Leaves and Fruits of Davidia (Cornales) from the Paleocene of North America

Abstract

Abstract Davidia, a genus that is now endemic to China, played a prominent role in Paleocene vegetation of mid-latitude North America that previously was overlooked. Davidia antiqua (Newberry) comb. nov. is now known from co-occurring leaves and fruits at eight localities in the Fort Union Group of North Dakota, Montana, and Wyoming. The leaves, for more than a century called Viburnum antiquum (Newberry) Hollick, conform to extant Davidia in the long petiole, cordate base, pinnate venation, basal secondary veins with regular branches to the margin, typically blunt, large marginal dentations with medial vein insertion, and closely spaced percurrent tertiaries. Fruits are borne singly on otherwise staminate inflorescence heads. The peduncle bears two prominent scars, well below the head, interpreted as the attachment points of large bracts. The fruit stones are ellipsoidal, composed of fibers, with six to eight single-seeded locules, each with an elongate dorsal germination valve. Vascular bundles are not a...