Description:

Leaves:

• alternate
• hair on underside and occasionally on the top surface
• wavy edges, with yellow spines

Stems:

• spiny, "winged" up to the base of the flowers
• may be densely hairy to nearly hairless

Flowers:

• purple, rarely white or yellow
• usually do not droop as in musk thistle
• base of flower head is covered with spiny bracts

Root:

• stout, fleshy taproot