Since the founding of the genus Pieris by David Don exactly a century ago, with P. formosa as the type species (Bot. Mag. t. 8283), a remarkable diversity of plants has been included in it. True species of Pieris can, however, be readily distinguished from all pretenders by their firmly coriaceous, serrulate leaves, and by the racemes being aggregated into terminal generally leafless panicles. Thus limited, the genus contains, so far as is known, some half- dozen species, morphologically well defined and geographically isolated. Two are natives of the New World: P. floribunda (Pursh) Benth. & Hook. f., in the south-eastern United States (Bot. Mag. t. 1566), and P. cubensis (Griseb.) Small, confined to the island of Cuba. Japan has one species, P. japonica (Thunb.) D. Don; Formosa is the home of P. taiwanensis Hayata (Bot. Mag. t. 9016); and P. Swinhoei Hemsl. occurs in the coastal provinces of south-eastern.

Syn. P. Forrestii Harrow in Notes Roy. Bot. Gard. Edinb. VIII. 196 (1914). Since the founding of the genus Pieris by David Don