I know of no other wild plants that are poisonous to the touch; the following will poison only if taken inwardly.
Plants poison to the taste.
Deadly Nightshade
To the nightshade family belong plants that are poisonous and plants that are not, but the thrilling name, deadly nightshade, carries with it the certainty of poison.
The plant is an annual and you may often find it growing in a neglected corner of the garden as well as in waste places. It is a tall plant; the one I remember in our own garden reached to the top of a five-foot board fence. Its leaves are rather triangular in shape, they are dark green and the wavy edges are notched rather than toothed. The flowers are white and grow in small clusters. The fruit is a berry, round, black, and smooth, with calyx adhering to it. The berry clusters grow at the end of drooping stems. This must not be mistaken for the high-bush blueberry, for to eat the fruit would be most dangerous.
The antidotes for nightshade poison are emetics, cathartics, and stimulants. The poison should be thrown off the stomach first, then strong coffee be given as a stimulant.
Pokeweed, Pigeonberry
Pokeweed comes under the heading of poisonous plants though its berries are eaten by birds, and its young shoots are said to be almost equal in flavor, and quite as wholesome, as asparagus. It seems to be the large perennial root that holds the poison, though some authorities claim that the poison permeates the entire plant to a certain extent. The root is sometimes mistaken for that of edible plants and the young leaves for those of the marsh-marigold, which are edible when cooked. It is a tall plant with a stout stem and emits a strong odor. You will find it growing by the wayside and in rocky places. The leaves are oblong and pointed at the tips and base. They have no teeth. The small white flowers are in clusters. The fruit is a small, flat, dark-purple berry, growing in long, upstanding clusters on a central stalk. The individual stem of the berry is very short. The name inkberry was given to the plant because of the strong stain of the berry juice which was sometimes used for ink. Pokeweed is at home in various states, Maine to Minnesota, Arkansas, and Florida.