Thistles Found in the Columbia River Gorge
Wavy-leaf thistle: Cirsium undulatum
1. Canada Thistle: Cirsium arvense -
2. Mountain Thistle: Cirsium callilepsis (C. centaureae) -
3. Weak Thistle: Cirsium remotifolium -
4. Wavy-leaf Thistle: Cirsium undulatum - Wavy-leaf Thistle is a stout, single-stemmed short-lived perennial. The stem may be branched above, and stems range from 30-120 cm tall. All surfaces of the stem and leaves are persistently white-woolly haired, although the upper leaf surfaces may be less covered, and occasionally may be glabrous. The stems, leaves and flower heads are covered with sharp spines.
5. Bull Thistle: Cirsium vulgare -