Lobelia oahuensis, commonly known as Oahu lobelia, is a rare and endangered perennial herb endemic to the island of Oahu in Hawaii. It is found in the moist and wet shrublands of the Koʻolau and Waianae Ranges, typically on windy slopes and ridgelines at elevations between 600 and 900 meters. This species is characterized by its rosette of lance-shaped leaves and strikingly long inflorescences, which can exceed one meter in length and bear numerous small, tubular blue flowers that are attractive to native birds. The flowering season occurs sporadically throughout the year, with each inflorescence lasting several weeks.

Oahu lobelia’s rarity and unique floral display make it a plant of significant conservation interest. In cultivation, it requires conditions that mimic its native habitat, such as well-draining soil, consistent moisture, and protection from strong winds. It is not commonly grown in gardens due to its endangered status and specific growing requirements, but it can serve as a focal point in native plant collections or conservation gardens. Efforts to propagate Lobelia oahuensis are crucial for its survival, as it faces threats from habitat loss and climate change.CC BY-SA 4.0