Invasive Species: Hieracium caespitosum, Meadow Hawkweed
Meadow hawkweed is an invasive perennial plant in the sunflower family (Asteraceae). It grows from 1 to 3 ft. (0.3 to 0.9 m) tall and produces a milky sap when crushed. Leaves are mostly basal, lance-shaped, hairy, 2 to 10 in. (5.1 to 25.4 cm) long and 1 in. (2.5 cm) wide. Flowers are yellow and dandelion-like; they develop in summer to fall. Seeds are black and tiny with an whitish pappus. Meadow hawkweed is native to Europe and occurs in fields, roadsides, and sparse woodlands. It was first found in the United States in Washington state in 1969.
What are invasive species and why should we be concerned about them?
Taxonomy: Scientific and Common Names for This Species
Asterales > Asteraceae > Hieracium caespitosum Dumort.
Synonym(s): yellow hawkweed
Hieracium caespitosum – USDA PLANTS Profile
Distribution Maps
Meadow hawkweed – The reported distribution of this invasive species across the United States. (Source: Invasive Plant Atlas of the United States)
Up-to-the-minute distribution maps and why they are important
Reporting This Invasive Species
What is the best way and place to report the occurrence of an invasive species?
How to report an invasive species sighting to EDDMapS – Early Detection & Distribution Mapping System
EDDMapS – Report an invasive species to EDDMapS
Cooperative Extension Offices – Find local Cooperative Extension office on this map provided by USDA
How to Identify
This invasive species can be identified by looking for the characteristics described in the paragraphs that follow.
Plant
Meadow hawkweed is an invasive perennial plant in the sunflower family (Asteraceae). It grows from 1 to 3 ft. (0.3 to 0.9 m) tall and produces a milky sap when crushed.
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| Michael Shephard, USDA Forest Service bugwood.org |
Linda Wilson, University of Idaho, bugwood.org |
Foliage
Leaves are mostly basal, lance-shaped, hairy, 2 to 10 in. (5.1 to 25.4 cm) long and 1 in. (2.5 cm) wide.
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| Tom Heutte, USDA Forest Service, bugwood.org |
Tom Heutte, USDA Forest Service, bugwood.org |
Flower
Flowers are yellow and dandelion-like; they develop in summer to fall.
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|
oseph M. DiTomaso, University of California – Davis, bugwood.org |
Tom Heutte, USDA Forest Service, bugwood.org |
Fruit
Seeds are black and tiny with an whitish pappus.
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| USDA NRCS PLANTS Database, bugwood.org | bugwood.org |
Native Species That Resemble Meadow Hawkweed
All species within this genus, including natives, are designated as noxious weeds.
Hieracium gronovii, gronovius hawkweed – Images at invasive.org
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| James H. Miller & Ted Bodner, Southern Weed Science Society, bugwood.org | James H. Miller & Ted Bodner, Southern Weed Science Society, bugwood.org |
– Images at invasive.org
| bugwood.org | bugwood.org |
Additional Images for Meadow Hawkweed
Meadow hawkweed – Images at Invasive.org
Learning Resources for Meadow Hawkweed
Additional Information, Biology, Control and Management Resources
Control and management recommendations vary according to individual circumstances. Location, habitat, weather, and a variety of other conditions are factors that help determine the best treatment choice. To find the safest and most effective treatment for your situation, consult your state’s land-grant institution. If you will use chemicals as part of the control process, always refer to the product label.
United States Land-Grant University System – Find your land-grant university’s College of Agriculture, Cooperative Extension Service, or other related partner on this map provided by USDA.
Fire Effects Information System – USDA Forest Service
Noxious Weeds – King County
Hieracium caespitosum (Meadow Hawkweed) – Minnesota Wildflowers
Hieracium caespitosum – North Carolina Cooperative Extension
Invasive.org – Center for Invasive Species and Ecosystem Health