The Fruitland-Kirtland Formations in the San Juan Basin contain an excellent record of Late Campanian-early Maastrichtian macrofloras deposited in a floodplain setting. The fossil material consists primarily of leaf compressions, and cuticle is well-preserved at some sites that are high in clay content. Although pteridophytes, gymnosperms, monocots and dicots comprise the macroflora as a whole, at these sites only dicot cuticle was preserved. In this study, cuticle was removed from more than15 specimens representing at least five different leaf morphotypes from four sites, and prepared using standard techniques. Epidermal cells and stomata generally have random orientations except over major veins. Stomatal types include paracytic and cyclocytic with some variation on individual specimens. Trichome bases are present on most specimens, and some have distinct secretory glands. Papillae were present to varying degrees on the upper and lower surfaces of all specimens. In a few specimens, surface papillae overhang the stomatal pore. Cuticle striations over some of the subsidiary cells were perpendicular to the long axis of the guard cells. Most of these features are consistent with families belonging to the Magnoliidae and comparisons with leaf architecture and extant families will be discussed. This represents the first description of cuticle from this flora, and with other information from entire leaves, permineralized wood, and palynology, provides a more complete vegetative record of this Late Cretaceous floodplain environment.

Key words: cuticle, Late Cretaceous, macroflora, New Mexico