Thornapple is a coarse, branching plant, knee- to waist-high, with a stout, smooth, often purplish stem and large, soft, unevenly toothed leaves, dark green and dull, that smell foul when brushed, like rotten meat and old tobacco. In summer it opens single, long, trumpet-shaped flowers, white or pale violet, twisting open at dusk and giving off a sweet scent at night quite unlike the leaves. The fruit is an egg-sized green capsule covered in stiff spines, which dries brown and splits into four to spill hundreds of small, dark, kidney-shaped seeds.

It grows on rich, disturbed ground: ruin-courts and the rubble of old works, middens, yards, and the waste ground behind towns, throughout the Marches and in Lowbank’s yards at the Greyford Reach. It comes up in new rubble the first summer after a collapse.

It is a fast annual that seeds heavily, and once in a court it is hard to be rid of. Beasts leave it alone.

It sprouts in late spring, flowers through summer, and dies at the first frost; its seed lies in the ground for years.

Every part is poison, the seeds most. A child who eats the seeds, or a forager who mistakes the leaves for greens, grows hot, dry, and flushed, with wide black eyes and a racing heart, then raves and sees what is not there, sometimes for days; many children die (the course is much like the black-eyed berries under Poison Herbs). Healers burn a little of the dried leaf for those whose breath tightens, and some poisoners use the seed.

Dream-workers want the smoke. A careful measure, burned in a closed room in a smoke rite, opens a sleeper to dreams of terrible vividness, and some workers use it to reach a dreamer who will not otherwise go deep. It is hard to measure, the visions often turn to nightmare, and dream-workers who use it too often begin to see things awake. Most schools forbid it to students; most masters keep some.

Marches folk call it the devil’s trumpet and say it grows where someone died badly in the ruin, which is often true of ruins. Goblin gatherers sell it to dream-workers and will not burn it at their own hearths, and they say a buyer who comes back too often for it is not buying for dreams. Dream-workers hold that its visions come from the far edge of the Dreaming Veil; the poison does more of the work than the Veil does.

Marches camps warn of the delver who smoked thornapple to find a ruin’s hidden vault in a dream, walked off a broken stair in the night, and was found at the bottom of it beside the vault’s door, is told in every Marches camp.