25 GENERAL INTRODUCTION. 



Many jilants 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, far south- 

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

 many southern species find their way far northward along suitable 

 water-courses, and warm x'alleys, that penetrate regions clothed in 

 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 : Raimncuhcs 

 flamiinila rcptaiis, Copfis trifolia, Diccnira Canadensis, I'iola rotnndi- 

 folia, ]\ Canadensis, Arenaria Greenlandiea, Claytonia Carol iniatia, Ge- 

 raninni Roberiianiiin, Inipatiens pallida, Oxalisacetosella, Acerspicatnni, 

 Polygala pancifolia, Potcritun Canadcnse, Geitvi niacropliyllum, Wald- 

 steinia fragarioidcs, Potentilla tridcntata, Dalabarda repens, Ribcs 

 laenstre, Mitclla diphylla, M. nuda, Tiarclla cordifolia, Epilobiuni al- 

 pininn, E. palustrc lineare, Circca alpina, Aralia trifolia, Cormis 

 Canadensis, Linncca borealis. Aster aenniinahts, Solidago t/iyrsoidea, 

 S. Virga-anrea alpina, Nabnhis nanus, JV. Boottii, Cantpamda 

 rotundifolia, Caecinaun nliginosiini, V. ccpspiiosnni, V. lltis-Idcea, 

 Chiogenes hispidiila, Cassiope hypnoides (Dr. Parry), Cassandra calycii- 

 lala, Kahnia glanea. Rhododendron Lapponicnni, Rkodora Canadensis, 

 Lcdnni latifoliuni, Pyrola rotundifolia, Chiniapliila nmbcllata , Trien- 

 talis Americana, Rnpeti-mn nigrnni, Betnla glandjilosa, Salix Cnileri, 

 Pinus strobiis, Abies nigra, A. Canadensis, A. balsamea, Thuja occi- 

 dentalis, Diapensia Lapponica, Orchis spcctabilis, Habenaria hyper- 

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

 phyllos, Cypripedinni pubescens, C. spectabile, C.acaule, Trilliuni gran- 

 dijtoruni, T. erectnni, T. erythrocaipuin, Strcptopus roseus-, Clintonia 

 borealis, Sniilacena trijolia, S. bifolia. 



