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Stratigraphic studies of pollen from an oxbow on a Holocene terrace and from an upland swale near the Tombigbee River in eastern Mississippi provide a record of Holocene vegetational changes. From -11,000 to 7300 years B.P. the forests were dominated by oaks and hickories. Mesic forest species were common, at least locally. This suggests the existence of a significant moisture gradient between central Miss.-Ala. and the vicinity of Goshen Springs (Delcourt, 1980) in southern Alabama. Mesic taxa declined markedly beginning at about 9000 years B.P. Between 7300 and 3500 years B.P., water levels in the oxbow dropped. Regional forests were dominated by oak and hickory, and mesic taxa became uncommon. Nyssa was extremely common between 2400 and 500 years B.P.; this probably included black gum in the uplands and both black gum and tupelo gum in wet lowland sites. A regional increase in pine is evident beginning at about 2400 years B.P. This pine expansion is eventually associated with decreases in oak; hickory and Nyssa. We suggest that aboriginal land use and an increased frequency of fires caused the latter forest changes. An increase in Ambrosia in the uppermost levels marks European settlement. At this time cypress, wetland herbs and shrubs, and Orontium colonized the oxbow, perhaps because of generally higher water levels due to decreased evapotranspiration caused by land clearance.

Six species of Pinguicula occurring in the southeastern United States are treated. P. ionantha Godfrey is newly described; it is restricted in its distribution to Franklin, Liberty, Gulf and Bay counties, all in the Panhandle of western Florida. A key to the species, descriptions and chromosome counts are included. All species are illustrated. Wood and Godfrey (1957) in a discussion of the Pinguiculas of the southeastern United States treated five species, four of which had previously been known from the area. P. primuliflora, there newly described, had been found to occur from southwestern Georgia and western Florida to southern Mississippi. In addition to the morphological features by which it was distinguished, P. primuliflora was noted to occur in habitats unusual for Pinguicula, namely, in shady areas of spring runs or springy places with Sphagnum or Pallavicinia, on grassy tussocks, bases of gum trees, and on mill timbers in association with Orontium or Nymphoides, almost always where there is flowing water. Some specimens were collected in moist, sandy soils in pinelands but these plants were less well-developed than those from wetter localities. It happens that specimens from the latter, different, type sites comprised two collections from pinelands in Franklin and Liberty counties, Florida, somewhat to the southeast of the more numerous localities for well-developed plants. During the wet spring of 1960, we visited Franklin and Liberty County localities and discovered well-developed populations of a Pinguicula clearly distinguishable from P. planifolia and unlike P. primuliflora to which species the earlier collections had been assigned. The plants were in shallow standing water of sandy-peaty pineland depressions and broad roadside drainage ditches. Populations of the same plant, again associated with P. planifolia, were subsequently located in Gulf and Bay counties, Florida, just to the west. This Pinguicula is newly named and described below. The total number of species now known for Florida and the southeastern United States iS siX. During the spring seasons of 1960 and 1961 a few plants of each of the six Pinguiculas were collected at several localities, the total being about a hundred plants. They were placed in shallow pans of water in the laboratory where they fourished, producing flowers 1 This investigation was supported (in part by a research grant, RG-6305, to the senior author from the Division of General Medical Sciences, Public Health Service.