Tennesskk Flora. 25 



the Mississippi Kiver and terminates there in another bluff, which 

 rises about 200 feet over the floods of the Mississippi. The eastern 

 portion of this area is composed of cretaceous deposits, and the 

 western portion is composed of tertiary and post-tertiary deposits,- 

 either sands or soft cretaceous shale. Solid, often ferruginous^ 

 sandstones appear at the surface, scattered in incoherent masses. 



We behold no longer limpid streams, 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 Tennessee Eiver, 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, gradually creep- 

 ing up and girding with buttresslike projections the many-angled 

 column. A perpendicular shaft ascends to a height of from 120 to 

 150 feet and then spreads in a flat or hemispherical crown. Such I 

 have seen, in 1864-70, near Johnsonville. Cypress swamps are- 

 along both big rivers, and many other extensive swamps and 

 swampy lands are along every water course — the most, perhaps, 

 along Big Sandy. It may, therefore, be expected that a great many 

 more aquatic species and such as inhabit marshy lands exist in this 

 region than in either East or Middle Tennessee. My own exi>eri- 

 ence is, however, limited and restricted to one point on the Missis- 

 sippi River — the regions of Brownsville, Humboldt, McKenzie, 

 Hollow Rock, and Johnsonville, in which places I have made inter- 

 esting collections. 



In the cypress swamps and boggy lowlands we find the planer 

 tree, or water elm {Planera aquatica\; the cypress (Taxodium dis- 

 tichum), the stateliest of our timber trees; the swamp locust {Gle- 

 ditschia monosperma) ; the tupelo gums (Nyssa sijlvatica and 

 Nyssa aquatica) ; the mountain sweet pepper bush (CUthra acumi- 

 nata), so frequent in the mountains of East Tennessee, but rare 

 in Middle and West Tennessee; the swamp white oak (Quercus 

 hicolor), the black alder {Ilex verticillata) , the swamp holly {Ilex 

 decidua), intertwined with the climbing bittersweet (Celastrus 

 scandens), and the supple-jack {Berchemia voluhilis). Two buck- 

 thorns {Rhamnus Carolmiana and Rhamnus lanceolata) are also 



