Other related species may be found under their own names. Bittersweet nightshade is also known as European bittersweet or climbing nightshade. This plant grows from rhizomes and is a slender climbing or trailing perennial reaching 6 feet in length. Flowers are deep purple or bluish purple with flower stalk arising between the leaf nodes or opposite the leaves. Nearly round fruits turn red when mature and stay on the vines through mid winter.
Black nightshade is an annual herb with a tap root.
Stems are erect and much branched reaching 3 feet tall. Leaves alternate, ovate or lanceolate, and long-stalked. Immature berries and foliage are toxic, but ripe fruits are reportedly edible. Solanum ptycanthum may be more commonly found in the midwest since S. americanum appears to be more concentrated in the southern states. A perennial with a deep taproot and rhizome below ground.