Sassafras albidum ( Nuttal, 1818 ) Nees von Esenbeck, 1836

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 : 12-14

Sassafras albidum ( Nuttal, 1818) Nees von Esenbeck, 1836

Figure 4.4

Description. One bilobed leaf is attributed to Sassafras albidum . The overall outline is ovate with one lateral lobe. The original leaf was> 7 cm long. The main lobe has a width of 3 cm, whereas the lateral lobe is 1.5 cm wide. The base is missing. The apex of the central lobe is missing, but was probably rounded or acute. The apex of the lateral lobe is acute. It is difficult to categorize the primary venation, since the major veins to the lobes often do not diverge at the same point in other extant and fossil Sassafras specimens. The majority of S. albidum leaves are suprabasalactinodromous regardless of the number of lobes (usually from 1– 3) (personal observation). In the Citronelle Formation fossil, the primary vein of the lateral lobe is smaller than the primary vein in the main lobe. Secondary veins are brochidodromous, forming long arches departing the midvein at angles of approximately 50–55°. There are many intersecondary veins perpendicular to the midvein in the basal half of the leaf, becoming parallel to the major secondaries in the apical portion. Tertiary veins are mixed percurrent. Quaternary veins are irregular reticulate. A fimbrial vein is evident.

Site occurrence. Perdido Park.

Remarks. There are only two or three modern species of Sassafras , S. albidum being the only species currently in North America. It has a wide distribution over much of the eastern portion of the continent. Sassafras albidum probably diverged from Asian counterparts in the middle Miocene ( Chanderbali et al., 2001; Nie et al., 2008). Fossils of Sassafras have been reported from the western Miocene Clarkia and Succor Creek floras ( Smiley and Rember, 1985; Fields, 1996).

Figures

FIGURE 4. Representative Lauraceae from the Citronelle Formation. 1. Lindera sp. leaf (UF 19210–062072), scale bar equals 1 cm. 2. Extant Lindera leaf from USAM herbarium for comparison with Figure 4.1, scale bar equals 1 cm. 3. Persea sp. leaf (UF 19210–062073), scale bar equals 1 cm. 4. Sassafras albidum leaf (UF 19210–062074), scale bar equals 1 cm. 5. Close-up of Figure 4.1 Lindera leaf showing high order venation, scale bar equals 2.5 mm. 6. Close-up of Figure 4.3 Persea leaf showing high order venation, scale bar equals 2.5 mm.