WILDFLOWERS OF NEW MEXICO

As the common name implies, the prominent, yellow spines on the pink to creamy white flower head help identify this 1–3 foot tall, well-armed plant. A dense covering of white hairs covers the stem, but the spiny phyllaries are hairless. Note the yellow spines on the leaves reach 3/4 inch long (20 mm).

FLOWERS: April–July. White, red, pink, or purple, tube-like, atop a rounded to oval-shaped head; phyllaries with a whitish mid-stripe and often with hairy margins; tipped with spines to 1/2-inch long (12 mm)

LEAVES: Alternate, smaller up the stem. Blades elliptic to lance-shaped, 4–12-inches long (10–30 cm) by 3/4–3-inches wide (2–8 cm), distinctively gray-hairy above, white-woolly below; blade with 8-15 pairs of lobes with yellow spines 1/8-3/4 inch long (5-20 mm); margins strongly wavy or undulate.

HABITAT: Dry, sandy, gravelly, clay, volcanic soils, pinyon-juniper, pine-oak woodlands, grasslands, roadsides, disturbed areas.

ELEVATION: 3,275-10,000 feet.

RANGE: AZ, CA, CO, KS, NE, NM, OK, SD, TX, UT, WY.

SIMILAR SPECIES: 12 native species of Cirsium in NM, 5 in 3 or less counties, and two introduced. Wavy-leafed thistle, C. undulatum, has spines on the phyllaries  only 3/16-inch long (2–5 mm), and leaves tipped with spines to 1/2-inch long (12 mm) and pronounced undulate margins. Parry’s Thistle, C. parryi, in moist soils at high elevations, has yellow flowers with hairy phyllaries. Several introduced thistles are major noxious weeds.

NM COUNTIES: Statewide except Lea County in low- to high-elevation, dry habitats.