Vegetative and reproductive morphology of Othniophyton elongatum (MacGinitie) gen. et comb. nov., an extinct angiosperm of possible caryophyllalean affinity from the Eocene of Colorado and Utah, USA.

Background And Aims: Eocene foliage formerly attributed to the extant araliaceous genus Oreopanax was found attached to twigs bearing inflorescences and infructescences unlike those of Araliaceae. Using newly observable characters of phyllotaxy, vegetative and floral buds, infructescences and seeds, we sought to reassess the affinities of this strange angiosperm.

Methods: Fossils were studied from the Parachute Creek Member of the Green River Formation from near Bonanza, Utah and Douglas Pass, Colorado (ca.