[3] Carduus nutans is a monocarpic herb and is classified as a biennial thistle, though it can have varying phenology depending on climate and habitat.

[9][10] The plant bears showy flowers that range from a deep rose to violet color, rarely white.

The flower heads commonly droop to a 90° to 120° angle from the stem when mature, hence its alternate name of "nodding thistle".

[14][15] It typically grows in meadows and grasslands, in heavily grazed land in areas such as pastures, and on open disturbed soil such as roadsides and building sites.

It spreads rapidly in areas subjected to frequent natural disturbances such as landslides and flooding, but does not grow well in excessively wet, dry, or shady conditions.

Classified as a biennial, it can also act as a summer or winter annual, as well as a perennial, depending on varying environmental conditions.

[8] C. nutans is an invasive species in various regions around the world, including in disturbed and agricultural settings, pastures, rangelands, along roadsides, and in natural habitats.

[19][21] Pastures and rangelands suffer from decreased productivity and the sharp spines of the plant make an unsuitable grazing area for livestock.