No. 14.] FLOWERING PLANTS AND FERNS. 7 



plant activities, so that for special localities or seasons the condi- 

 tions require special consideration. Unless otherwise stated the 

 dates given in the Catalogue indicate the time when the plant is 

 usually in flower, or, for the ferns, when the spores are mature. 



The sign X preceding the name of a species indicates that it is 

 supposed to be of hybrid origin. 



All statements indicating the comparative frequency of occur- 

 rence of the species are to be considered in relation to allied 

 species and with direct reference to the habitat cited ; in other 

 situations the plant may not occur at all or exceptionally. A 

 plant " common " in its habitat should be sufficiently plentiful to 

 be within the observation of all who could recognize it, yet there 

 is a vast difference in the comparative numbers of most really 

 plentiful woody plants and low herbs of the same rating. " Fre- 

 quent, " too, is relative in the same sense. Although, as a rule, 

 frequent or common in the habitat and area cited, many such 

 plants may be rare in, or even absent from, certain intervals 

 where the conditions appear to be equally favorable. " Occa- 

 sional " needs no explanation. " Rare " is intended to apply to 

 those plants which appear to occur sparingly, usually in but few 

 localities as named. " Local " refers especially to such plants as 

 occur at one or more isolated or special areas, but are there 

 more or less plentiful, as indicated by the context. 



The habitats cited are those observed in Connecticut, and 

 although often variable are expressive of local conditions. 



In accordance with the spirit of the Act incorporating the 

 Survey, due attention has been given to the economic features of 

 the various species, when required, in notes appended to each. 

 Although in some respects desirable, it seems, on the whole, inad- 

 visable at this time to enter upon a discussion of the associations 

 of native plants and the probable causes leading to such congrega- 

 tions. It is necessary to collect much more complete data than 

 are now available before such discussion can be profitably taken 

 up. Mere lists of such plant aggregates are apt to be of no value 

 to most readers and of little utility to practical botanists. 



It is a pleasure to acknowledge the assistance of all who have 

 contributed items of information toward the completeness of 

 this Catalogue and whose names appear throughout the work. 

 Particular mention should be made of Dr. B. L. Robinson and 

 Prof. M. L. Fernald, of the Gray Herbarium of Harvard Uni- 



