'['^' 



25 GENERAL INTRODUCTION. 



Many plants that arc quite characteristic of northern latitudes are 

 found in greater or less abundance in isolated localities, such as high 

 mountain sides and cool shaded ravines or deep swamps, for south- 5 



ward of their usual homes; and, on the other hand, representatives of 'jf 



many southern species find their way far northward along suitable 

 water-courses, and warm valleys, that penetrate regions clothed in S 



vegetation of a very different type. These seeming peculiarities of 

 distribution are dependent on definite physiographical conditions 

 and are not difficult of explanation, however annoying they may be to 

 those engaged in the determination of distributional areas. Never- 

 theless there are species that are more or less distinctive of certain ^ 

 tolerably well-defined areas, and I present the following as a pro- 

 visional list, fairly characteristic of a Canadian Flora : Raminadtis 

 fiammula rcptaiis, Coptis trifolia, Diccntra Canadaisis, Viola rohmdi- 

 folia, V. Canadensis, Arcnaria Gra^idandica, Clayton ia Caroliniana, Gc- 

 raniiim Robertiamim Jmpati ens pallida , Oxalisacefosella, Acer spicatwn, 

 Polygala paucifolia, Potcrinni Canadense, GenniviacropJiylluniy Wald- 

 steinia fragarioides, Potent ilia tridentata, Dalabarda repefis, Ribes 

 lacustre, Mitella dip/iylla, M. nuda, Tiarella cordifolia, Epilobinm al- 

 pinntn, E. paliistre lineare, Circea alpina, Aralia trifolia, Cornus 

 Canadensis, Li7ineea boreal is, Aster acnniinatns, Solidago thyrsoidea, 

 S. Virga-aiirca alpina, Nalndus nanns, AL Boottii, Ca7?ipa7iida 

 rotnndifolia, Vaccineum nliginosiini, V. ccespitosnm, V. Vitis-Ideca, 

 ChiogencsJiispidula, Cassiope hypnoides (Dr. Parry), Cassandra calycn- 

 lata, Kabnia glanca, RJwdodendron iMpponicum, RJwdora Cafiadensis, 

 Ledum latifoliuni, Pyrola rotnndifolia, CliiniapJiila nmbellata, Trien- 

 talis Americana, Empetrnm nigrum, Jktulaglandnlosa, Salix Cutleri, 

 Pinus strobus, Abies nigra, A. Ca?iadensis, A. balsamea, Thuja occi- 

 dentalis, Diapensia Lapponica, Orchis spectabilis, Habenaria hypcr- 

 borea, H. dilitata, Goodyera repens, Listera cordata, Microstylis viono- 

 phyllos, Cypripedium pidKscens, C spec tab He, C. acaule, Trillium gran- 

 diflorum, T. erectum, T. erythrocarpum, Streptopus roseus, Clinto?iia 

 boreal is, Smilacena trifolia, S. bifolia. 



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