Scientific Name: Solanum ptycanthum

Common Name: eastern black nightshade

Other Common Names: west Indian nightshade, colorado bur, kansas thistle, Mexican thistle, Texas thistle

Synonyms: Solanum americanum, Solidago nigrum (auct. non L.)

Habit: Eastern black nightshade is a summer annual that grows to be about one foot high. It germinates from seeds and can grow late into summer and into early fall. It is hardy and resists light frosts.

Leaves: The young leaves of eastern black nightshade have undersides that are a maroonish-purple color. The shape is ovate or ovate-lancelote. They may be bluntly toothed and are often slightly hairy. Mature leaves are 2 to 4 inches (5 to 10 cm) long and 1 to 2 inches (2 to 5 cm) wide.

Identifying Characteristics: Underside of leaves are purple to almost black and young leaves are often maroon to purple colored. Fruit is a deep purple almost black color upon maturity.

Flower Seed Head: The flower of eastern black nightshade is about 1 to 2 centimeters in diameter. They are in clusters of 5 to 7, and are white or tinged purple.

Seed Fruit: The fruit of eastern black nightshade is a berry. It is approximately 5 to 12 millimeters in diameter. The berry is green when immature and turns to a deep purple when mature. The berries contain scleroic seeds, usually between 4 and a dozen.

Where Found: Eastern black nightshade is found throughout North America, though it is most common to the Eastern states, and is not usually west of the Rocky Mountains. This species usually found growing in pastures, along fence rows, roadsides, open woodlands, and fields.

  • Life cycle: summer annual

  • Milky sap: Not Present

  • Plant type: Herb

  • Thorns: Not Present

  • Plant family: Solanaceae

  • Leaf arrangement: alternate

  • Leaf shape: lance; oval; triangle

  • Ochrea: Not Present

  • Leaf margin: serrated; entire; lobed

  • Stem hairs: no hairs

  • Flower color: white; purple

  • Growth habit: upright and nonwoody

  • Stem: square or multi-edged; round or oval

  • Leaf structure: simple

  • Leaf hairs: no hairs; has hairs

  • Flower symmetry: radial symetery

  • Flower diameter: dime; pencil

  • Root structure: taproot; fibrous

  • Leaf stalk: shorter than leaf