Ilex 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 : 7

Ilex sp.

Figure 2.1

Description. One simple, petiolate leaf is attributed to Ilex . Petiole attachment is marginal. The blade is a notophyll (4 cm long, 1.8 cm wide), shape ovate, symmetrical with a L:W ratio 2:1. The margin is unlobed, serrate. The base is acute, straight, symmetrical. The apex is acute, straight, the terminal apex possibly retuse (as occurs in some extant Ilex species such as I. decidua and I. coricea ). Primary vein framework pinnate. Two basal veins are present. The secondary vein framework is mixed craspedodromous and semicraspedodromous. Secondaries are irregularly spaced, excurrent, and arcuate. Tertiary, quaternary, and quinternary veins are more difficult to characterize probably because the leaf was coriaceous, however, they appear to be irregular reticulate. Teeth are small, of a single order, regularly spaced, 6–8 per cm. Sinuses are angular. Teeth are straight/convex proximally, straight distally, apices spinose.

Site Occurrence. Perdido Park.

Remarks. Of the 35 native species of Ilex in the United States, approximately 40% occur within the southeast. Ilex is first documented in the Late Cretaceous; however, the common ancestor of all modern Ilex species has been estimated as Miocene as the most basal lineages of the genus were extinct by that time ( Manen et al., 2010). In North America, Ilex seeds have been described from the early Miocene Brandon Lignite of Vermont (Tiffney, 1977).

Figures

FIGURE 2. Representative Aquifoliaceae through Juglandaceae from the Citronelle Formation. 1. Ilex sp. leaf (UF 19210–062063), scale bar equals 5 mm. 2. Clethra cf. alnifolia (UF 19210–062064) partial leaf, arrow indicates mucronate tooth apex, scale bar equals 5 mm. 3. Close-up of Figure 2.2 Clethra leaf, note mixed-percurrent tertiaries, scale bar equals 2.5 mm. 4. Extant Clethra alnifolia leaf from USAM herbarium for comparison with Figure 2.2, scale bar equals 5 mm. 5. Gaylussacia sp. leaf (UF 19315–062065), scale bar equals 5 mm. 6. Extant Gaylussacia sp. from USAM herbarium for comparison with Figure 2.5, scale bar equals 5 mm. 7. Vaccinium sp. leaf (UF 19315–062066), scale bar equals 5 mm. 8. Close-up of Vaccinium leaf margin from Figure 2.7 showing teeth, scale bar equals 2.5 mm. 9. Carya fruit (UF 19315 – 062068), scale bar equals 5 mm. 10. Carya sp. catkin with in situ pollen (UF 19315 – 062067), scale bar equals 5 mm. 11. Carya sp. pollen tetrad from specimen in Figure 2.10, scale bar equals 10 µm.