236 JOURNAL OF THE ARNOLD ARBORETUM [vol. t 



general cliaracter of its vegetation let us return to tlie u]>per canyons of the 

 perennial streams where most pecuUar conditions exist and many surprising 

 and perplexing plants are found. Here the scenery is often most pictur- 

 esque: The high limestone cliffs in places rise as sheer walls but oflener as 

 a series of terraces, green with shrubs and herbage where tliere is seeping 

 water; promontories and peaks are carved into most fantastic shapes by 

 ages of erosion, and great castle-like masses detached perliaps centuries 

 ago from the face of the clilf stand out amongst the snuillcr rubble on 

 the floor of the canyon. Xerophytic ferns, Columbines, Scarlet Sage, 

 shrubby Eupatoriums, Buddleas or the yellow-flowered Laphamia grow 

 abundantly from clefts in the rocks, sometimes where scarcely a trace of 

 soil or foothold is apparent. Along some of the ledges water is constantly 

 seeping and strong springs gush out here and there, constantly augmenting 

 the stream which dashes and foams below over its rocky bed. At frequent 

 intervals it descends over outstanding ledges, forming small cascades, and 

 often beloAV them broadens out into deep, limpid pools, favorite haunts of 

 the black bass and where the wild deer are still sometimes mirrored as they 

 come down to drink. Farther down, the stream may disappear entirely 

 under the loose gravel and rubble only to emerge again as a lower ledge 

 conies to the surface. Under overhanging ledges, kept wet by seepage 

 water, the Venus' Hair Fern (Adiantum Capillus-Venerls) grows luxuri- 

 antly and the Sword Fern {Dryoptcris normalis) is found along tlic rocky 

 margins of the pools. 



Many of tlte w^oody plants common over the more open parts of the 

 plateau here attain their maximum development and l>ccome truly ar1)or- 

 escent. Such species as the Mountain Cedar, Ilackberry, Cedar Elm, 

 Pecan, Laccy's Oak, Shin Oak, Soapberry and Mexican Mullx^rry form a 

 large proportion of the forest growth. But in a few favored spots, where 

 water is abundant and tlie canyon well protected by high bluffs from the 

 parching winds and direct sunlight during the hottest part of the day, small 

 colonics of plants arc found of species identical with or closely allied to 



those of the Atlantic or Gulf coastal plain forest and quite foreign to the 



general flora of this region. Besides the Cypress, which we found lower 

 down in the open canyons, such trees as Slippery Elm, Bur Oak, Chestnut 

 Oak, Wild Cherry, Sugar Maple and three or four forms of Linden attain a 

 considerable size; while amongst smaller growth there are Yellow and Red- 

 flowered Buckeye, Deciduous Holly, French Mulberry (Calycarpum ameri- 

 canum)y Indian Cherry {Rhamnus caroliniana) ^ Spice-bush and several 

 species of red Haws. Herbaceous species associated with them include the 

 Rattlesnake Fern {BotrycJiium nrginianitm). Coral-root Orchid, Virginian 

 Snake-root and two or three kinds of Violet. Where the stream approaches 

 the high bluffs with north or east exposure and with only room for a narrow 

 strip of talus and rich soil between them, ideal conditions for these peculiar 

 colonies are found. Some of the rarer species are limited to such situa- 

 tions, and while others mentioned above are by no means rare nearly all 

 are confined to the protected canyons. 



