Pokeweed is a member of the family Phytolaccaceae, and is a large herbaceous perennial plant, growing up to 2.5 metres (8 feet) in height over the course of a summer. One to several branches grow from the crown of a thick, white, fleshy taproot; Michael D. K. Owen describes the branches as "stout, smooth, [and] green to somewhat purplish". Simple, entire leaves with long petioles are alternately arranged along the stem.
Pokeweeds reproduce only by their large, glossy black, lens-shaped seeds, which are contained in a fleshy, 10-celled, purple-to-near-black berry that has crimson juice. The flowers are perfect, radially symmetric, white or green, with 4–5 sepals and no petals. The flowers develop in elongated clusters termed racemes. The seeds have long viability, able to germinate after many years in the soil.
Plant Type: Perennial herbaceous plant which can reach a height of 3 m (10 ft) but is usually 1.2 to 2 m (4 to 6+1⁄2 ft). The plant must be a few years old before the root grows large enough to support this size. The stem is usually red late in the season. There is an upright, erect central stem early in the season, which changes to a spreading, horizontal form later with the weight of the berries. The plant dies back to the roots each winter. The stem has a chambered pith.
Leaves: The leaves are alternate with coarse texture with moderate porosity. Leaves can reach 41 centimetres (16 inches) in length. Each leaf is entire. Leaves are medium green and smooth, with a distinct odor that many characterize as unpleasant.
Flowers: The flowers have 5 regular parts with upright stamens and are up to 5 millimetres (1⁄4 in) wide. They have white petal-like sepals without true petals, on white pedicels and peduncles in an upright or drooping raceme, which darken as the plant fruits. Blooms first appear in early summer and continue into early fall.
Fruit: A shiny dark purple berry held in racemose clusters on pink pedicels with a pink peduncle. Pedicels without berries have a distinctive rounded five part calyx. Fruits are round with a flat indented top and bottom. Immature berries are green, turning white and then blackish purple.
Root: Thick central taproot which grows deep and spreads horizontally. Rapid growth. Tan cortex, white pulp, moderate number of rootlets. Transversely cut root slices show concentric rings. No nitrogen fixation ability.
