Harshberger : Plant fo{imations of Nockamixon Rocks 657 



the talus slope. The woody vines, or lianes, which form a part 

 of the Deciduous Forest Formation may be enumerated in the 

 order of their importance. 



Lianes : Ainpelopis qiiinquefolia, Rhus radicaus, Vitis Labntsca^ 



V, aestivalis^ V. cordifolia^ V. vidpina, Cclastrus scaitdens^ Clonatis 



virginiana, Menispermum canadense, Lonicera grata (Z. Capri- 



folijwi). Some of these ascend the rock faces, others reach the 



light by climbing the forest trees. 



Tree mosses : The following mosses and hepatics^ according to 

 Lydia P. Borden, occur on the trunks and projecting roots of the 

 forest trees. Near the base are found Geocalyx graveolens^ Lopho- 

 colea Jieterophylla^ Dicranella heteromalla^ BrytiDi roseuvi^ and, else- 

 where, Fi'tdlania eboracensis, Anomodon apiadattis^ A. ros trains, 



and A. att€7t7(atns. 



The forest floor is occupied by herbaceous plants which are 

 commonly associated with the broad-leaved forest trees through- 

 out the Piedmont Region. But it should be remarlced here, that 

 the numerical preponderance of certain of these herbs is to be ac- 

 counted for by the peculiar habitat surroundings, as well as by 

 the composition of the characteristic tree facies. 



Herbaceous species (fourth, or ground layer): The classifica- 

 tion of the herbaceous species of the forest is a difficult matter for 

 several methods might be adopted according to the viewpoint of 

 the observer. The following groups are adopted to arrange the 

 herbs in the formation under consideration : 



Abundant ferns : Dryopteris marginalis, Polystichum acrosti- 

 choides, Adiantum pedattun. Each of these ferns forms clumps on 

 the forest floor. The first two species remain green during winter, 

 while Adiantum pedatuvi is destroyed with the first sharp frost. 



>lypodium vulgare (abundant), Cystopt 

 Cainptosorns rhizophyUus (frequent 



Aspli 



ferns : Asplenimn ebeneum (A. platy neuron), Phegop- 

 te7'is hexag07ioptera^ Dennstaedtia pnnctilobida, Lycopodiiun clava- 

 inm, L. coniplanatum^ Botrychium obliqnum, B. virginiamun. 



Abundant herbs: Laportea canadensis, Impatiens fidva {I. 

 biflora), Polygonatuui biflorum, P. gigantenm {P, covimidatnui), 

 Sindacina racemosa, Asarum canadense, Mitella diphylla, Sangui- 



