2 CKNKRAL 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, 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 valleys, 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 : Ranunculus 

 ftammula rcptans, Copt is trifolia, Di centra Canadensis, Viola rotundi- 

 folia, V. Canadensis, Arcuaria Grcenlandica, Claytonia Caroliniana, Ge- 

 ranium Robertianum, Impatienspallida,Oxalisacetosella, Accrspicatum, 

 Polygala paucifolia, Potcriuni Canadense, Gcum macropJiyllum, IVald- 

 stcinia fragarioides, Potentilla tridentata, Dalabarda rcpcns, Ribcs 

 lacustre, Jlfitclla dipliylla, J\f. nuda, Tiarclla cordifolia, Epilobium al- 

 pi/unji, E. palustrc lincarc, Circea alpina, Aral/a tri folia, Conius 

 Canadensis, Liniicca borealis, Aster acuininatus, Solidago tkyrsoidea, 

 S. Virga-aurea alpina, Nabulus nauus, N. Boottii, Campanula 

 rotundifolm, Vaccnienin uliginosuni, I r . wspitosinn-, V. Vitis-Idcca, 

 Chiogenes hispidula, Cassiope Jiypnoides (Dr. Parry), Cassandra calycu- 

 lata, Kalmia glauca, Rhododendron Lapponicum, Rhodora Canadensis, 

 Lcduui latifolium, Pyrola rotundifolia, ChimapJiila umbcllata, Tricn- 

 talis Americana, limpet nun nigrum, Betula glandulosa, Salix Cutler i, 

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

 dental is, Diapensia Lapponica, Orchis spectabilis, Habenaria Jiyper- 

 borca, H. d Hi tat a, Goodycra repens, Lister a cor data, Microstylis mono- 

 pliyllos, Cypripcdium pubescens, C. spectabile, C.acaule, Trillium gran- 

 diflorum, T. erectum, T. erytJirocarpum, Streptopus roseus, Clintonia 

 borealis, Smilacena trifolia, S. bifolia. 



