Je. Mickle, CUTICULAR MICROMORPHOLOGY OF PAGIOPHYLLUM-BLADENENSIS, COMB-NOV, FROMTHE LATE CRETACEOUS OF THE NORTH-CAROLINA COASTAL-PLAIN, USA, Bulletin of the Torrey Botanical Club, 120(4), 1993, pp. 387-391
Abundant leaf and branch compressions referable Araucaria bladenensis
Berry have been recovered from Late Cretaceous gray mudstones of the T
ar Heel Formation along the Tar River in Pitt County, NC. Leaves are u
p to 21.2 mm long by 9.9 mm wide, flat, sessile, coriaceous, and fusif
orm, and have entire margins, acute tips, and numerous parallel, unbra
nched veins. Leaves are borne helically and are imbricate. Cuticle was
recovered using 20% CrO3 and is incompletely preserved. Epidermal cel
ls are irregular to rectangular in shape with thin, straight anticlina
l walls. Sunken stomata are in discontinuous rows with the long axis o
f guard cells typically parallel to that of the leaf Stomata are encyc
locytic with a surrounding ring of three to five encircling cells. Ext
ernal stomatal wax plugs are commonly present. Florin rings are presen
t but not observed consistently. Other stomatal features are indistinc
t due to incomplete preservation. Leaf morphology is similar to that s
een in Araucariaceae and in Nageia sect. Nageia de Laubenfels (Podocar
paceae). Among cuticular features, the presence of Florin rings is con
sistent 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 Arauc
ariaceae but does not fit precisely within any known taxa. Consequentl
y, A. bladenensis is transferred to the form-genus Pagiophyllum Heer a
s P. bladenensis comb. nov.