Cirsium suwoense is a spring-flowering thistle inhabiting slopes along mountain streams with a 60-150cm height, branches extending somewhat angularly, and no radical leaves in its flowering time. On-stem leaves on the lower and middle parts are large, measuring 32-58cm in length and 21-33cm in width, and are oblong-shaped. They are deeply cut into 4-10 pairs of lobes halfway pinnately, long-oblong-like lanceolate, 15-17cm long, 3-6cm wide, with long, 17-1cm petioles, and the basal parts slightly embracing the stems. Red-purple flower heads are set on 2-10cm pedicels that nod. Bloom time: May-June.