R. Crowe, E. Hinman, T. Pollak, J. Woods
Fruiting and flowering
Open flowers ~ 1cm, varying stages of bud to open to seed.
violet small flower
small spiky flowers
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,...