Bonamia menziesii, commonly known as Hawaiʻi lady's nightcap, is a species of flowering plant in the morning glory family, Convolvulaceae, that is endemic to Hawaii. It is a vine or twisting liana with branches that can reach 10 m (33 ft) in length. Hawaiʻi lady's nightcap inhabits steep slopes and level ground in dry, coastal mesic, mixed mesic, and, sometimes, wet forests at elevations of 150–625 m (492–2,051 ft). Scattered populations exist on most main islands, but the total number of individuals remaining is probably fewer than 1000.