Typification of the genus Zizyphoides Seward et Conway (Magnoliophyta, Trochodendraceae)

Abstract

Type material of Paliurus colombii Heer, Populus arctica Heer, Hakea arctica Heer, and Hedera macclurii Heer from the Atanikerdluk locality (Paleocene, Greenland) was restudied based on the original collection, stored in the National Museum of Ireland, Dublin. All these species were joined under the name Zizyphoides colombii (Heer) Seward et Conway, type species of the genus Zizyphoides Seward et Conway. A lectotype of Zizyphoides colombii is designated and the diagnosis of this species is emended. An emended diagnosis of the genus Zizyphoides is also presented.