INTRoDI ( ri(JN. XV 



unusual in our region may be mentioned Cardamine pratensis, 

 Ptelea trifolia, Staphylea trifoltata, Celtis occidentalis. Wood- 

 war dia Virginica, Lygodiurn pabnatum and Pierospora An- 

 dromedea. 



Introduced Plants. Aside from the regular list of intro- 

 duced species which have made their way into many parts of 

 America and become so much at home that they appear as if na- 

 tive, our region furnishes some of so recent introduction that the 

 process of naturalization may be said to be still going on. Good 

 examples of this are found in Trifoliion hybridiim, Hesperis 

 matronalts, Scabiosa australis, Hieracium auraniiacutn, H. 

 pHosella, Tragopogon pratttisis, Cichoriutn Intybics, Lactuca 

 Scariola, Cuscuta Epithyminn, Echium viilgare, Solanum ros- 

 trattim. Euphorbia Niceccnsis, E. peplus and Iris pseudacorus. 



THE LESSER FLORAS. 



Not the least interesting feature of our region is found in the 

 natural grouping of plants into lesser floras. Peculiar conditions 

 of soil, temperature or topography serve to limit these areas and 

 in many cases the lines are decidedly marked. Some of the more 

 important are given herewith 



Pond Brook. This name is applied to two small lakes lying 

 in the valley of the Chenango, about two miles south of its junc- 

 tion with the Tioughnioga. In a general way it is also applied 

 to the whole of the surrounding region, whose surface is here 

 most peculiar, consisting of a series of great depressions separated 

 from one another by low, steep banks of glacial debris. The re- 

 gion probably dates its present formation from the retreat of the 

 ice-sheet. Two of the depressions hold the lakes, whose bottoms 

 are scarcely above the level of the river, and the rest contain peat- 

 bogs overgrown with sphagnum. This region is probably richer 

 in species than any other place of like extent within our limits. 

 Not to mention commoner things, it contains Drosera rotundi- 

 foliay Sarracenia purpurea, Nymphcca advend, Decodon verti- 

 cillatiis^ Cardamine pratensis, Castalia odor at a, Naumburgia 

 thyrsijlora, Cladiicm mariscoides, Utricularia vulgaris, Ba- 

 trachiu))i trichophylluni, Rytichospora alba, Eriophorum poly- 

 stachyon, Scheuchzeria palustris, Cinna arundinacea, Chiogenes 

 hispidiila. Azalea canescens^ A. nudifiora. Lobelia Kabnii, Cyp- 

 ripediiDu hirsutum, C. acaule, Comarum palustre, Atragene 



