Eupatorium altissimum, commonly known as tall thoroughwort or tall boneset, is a perennial herb that is indigenous to the eastern and central United States and Canada. It is often found in open woodlands, meadows, prairies, and along roadsides, preferring calcareous (limestone-based) soils. This species can exceed 59 inches in height and is characterized by its upright form, clusters of small, fluffy white flowers that bloom from late summer to fall, and its hairy stems and leaves. The leaves are narrow, lanceolate, and sessile, with a rough texture. The flowers are not particularly showy but are known for attracting a variety of pollinators, including bees and butterflies.

Tall thoroughwort is valued for its ability to adapt to a range of soil conditions and its minimal maintenance requirements, making it a suitable choice for naturalized areas, wildflower gardens, and restoration projects. It is also recognized for its ecological role as a larval host for the three-lined flower moth. In cultivation, it prefers full sun to partial shade and can tolerate drought once established, although it thrives with regular moisture. While not commonly used in formal garden settings, it can be an interesting addition to pollinator gardens or native plant landscapes. It is generally free from serious pests and diseases but can spread aggressively in favorable conditions, potentially becoming weedy.CC BY-SA 4.0