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Swamp Thistle
Cirsium muticum

Family: Asteraceae (ass-ter-AY-see-ee) (Info)
Genus: Cirsium (SIR-see-um) (Info)
Species: muticum (mu-tee-kum) (Info)




36-48 in. (90-120 cm)

4-6 ft. (1.2-1.8 m)

6-8 ft. (1.8-2.4 m)


Unknown - Tell us


Unknown - Tell us

Sun Exposure:

Full Sun

Sun to Partial Shade


Unknown - Tell us

Bloom Color:


Magenta (Pink-Purple)

Bloom Time:

Mid Summer

Late Summer/Early Fall

Mid Fall


Unknown - Tell us

Other details:

May be a noxious weed or invasive

This plant is attractive to bees, butterflies and/or birds

This plant may be considered a protected species; check before digging or gathering seeds

Flowers are good for drying and preserving

Provides winter interest

Soil pH requirements:

Unknown - Tell us

Patent Information:

Unknown - Tell us

Propagation Methods:

Unknown - Tell us

Seed Collecting:

Unknown - Tell us


This plant has been said to grow in the following regions:

Cedar Falls, Iowa

Gardeners' Notes:


On Jul 21, 2007, dkm65 from Cedar Falls, IA (Zone 4b) wrote:

I would give this a positive, except that it is unfortunately on a couple state's noxious weed list (Arkansas & Iowa) along with every other thistle, native or non-native. It is Native from North Dakota to Texas and east. It is a wetland obligate, so suitable to wet or wet mesic soil conditions. Ironically, it is listed as threatened in Arkansas. It is also ironic that Iowa's state bird is the American goldfinch, which prefers thistle seed to just about anything else and yet Iowa tries to eliminate all thistles (goldfinches also line their nests with thistle flower fibers).

It is an important nectar plant for fritillary butterflies, some of which are species of concerned or locally threatened. It is not aggressive, as it is kept in check by a host of native herbivorous ... read more