Cuticular Micromorphology of Pagiophyllum bladenensis, Comb. nov., from the Late Cretaceous of the North Carolina Coastal Plain, U. S. A.

Abstract

MICKLE, J. E. (Department of Botany, North Carolina State University, Box 7612, Raleigh, NC 27695). Cuticular micromorphology of Pagiophyllum bladenensis, comb. nov., from the Late Cretaceous of the North Carolina Coastal Plain, U.S.A. Bull. Torrey Bot. Club 120: 387391.1993-Abundant leafand branch compressions referable Araucaria bladenensis Berry have been recovered from Late Cretaceous gray mudstones of the Tar Heel Formation along the Tar River in Pitt County, NC. Leaves are up to 21.2 mm long by 9.9 mm wide, flat, sessile, coriaceous, and fusiform, and have entire margins, acute tips, and numerous parallel, unbranched veins. Leaves are borne helically and are imbricate. Cuticle was recovered using 20% CrO3 and is incompletely preserved. Epidermal cells are irregular to rectangular in shape with thin, straight anticlinal walls. Sunken stomata are in discontinuous rows with the long axis of guard cells typically parallel to that of the leaf. Stomata are encyclocytic with a surrounding ring of three to five encircling cells. External stomatal wax plugs are commonly present. Florin rings are present but not observed consistently. Other stomatal features are indistinct due to incomplete preservation. Leaf morphology is similar to that seen in Araucariaceae and in Nageia sect. Nageia de Laubenfels (Podocarpaceae). Among cuticular features, the presence of Florin rings is consistent with Agathis Salisbury (Araucariaceae) and Podocarpaceae, and encircling cells are common in Araucariaceae and other conifers. It is concluded that this material shows its greatest affinities with Araucariaceae but does not fit precisely within any known taxa. Consequently, A. bladenensis is transferred to the form-genus Pagiophyllum Heer as P. bladenensis comb. nov.