GENEEAL ASPECT OF THE FLORA. 17 



rises about 200 feet over the floods of the Mississipj)!. The east- 

 ern portion of this area is conipo ed of cretaceous and the western 

 of tertiery and ]-ost-tertiery deposits, either sands or soft creta- 

 ceous shale. Folid, often ferruginous, sandstones appear at the 

 surface, scattered in incoherent masses. 



We behold no longer limpid strtams, rippling over rocky bot- 

 toms, sided by cliffs and bluffs. Instead of them we find lagoons 

 and swampy borders, stretching along muddy-looking waters of 

 sluggish streams. 



From distance already, before crossing the river, we are in 

 sight of towering cypresses. While a thousand miles east from 

 here they yet occupy the shore-line of the Atlantic, here the 

 shore line has receded to the Gulf and left the cypress behind. 

 Their dimensions are truly enormous. The far spreading roots 

 emerge like sharp-backed ridges from the brownish lagoon, grad- 

 ually creeping up and girding with buttress-like projections the 

 many-angled column. A perpendicular shaft ascends to a height 

 of 120-150 feet and then spreads a flat or hemispherical crown. 

 Such I liave seen twenty years ago near Johnsonville. Cypress 

 swamps are along both big rivers, and many other extensive 

 swamps and swampy lands are along every watercourse, the most 

 perhaps along Big Sandy. It may therefore be expected that a 

 great many more aquatic species and such as inhabit marshy 

 lauds exist in this region, than in either East or Middle Tennes- 

 see. My own experience is, however, limited and restricted to 

 one point on the Mississippi river, the regions of Brownsville, 

 Humbolt, McKenzie, Hollow-rock and Johnsonville, in which 

 places I have made interesting collections. 



PLANTS PECULIAR TO WEST TENNESSEE. 



Ranunculus multilidus Pursh. Planera iiquatica Gmel. 



Brasenia peltata Pursh. Lithospermum a nguisti folium 

 Cabomba Caroliniana Gray. INIichx. 



Hypericum lobocarpuni Gattinger. Utricularia biflora Lam. 



Gleditschia monosperma Walt. Iris cuprea Pursh. 



Dalea alopecuroides Willd. Iris hexagona Walt. 



Berchemia volubilis DG. Habenaria virescens Sprengel. 



Galium Arkansanum Gray. Juncus mititaris Bigel. 



Eryngiuni prostratum Nutt. Scirpus debilis Pursh. 



Marshallia lanceolata Pursh. ZizMuia aquatica L. 



Ambrosia bidentata Michx. Sp^rtina cynosuroides Willd. 



Helenium tennifolium Nutt. Eragrostis oxylepis Torr. 



Senecio lobatus Pers. Cenrhrus tribuloides L. 



Hydrolea affinis Gray. Aristida ramosissima Engelm. 



Verbena stricta Vent. Taxodium distichum Rich. 

 Limnanthemumlacunosum Griese. Asplenium Filix femina L. var, 

 Polypremum procumbens L. anaustum Gray. 



Quercus bicolor Willd. Azolla Caroliniana Willd. 



Stillingia sylvatica L. Equif etum robustum R. Br, 



