Silphium

Silphium as having thick roots covered in black bark, about 48 centimeters long, or one cubit, with a hollow stalk, similar to fennel, and golden leaves, like celery.

A mature plant has huge leaves, between 1–1.5 m (3 ft 3 in–4 ft 11 in) wide, and a stout, bright green stem with extensive yellow-green splotches and prominent coarse white hairs, especially at the base of the leaf stalk. Hollow, ridged stems vary from 3–8 cm (1.2–3.1 in) in diameter, occasionally up to 10 cm (3.9 in) in diameter and can grow to more than 4 m (13 ft) high. They look alot like Hogweed except for their daisy-like yellow composite flower heads.