Dipteronia


Dipteronia is a genus of two living and one extinct species, regarded in the soapberry family Sapindaceae sensu lato after Angiosperm Phylogeny Group and more recently or traditionally by several authors in Aceraceae, related to the maples.
They are deciduous flowering shrubs or small trees, reaching 10–15 m tall.
The leaf arrangement is opposite and pinnate. The inflorescences are paniculate, terminal or axillary. The flowers have five sepals and petals; staminate flowers have eight stamens, and bisexual flowers have a two-celled ovary. The fruit is a rounded samara containing two compressed nutlets, flat, encircled by a broad wing which turns from light green to red with ripening.
The name Dipteronia stems from the Greek "di-" & "pteron", from the winged fruits with wings on both sides of the seed.
There are only two living species, Dipteronia sinensis and Dipteronia dyeriana; both are endemic to mainland China. Dipteronia dyeriana is listed by the as being a "Red List" threatened species.

Fossil record

Dipteronia browni is an extinct species from the early Eocene Klondike Mountain Formation of Washington, and is also known from early Eocene sites in British Columbia Canada such as Driftwood Canyon Provincial Park and the McAbee Fossil Beds.
Several fossil leaves and two winged fruits of Dipteronia brownii have also been collected from the early Oligocene lacustrine mudstone layers near Lühe Town in Chuxiong Yi Autonomous Prefecture of Yunnan Province, southwestern China.