Introduced. Annual or biennial. Propagates by seeds.

Time of bloom: July to September.

Seed-time: August to October.

Range: New Brunswick and Nova Scotia to Ontario, southward to New Jersey and Ohio.

Habitat: Roadsides and waste places.

Said to be the heraldic plant of Scotland, but now probably more abundant in its adopted land than on its native heath. Stems three to nine feet tall, erect, stout, branching; the whole plant densely clothed all over with silvery white cotton wool. Leaves oblong lance-shaped, thick, irregularly lobed and toothed, decurrent on the stems, the margins and the broad basal wings edged with sharp, yellow-tipped spines. Heads terminal, solitary, large, broader than their height; florets purple; the outer bracts of the involucre narrowly oblong, with slightly roughened edges, and tipped with spreading yellow spines. Achenes faintly ribbed, the pappus brownish and bristly. (Fig. 357.) Means of control the same as for the Common Thistle.

Fig. 357.  Scotch Thistle (Onopor dum Acanthium). X 1/4.

Fig. 357.- Scotch Thistle (Onopor-dum Acanthium). X 1/4.