July 24, 2017

Sticking Point

Barbara Lyon Photo | Onopordum acanthium - Cotton thistle or Scots thistle

Barbara Lyon Photo | Onopordum acanthium – Cotton thistle or Scots thistle

Onopordum acanthium looks innocent enough from a distance, but this member of the aster family is covered with spines, the botanical equivalent of needles. Scots thistle or cotton thistle is native to Europe and Asia, naturalizing elsewhere in the world, including most of the United States where it arrived during the 1800s. A good many states consider it an invasive plant, crowding out native species with ease. It can colonize an area rapidly; for instance, in Utah it was found “in 1963. By 1981, it covered approximately 6,070 hectares in 17 counties. Eight years later, it had spread to cover more than 22,540 hectares in 22 counties.” Interestingly, the plant is not listed as being in Maine by either the federal government or the New England Wild Flower Society. Scotch thistle is a biennial, producing a sturdy taproot during its first year before blossoming and spreading seed in its second year. The name cotton thistle stems from the plant’s cotton-like hairs on the leaves. Scots thistle is derived from the fact that thistle is the national emblem of Scotland.

Submitted by Barbara Lyon.

Editor’s Note: Do you have a plant you’d like to see on Garden Maine? Here’s our submission form.