Salix sp.

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 : 20

Salix sp.

Figure 7.4–7.5

Description. Salix is identified from two oblong leaf fossils. A petiole is present on one specimen and is 8 mm long. The length of the complete specimen is 3.5 cm long and 1.3 cm wide, whereas an incomplete specimen is> 5.5 cm long with a width of 2 cm, L:W ratios approximately 3:1. Margin is unlobed, serrate. The bases are acute and slightly asymmetrical. The apex is preserved in one specimen and is acute and straight. Primary venation is pinnate. Secondary veins are semicraspedodromous, excurrent. Secondaries are noticeably arcuate near the basal end. Intersecondaries are present, but not prominent. Tertiary and quaternary veins are irregular reticulate. Teeth are of one order, present along the entire lamina. Teeth are small, regularly spaced, angular to rounded sinuses, convex/straight proximally, concave/ straight distally, apices glandular ( Figure 7.5 ).

Site occurrence. Scarborough School and Perdido Park.

Remarks. The genus Salix currently contains approximately 450 species worldwide, 113 of these occur in North America. Those occurring today in Alabama, Florida, and Georgia are S. caroliniana , S. eriocephala , S. floridana , S. humilis , and S. nigra . Reproductive specimens of Salix have been found in Eocene deposits of Wyoming and late Oligocene and early Miocene deposits of Alaska ( Hollick, 1936; Wing 1981; Collinson 1992). Leaves of Salix have been described from Eocene deposits in Wyoming, North Dakota, Colorado, and Utah, and from Miocene deposits in Oregon ( MacGinitie, 1969; Hickey, 1977; Wing, 1981; Collinson, 1992; Fields, 1996).

Figures

FIGURE 7. Representatives Rosaceae (continued), Salicaceae, Rutaceae, and Sapindaceae from the Citronelle Formation. 1. Extant Crataegus floridana from USAM herbarium for comparison with Figure 6. 7, scale bar equals 5 mm. 2. Rubus sp. leaf (UF 19413–062083), scale bar equals 5 mm. 3. Ptelea cf. trifoliata leaf (UF 19210– 062084), scale bar equals 5 mm. 4. Salix sp. leaf (UF 19210–062085), scale bar equals 1 cm. 5. Close-up of Figure 7.4 Salix leaf margin showing salicoid teeth, scale bar equals 2.5 mm. 6. Acer cf. rubrum basal portion of leaf (UF 19210–062087), scale bar equals 1 cm. 7. Acer cf. rubrum leaf (UF 19210–062086), scale bar equals 1 cm. 8. Extant Acer rubrum USAM herbarium for comparison with Figure 7.6–7, scale bar equals 1 cm.