. What do you think?1
Family: Asteraceae (Aster Family). This is one of the largest plant families, with over 32,000 members! Plants in this family are also known as composites, referring to their flower heads which comprise two types of flowers: ray and disk florets. Disk florets are small flowers which are grouped tightly together in the center of the head, while ray florets resemble petals and are arranged around the margins. Some members of this family have both types of flower, while others have just one (ironweed has flower heads that consist entirely of disk florets!). The yellow center of a daisy is a dense cluster of disk florets, and the white “petals” are ray florets. Can you think of any other plants with composite flowers?2
IDENTIFICATION: What does it look like?
Average Height: 3-6 ½ feet
Description: A perennial plant with lance-shaped leaves which are 2½–12” long and ½–2½” wide, somewhat hairy on the underside and a bit rough on the upper side, and often toothed. Leaves alternate on a sturdy stem which branches during flowering, with bright purple flowers at the tips. Flowers are about ¼–½” across and consist of 20–65 disk florets (no ray florets!). Each seed has a brownish to purplish parachute-like pappus, which allows it to be dispersed by the wind like dandelions.1,2,3
Bloom time: Jul – Sep
Notes: New York ironweed (Vernonia noveboracensis) can be distinguished from the similar looking upland ironweed (Vernonia glauca) by a few characteristics: the pappus of New York ironweed is brown to purple rather than white to yellow, the leaves are 4–6 times as long as wide as opposed to 2½–3½ times, and it tends to grow in wet places instead of the upland habitats where upland ironweed is typically found. These species can hybridize, however, making identification more difficult.2
LOCATION: Where is it at home?
Range: Found throughout most of Virginia except for a few counties to the south and west.5 This is a species of the eastern United States—found from New York and Massachusetts south to Florida, and west as far as Kentucky and Mississippi.4
Geology/Soil: Most frequently associated with moist soils.2,5
Habitat: Found in a wide variety of wet to moist places, including floodplain forests, riverbanks, wet meadows, swamps, marshes, fields, and clearings. Grows best in part to full sun. Sometimes in moist upland forests.2,5
CONNECTIONS: What are its relationships to other plants, animals, and humans?
Flora associations: Usually found with a variety of other trees, shrubs, and herbaceous plants adapted for moist soils such as those in floodplains or wet meadows. These include silver maple (Acer saccharinum), boxelder (Acer negundo var. negundo), sycamore (Platanus occidentalis), cutleaf coneflower (Rudbeckia laciniata), rice cutgrass (Leersia oryzoides), giant goldenrod (Solidago gigantea), sedges (Carex spp.), smooth alder (Alnus serrulata), spicebush (Lindera benzoin), and mistflower (Conoclinium coelestinum).
Fauna associations: The bright purple flowers attract many different types of butterflies and bees, including a long-horn bee specialist, Mellisodes denticulatus, that prefers the white pollen of Vernonia over other flowers. Several moths and butterflies have caterpillars that feed on Vernonia noveboracensis, including the American lady (Vanessa virginiensis), ironweed borer moth (Papaipema cerussata), a tortricid moth (Paralobesia vernoniana), and the eupatorium borer moth (Carmenta bassiformis) which feeds on the roots!6,7 The parthenice tiger moth (Apantesis parthenice) uses toxins from ironweed to make itself unpalatable to predators!8 Other insects feed on ironweed, such as beetles, grasshoppers, aphids, and more.
Human associations: Over time, humans have found a variety of medicinal uses for Vernonia noveboracensis. The Cherokee make infusions to treat a range of issues, including stomach ulcers, menstruation prevention, pain after childbirth, and loose teeth.9
We want these plants to thrive and for everyone who gets to visit the park to enjoy them, so remember – don’t pick flowers or other parts of the plant!!
Bibliography & Definitions
1 “Vernonia Noveboracensis.” Missouribotanicalgarden.org, 2024, www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=277487. Accessed 2 Dec. 2024.
2 Weakley, A.S., J.C. Ludwig, and J.F. Townsend. 2012. Flora of Virginia. Bland Crowder, ed. Foundation of the Flora of Virginia Project, Inc., Richmond. Fort Worth: Botanical Research Institute of Texas Press, pp. 275, 407.
3 “North Carolina Botanical Garden – Vernonia Noveboracensis.” Floraquest.org, 2019, floraquest.org/plant/show.php?id_plant=VENO. Accessed 2 Dec. 2024.
4 “NatureServe Explorer 2.0.” Explorer.natureserve.org, 1 Nov. 2024, explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.136747/Vernonia_noveboracensis. Accessed 2 Dec. 2024.
5 “Digital Atlas of the Virginia Flora | Vernonia Noveboracensis (L.) Michx.” Vaplantatlas.org, 2024, www.vaplantatlas.org/index.php?do=plant&plant=2361&search=Search. Accessed 2 Dec. 2024.
6 “Vernonia.” Bugguide.net, 2024, bugguide.net/index.php?q=search&keys=vernonia. Accessed 2 Dec. 2024.
7 Gaden S. Robinson; Phillip R. Ackery; Ian Kitching; George W Beccaloni; Luis M. Hernández (2023). HOSTS (from HOSTS – a Database of the World’s Lepidopteran Hostplants) [Data set resource]. Natural History Museum. https://data.nhm.ac.uk/dataset/hosts/resource/877f387a-36a3-486c-a0c1-b8d5fb69f85a
8 Floyd, and Gray. “Upland Ironweed – Illustrated Plants of the Piedmont – Piedmont Discovery Center.” Piedmont Discovery Center, 2018, piedmontdiscoverycenter.org/featured_item/piedmont-native-plants/. Accessed 2 Dec. 2024.
9 “BRIT – Native American Ethnobotany Database.” Brit.org, 2024, naeb.brit.org/uses/search/?string=vernonia+noveboracensis. Accessed 2 Dec. 2024.
Definitions:
Composite: A member of the Asteraceae family.
Disk floret: One of the small, tubular flowers clustered in the center of a composite flower like a daisy or sunflower.
Ray floret: The petal-like flowers forming the outer ring of flowers in a composite flower.
Pappus: A parachute-like appendage attached to the seeds of some composites, aiding in wind dispersal. Dandelion seeds are a familiar example.