Abeliophyllum Nakai

Abeliophyllum is an interesting monospecific genus from the central parts of the Korean peninsula: the description of A. distichum encompasses that of the genus.

Abeliophyllum has long been recognised to be closely allied to Forsythia and is placed with it in the tribe Forsythieae of the Oleaceae. Some confusion has been derived from the difference in fruit structure between the two genera, Forsythia having a dehiscent capsule while in Abeliophyllum the fruit is a round, winged indehiscent samara. In this it resembles Fontanesia, the only member of tribe Fontanesieae (Mabberley 2017) but the sister relationship of Forsythia and Abeliophyllum has been clearly confirmed by the molecular and morphological studies of Ha et al. (2018). The morphological and cytological similarities lie in the shared morphology of the corolla tube, heterostylous flowers and a basic chromosome number of × = 14, but the genera split in the Miocene, c. 16.6 million years ago (Ha et al. 2018).

The name Abeliophyllum references the similarity of the foliage to that of Abelia (and has been translated as a vernacular name to Abelialeaf in the United States): like the foliage of Abelia it is of no great distinction.