Today’s photo and article come to us from Douglas Justice, Curator of Collections, UBCBG.
This sprawling evergreen shrub or climber is native to southern China. I’ve photographed a similar species (or perhaps the same one, but with orange flowers) in Washington DC, where it was cultivated as a summer bedding plant. Here, it is a background native plant in the Magnolia Collection at the South China Botanical Garden, in Guangzhou, China. You can also find it in the Medicinal Plants Area, Pu Gang Reserve, which is also part of this fantastic garden. According to the Dictionary of Chinese Traditional Medicine (1986), the plant has been used as a diuretic, antichloristic and antipyretic agent. It has also been employed against laryngopharyngitis, acute gastroenteritis and dysentery, and as a contraceptive.
The expanded, flag-like sepals are reminiscent of those borne on a number of familiar ornamentals, including hydrangeas, but more particularly, Schizophragma hydrangeoides. Such flag-like flower parts—at least the white ones—are adapted to increasing visibility for and hence, visitation by, moths, such as the magnificent Atlas moth, which is native to the same part of the world. The moths effect pollination and find a nectar "reward" at the base of the tubular flowers.