Harshberger ; Plant formations of Nockamixon Rocks ()71 



Cy stopfer is fragilis, 

 Tradcscantia virgiiiiana^ 



Castilleja cocci nca^ 



Nepeta Glcchoma [N. hale raced), 



Coinmelina nudiflora [C. com- Leomtrifs Cardiaca^ 



munis). 



Euphorbia utaculata, 



it 



a 



Pre slit, 

 hirsnta, 

 Crotalaria sagittalis. 

 Cassia marilandica^ 

 * ' Chamaccrista, 



% 



a 



7itctitans, 



Laminin macidatiim, 

 Aster nudtijlorus^ 



" ditmostis 

 Eclipta alba^ 



HeleniuDi aiituuinale, 

 Mikania scandens, 



Solidago lanceolata [S. graviini- 

 folia). 



Lysimachia qiiadrifolia^ 



" Njtmmularia, 



Invading weed species : The original formations have been 

 disturbed but little by the invasion of weed species, because the 

 original vegetation has remained in possession of the rocks and 

 talus slopes and, therefore, the formations are closed ones in the 

 phytogeographic sense. The following species of foreign intro- 

 duction are elements which might strongly alter the existing for- 

 mations, if not held in check by the native vegetation. However, 

 it is important to recognize this element and enumerate the species 

 belonging to it. The species in small capitals were Introduced 

 by the early Pennsylvania German settlers, who cultivated them. 



Urtica dioica, 



HUxMULUS LUPULUS 



Riunex crispus^ 

 " obtusifolius, 



AcetoscIIa, 



Polygonum orientale, 



" Persic aria ^ 



Fagopvrum esculent um, 



Chenopoditim album, 



i( 



Botrys, 



Cerastium vulgatum, 

 Portnlaca olcracea, 

 Rajiuncidus bidbosus, 

 Helleborus niger (escaped), 

 Sisynibrivm officinale, 

 Brassica nigra, 

 Capsella Bursa-pastoris, 

 Lcpidium cauipcsire. 

 Pot cut ill a norvegica, ' 

 Trifolium arvense. 



A7naranthus retrojlexus, 

 Phytolacca decandra, 



Mollugo verticillata, 

 Dianthus Anneria, 



(t 



barbatus (established 



<< 



t€ 



a 



(i 



it 



pratense, 



REPENS, 



procuuibcns^ 



agrarium, 



jncarnatum, 



for years), 

 Saponaria officinalis. 

 Lychnis vespertina {L. alba), 

 Agrostcfnwa Githago^ 

 Stcllaria media. 



Melilotus alba, 



" officinalis, 

 Medicago saliva, 



LlNUM USFTATISSIMUM, 



Maha rotundifolia. 



