Acer cf. saccharinum Linnaeus, 1753

Stults, DZ & Axsmith, BJ, 2015, New plant fossil records and paleoclimate analyses of the late Pliocene Citronelle Formation flora, U. S. Gulf Coast, Palaeontologia Electronica (New York, N. Y.: 1991) 2 (6), pp. 1-35 : 21

Acer cf. saccharinum Linnaeus, 1753

Figure 8.1

Description. Two partial mesophyllic leaves indicate a second Acer species from the Citronelle Formation similar to A. saccharinum . Inferring mostly bilateral symmetry of the lamina on either side of the midvein, the size of larger specimen extrapolates to a leaf> 8.7 cm long and 6.4 cm wide. Margins are toothed. Base is truncate. Apex is not preserved. Primary venation is actinodromous or palinactinodromous. Six suprabasal veins are present, as are agrophic compound veins. Both interior secondary veins and intersecondary veins are present. Tertiary veins are irregular reticulate. Teeth are of one order, but differ in size, some very large. Tooth sinuses are mostly rounded, teeth convex/straight proximally, concave/straight distally. Several teeth are present basally, which differentiates these specimens from A. saccharum . Additionally, they can be distinguished from the palmately lobed, palinactinodromous leaves of Platanus based upon the much broader tooth-width of Platanus leaves, and the greater incision of the lobes in Platanus leaves.

Site occurrence. Scarborough School.

Remarks. There are 27 species of Acer currently in the flora of North America, seven of which have been introduced. Nine of these species occur within the southeastern United States; seven of which, including A. saccharinum , are wetland inhabitants.

Figures

FIGURE 8. Representative Sapindaceae (continued), Smilicaceae, and Ulmaceae from the Citronelle Formation. 1. Acer cf. saccharinum partial leaf (UF 19315–062088), scale bar equals 1 cm. 2. Smilax sp. partial leaf (UF 19413– 062089), scale bar equals 5 mm. 3. Close-up of Figure 8.2 Smilax leaf showing higher order venation details, scale bar equals 2.5 mm. 4. Ulmus sp. leaf (UF 19413–062090), scale bar equals 5 mm. 5. Close-up of Figure 8.4 Ulmus leaf showing margin details and multiple orders of teeth, scale bar equals 2.5 mm.