In the introduction to my report on the Laramie flora of the Denver Basin I stated that that was the first of what was proposed to be a series of papers dealing with the stratigraphy and paleobotany of certain Upper Cretaceous and lower Tertiary plant-bearing formtions of the Rocky Mountain region. The present paper is the second of this series and deals with the flora of the Denver formation and certain identical or closely related formations that occur mainly in or adjacent to the Denver Basin of Colorndo. The additional formational units treated are the Arapahoe formation, the Dawson arkose, and the Middle Park formation.