Bidens asymmetrica, known as Ko’olau Range beggarticks, is endemic to the leeward side of the southeastern Ko’olau Mountains on O’ahu. The species is listed as imperiled, in part due to its restricted range. Plants grow in mid-moisture hardwood forests and woodland areas, typically on slopes or ridges between 300-600m (1000-2000ft.). Ko’olau Range beggarticks bloom in the spring and summer, with small inflorescences that quickly develop into fruit. In cultivation, these plants may bloom year round.
According to the Bishop Museum, 19 species of beggarticks occur on the Hawaiian islands. The group is collectively named ko’oko’olau in Hawaiian. The previous link details traditional uses of the Hawaiian beggarticks, including medical treatment for thrush, fungal diseases, and throat and stomach troubles (as a tea).
The Ko’olau Range, where this species is found, is a remnant of the Ko’olau shield volcano of O’ahu. Only the former western part of the volcano remains, as the eastern half slid into the Pacific Ocean and is spread across the ocean floor. In the millions of years since this event, erosion has shaped what remains. Geological explorers of the mountain range will also encounter xenoliths along with the landscape designated as a US National Natural Landmark.