Triosteum perfoliatum, commonly known as perfoliate tinker's-weed,[1] late horse gentian,[2] common horse gentian,[3] perfoliate-leaved horse-gentian,[4] feverwort,[5] and wild coffee,[6] is a species of flowering plant belonging to the family Caprifoliaceae (honeysuckle).

[2] The genus name Triosteum is a shortened form of the Greek word "triostospermum", meaning "three stony seeds".

The specific epithet perfoliatum is from the Latin meaning "through the leaf", referring to the way the stem comes through each pair of joined leaves.

[8] T. perfoliatum is native in the United States from Nebraska to the west, Louisiana to the south, Massachusetts to the east, and the Canadian border to the north.

[8] The flowers of T perfoliatum bloom May to July and attract various bees, particularly bumblebees (Bombus spp.)