‘Firefly’ is a self clinging climbing hydrangea aptly named for its bright yellow variegated leaves which give the effect of lightning bugs. It reaches an average length of 40 feet with flat white flowers in May and June. It is most valued for its striking foliage of dark green contrasted with bright yellow. It does well in full sun to light shade and is moderately drought tolerant . This is a cultivar of Hydrangea anomala ssp. petiolaris which is native to Japan, China, South Korea and eastern Siberia. The subspecies name petiolaris refers to the long petioles of this plant.