Date Published: February 1, 2017
Publisher: Public Library of Science
Author(s): Bine Xue, Yun-Yun Shao, Richard M. K. Saunders, Yun-Hong Tan, William Oki Wong.
Alphonsea glandulosa sp. nov. is described from Yunnan Province in south-west China. It is easily distinguished from all previously described Alphonsea species by the possession of glandular tissue at the base of the adaxial surface of the inner petals. Nectar was observed throughout the flowering period, including the pistillate phase and subsequent staminate phase. Small curculionid beetles were observed as floral visitors and are inferred to be effective pollinators since they carry pollen grains. A phylogenetic analysis was conducted to confirm the placement of this new species within Alphonsea and the evolution of the inner petal glands and specialized pollinator reward tissues throughout the family.
The genus Alphonsea Hook. f. & Thomson (Annonaceae) currently comprises 27 species of shrubs or trees, distributed in wet tropical lowland forests across south and south-east Asia, from India to the Philippines. It is characterized by flowers with saccate petals, ‘miliusoid’ stamens (sensu ) and multi-seeded fruits . Keßler  recognized 23 species in his taxonomic treatment of the genus, although four additional species were subsequently described from Vietnam , Papua New Guinea , Borneo , and Peninsular Malaysia . Six species have been recorded from China (A. boniana Finet & Gagnep., A. hainanensis Merr. & Chun, A. mollis Dunn, A. monogyna Merr. & Chun, A. squamosa Finet & Gagnep., and A. tsangyuanensis P. T. Li), distributed in Guangdong, Guangxi, Guizhou and Yunnan Provinces [7,8], although A. squamosa has been treated as a synonym of A. boniana .