Genus: Cirsium — thistle
Species of Cirsium are difficult to key because they often form hybrids. You may need to use technical descriptions in other floras to identify a species. References: Moore and Frankton (1974), Keil (2006).
Family
This genus’s species in New England
- Cirsium altissimum
- Cirsium arvense
- Cirsium discolor
- Cirsium flodmanii
- Cirsium horridulum
- Cirsium muticum
- Cirsium palustre
- Cirsium pumilum
- Cirsium vulgare
Visit this genus in the Dichotomous Key