No garden should be without ornamental potatoes. No, not the ones with fancy tubers: They're ornamental on your plate, not in the garden. Rather, ones with showy foliage, flowers, or fruits—or scary-wonderful thorns.
Here's another of the floriferous species: Paraguay nightshade. Purple-indigo flowers tip almost every stem in active growth, and if you grow the shrub year to year, you can train it into a standard or even a small tree.
Mine is in a pot, and this year it wound up amid most intriguing neighbors.