Pluchea carolinensis is also known as sourbush and cure-for-all. This latter name probably comes from its medicinal use in its native range, which is the tropical Americas. It’s a member of the aster family – Asteraceae.
The plant was first reported in Hawaii in 1931 and on the Big Island in 1933. It’s believed to be an accidental introduction, possibly associated with shipping to Hawaii and within the islands. The onset of World War II prompted the plant’s spread through the Pacific, probably in military shipments.
On the Big Island it’s most often seen in drier coastal areas, but it can tolerate a variety of climates and conditions. These photos were taken on the Puna Coast Trail in Hawaii Volcanoes National Park.
For more information about Hawaii Volcanoes National Park, go to nps.gov/havo/.