SALT LAKE CITY -- As summer heats up, the sight of blooming thistles may give male goldfinches a testosterone kick. Thistle flowers could signal to American goldfinches that the seeds the songbirds ...

Thistles have reputations as especially prickly plants, and species found in Northcentral Texas and Southwestern Oklahoma are not exceptions. Some cultures and traditions have low regard for thistles.

SALT LAKE CITY — As summer heats up, the sight of blooming thistles may give male goldfinches a testosterone kick. Thistle flowers could signal to American goldfinches that the seeds the songbirds ...

Globe thistle’s pale purple to steel blue flowers, held high on stiff stems above coarse dark green foliage, are stealing the show this summer in gardens where they grow. Sea holly is a close second ...

In the mountains of southern Spain, one type of thistle plant seems to have built-in air conditioning. “Those are substantial coolings relative to the air next to it,” says Christopher Still, an ...