Fruits and Leaflets of<i>Wisteria</i>(Leguminosae, Papilionoideae) from the Miocene of Shandong Province, Eastern China

Abstract

Well‐preserved legume fruits and associated leaflets are described from the middle Miocene Shanwang Formation of Shandong Province, eastern China. They are assigned to the extant temperate genus Wisteria (Leguminosae, Papilionoideae), which is a deciduous climbing vine native to eastern Asia and eastern North America. Wisteria is one of many genera with an eastern Asian and eastern North American disjunct distribution. Based on fruit and leaflet architecture, two new organ species are established. Wisteria shanwangensis sp. nov. is proposed for the fossil fruits, which are similar to fruits of extant Wisteria sinensis and are the only confirmed occurrences of Wisteria fruit fossils from China. Wisteria taoiana sp. nov. is proposed for the co‐occurring leaflets. These two new taxa may represent the same Wisteria population in the Miocene Shanwang flora. Based on fossil records, Wisteria had a more northern distribution in the Neogene of the Northern Hemisphere than today, representing an archaic boreal lineage during the Miocene. We support the recognition of an independent tribe Wisterieae. Wisteria fossils have frequently been described in Neogene floras of China, Japan, and far eastern Russia, but not North America, which implies that eastern Asia may have been its initial center of diversification earlier in the Cenozoic.