Physiognomy and Structure: No Data Available

Floristics: The vegetation is dominated by medium-tall (0.5-1 m) forbs. The dominant forb is Cirsium arvense, a naturalized species from Eurasia (Great Plains Flora Association 1986). Other weedy species may occur as well, but native species are generally less than 10% cover. Native species may include mixed-grass prairie grasses, such as Pascopyrum smithii and Hesperostipa comata (= Stipa comata), as well as others. In semi-arid and arid regions, sites tend to be relatively mesic and include many mesic species such as Carex utriculata, Hordeum jubatum, Juncus arcticus, and Juncus arcticus ssp. littoralis (= Juncus balticus). Scattered woody species may also be present, such as Populus angustifolia, Populus deltoides, Salix exigua, and Salix geyeriana on riparian and palustrine sites, and Ericameria nauseosa may be common on disturbed sites. Where native species are conspicuous enough to identify the native plant association that could occupy the site, the stand should be classified as such. Other introduced species include Bromus inermis, Conyza canadensis, Elymus repens, Linaria vulgaris, Schedonorus pratensis (= Festuca pratensis), Marrubium vulgare, Medicago sativa, Phalaris arundinacea, Phleum pratense, Poa pratensis, Rumex crispus, Thlaspi arvense, and Verbascum thapsus. This type could be defined very broadly to include almost any Cirsium arvense-dominated stand, in which case the variability of the minor species associated with the type would be very high.

Dynamics:  No Data Available