Yellow Star Thistle
Mediterranean; Naturalized in North America
Pollen of this plant was found in a Neanderthal gravesite, suggesting that St. Barnaby's Thistle was appreciated by man over 60,000 years ago.
Source of plant
Cornell Botanic Gardens, Index Seminum
A grayish-green plant with multiple rigid stems that extend in all directions from the base, forming a bushy-looking cluster that can reach two meters in height and more than that in diameter. It produces bright yellow flowers ringed with long, sharp spines. The plant grows quickly and is very competitive. It bears a taproot that can reach a meter deep into the soil, allowing it to thrive during dry, hot summers. It is versatile in its growth patterns, and can adapt to drought or low soil moisture content by producing smaller plants with fewer seeds during dry years. Since its introduction to California in the mid-nineteenth century, it has become a large-scale noxious weed throughout the United States, currently dominating over 15,000,000 acres (61,000 km2) in California alone.
USDA Hardiness Zone