42 MISSISSIPPI STATE GEOLOGICAL SURVEY [Bull. 
Arisaema dracontium Uvularia sessilifolia 
Osmunda regalis Boehmeria cylindrica 
Osmunda cinnamomea Medeola Virginica 
Adiantum pedatum Thalictrum purpurascens ? 
Habenaria ciliaris Elodea campanulata 
Platanthera bracteata i Galium trifidum 
Platanthera psychodes Dioclea Boykinii. 
Microstylis ophoioglosscides 
- 
In open marshy places and bordering or growing in the 
water of ponds and sluggish streams, the following are re- 
presentative : 
Eupatorum perfohatum Zygadenus glaberrimus 
Eupatorium rotundifolium Ranunculus pusillus 
Senecio lobatus Linaria Canadensis 
Physestegia Virginiana Typha latifolia 
Dulichium spathaceum Rhexia Mariana 
Sagittaria variabilis Rhexia Virginica 
Scirpus lacustris Ludwigia alternifolia 
Peltandra undulata Ludwigia palustris 
Hibiscus moscheutos Acorus calamus. 
Loess or Bluff Region—This region embraces a narrow 
strip from 15 to 20 miles wide bordering the eastern edge of 
the Delta lowlands from the northern boundaries of the state 
tc and beyond the line of Louisiana on the south. From Vicks- 
burg south the bluffs le close in towards the river, and are 
rather more pronounced than farther north. The bluff hills 
lie on or somewhat below the general level of the central pla- 
teau, which it borders on the west, the characteristic prccipi- 
tous hills of this region being remnants of the ragged edge of 
the intericr plateau produced by the deep eutting of streams 
in passing from the plateau level to that of the Delta lowlands. 
The marked broken and intricate character of the topo- 
graphy is due to a peculiarity of the material eroded. For 
15 or 20 miles back from the Delta edge a thick deposit of eal- 
careous loess silt overlies the surface to a depth of from 30 to 
79 feet, and forms the basis for the soil and for the peeuliay 
character of erosion into vertical faces. This loess is a fine 
