Beefsteak plant is a nonnative, invasive species that should not be planted or allowed to spread. It is a branching, herbaceous annual that can be green, deep purple, or various shades in between. Purplish plants look something like garden coleus.
Flowers are small, white or light purple, in elongated, spikelike clusters to 6 inches long, arising from leaf axils, with each flower on a short stalk subtended by a tiny leaflike bract. The calyx has 5 pointed lobes; the corolla has 5 rounded lobes. Blooms August-October.
Leaves are opposite, on long stems, large, soft, ovate to oblong, coarsely toothed, the upper surface indented with veins, the lower surface with raised veins. Foliage is green or shades of purplish brown, highly aromatic.
Stems are lightly hairy, 4-angled, often purplish even on green plants.
Similar species: The many types of garden coleus tend to have leaves with rounded, not sharp teeth, with usually green or yellow banding or other marks on the leaves. Coleus leaves and stems tend to be thicker, and the flowers are different, too. Coleus rarely escapes cultivation.