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Sonchus asper (L.) Hill

Common Name: PRICKLY SOW-THISTLE
Coefficient of Conservatism: *
Coefficient of Wetness: 3
Wetness Index: FACU
Physiognomy: Ad A-Forb

Roadsides, railroads; a weed of cultivated fields and gardens; disturbed sites, including gravel pits, construction sites; disturbed deciduous forests, especially along trails and recent clearings; shores, marshy ground, river banks. Collected by the First Survey (1838) in Lenawee Co. and by 1888 collected in Keweenaw Co., so obviously long established in Michigan.

This species seems to set fruit well in this area, so the distinctive very compressed and smooth achenes are often available for positive identification. The large almost coiled auricles are often striking, especially as they, like the rest of the leaf margin, have prickles that tend to be longer, stiffer, and more numerous than in the other two species. Occasional plants with gland-tipped hairs as in S. arvensis var. arvensis may be called f. glandulosus Beckh.

R. Schipper

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Counties
Alger
Allegan
Alpena
Benzie
Berrien
Calhoun
Cass
Charlevoix
Cheboygan
Chippewa
Clinton
Emmet
Gogebic
Grand Traverse
Gratiot
Hillsdale
Houghton
Ingham
Iosco
Isabella
Jackson
Kalamazoo
Kent
Keweenaw
Lake
Lapeer
Leelanau
Lenawee
Luce
Mackinac
Macomb
Manistee
Marquette
Mason
Mecosta
Midland
Monroe
Ontonagon
Presque Isle
Roscommon
Schoolcraft
St. Clair
Van Buren
Washtenaw
Wayne

Citation:
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. March, 17, 2025
https://lsa-miflora-p.lsait.lsa.umich.edu/#/record/474