R. Crowe, E. Hinman, T. Pollak, J. Woods
Fruiting and flowering
11-100
roadside
Open flowers ~ 1cm, varying stages of bud to open to seed.
San Diego County, California, US
Carduus pycnocephalus (common names include Italian thistle, Italian plumeless thistle, slender thistle and Plymouth thistle) is a species of thistle native to the Mediterranean region of Europe and Asia which has become a noxious weed in Australia, New Zealand, South Africa, South America, and North America, especially in California, where it is a C-listed weed by the California Department of Agriculture and a Moderate rating by the California Invasive Plant Council . It favors grasslands, woodlands,...
