Cirsium palustre, commonly known as marsh thistle or European swamp thistle, is an herbaceous biennial or perennial plant. It is native to damp grasslands, marshes, and wet woodlands across Europe and Asia. This thistle typically grows up to 7 feet tall with strong, spiny stems and few branches. In its first year, it forms a rosette of narrow, spiny leaves, which in the second year develop into more deeply lobed leaves. From June to September, it produces dark purple flowers with purple-tipped bracts, which are highly attractive to pollinators. The flowers are showy and provide abundant nectar, earning the marsh thistle top ratings for nectar production in a UK plants survey.

The marsh thistle is valued for its wildlife benefits, particularly for supporting pollinator populations. It is used in naturalistic plantings and wildlife gardens, where its tall stature and striking flowers can provide visual interest. It prefers consistently moist soils and can tolerate waterlogged conditions, making it suitable for riparian plantings. It thrives in full sun to part shade. While generally low-maintenance, it can be prone to rust and other fungal diseases. Due to its invasive potential, caution is advised when planting it outside its native range.CC BY-SA 4.0