Every catalog has a back room. This is ours: the plants we grow because someone should, not because anyone asked. A conifer that survives in a handful of Chinese villages and almost nowhere else. A tree extinct in the wild since Jefferson was president. Two intergeneric hybrids that exist because a plantsman wondered what would happen. A Proteaceae out of southeastern Australia that has no business growing in South Carolina, and does.

Nothing here is chosen for being easy, and several are chosen for the opposite reason. Torreya taxifolia is among the most endangered conifers on earth, hanging on along a few ravines of the Apalachicola, and every nursery-grown plant is one more copy of a species running short of them. Others are simply strange. Daphniphyllum holds leaves like a rhododendron drawn from memory. Kadsura ripens a fruit that looks assembled rather than grown. Dichroa febrifuga is a hydrangea cousin whose alkaloids were used against fevers in China for centuries before anyone in the West took an interest.

The list changes as plants come available and sell through. If you are the sort of gardener who reads a plant list the way other people read a menu, start here.