Winged fruits of rutaceous affinity from the Eocene of western North America
Abstract
A new kind of fin-winged fruit is recognized from lacustrine shales of the early Eocene Tepee Trail Formation of northwestern Wyoming and from the middle Eocene Clarno Formation of central Oregon, USA. The fruits are obovate with five thick lateral wings, borne on a thick pedicel and bearing scars of hypogynous perianth and disk. The fruit surface is covered with small circular dots interpreted as glands. This combination of characters leads us to infer affinities with the Rutaceae, although no identical modern genus is known. We establish the new genus and species, Quinquala obovata.