[2] It is an erect biennial (occasionally annual) plant growing up to 1.5 m tall, with a glaucous blue-green stem.

The leaves are arranged in decussate opposite pairs, and are lanceolate, 5–15 cm long and 1-2.5 cm broad, glaucous blue-green with a waxy texture and pale greenish-white midrib and veins.

While poisonous to humans and most livestock, goats sometimes eat it and are immune to the toxin.

[6] Away from its native range, it is widely naturalised in many regions, where it is often considered an invasive weed.

It is used in folk medicine as a remedy for cancer, corns, and warts and has purportedly been used by beggars to induce skin boils.