38* THE PLANT LIFE OF MARYLAND 



ber of occurrences are based on the collections or creditable authority 

 of several amateurs of Baltimore and Washington. The writer's 

 numbers have been mostly determined at the United States National 

 Herbarium, to the Curator and members of which grateful thanks 

 are here returned. All of the collections made are deposited either 

 at the National Herbarium or at the Herbarium of the Maryland 

 Agricultural College at College Park. The collections of the writer 

 are indicated by field numbers, those of others by the name of the 

 person in whose herbarium the plant may be sought, or upon whose 

 authority it is given. The writer wishes to express here his appre- 

 ciation of the interest and aid of Eobert K. Miller, without whose 

 assistance the List would have lacked much of its present value. 



The sequence and nomenclature follow Britton and Brown's Illus- 

 trated Flora of the Northern States and Canada (New York, 1897). 

 The common names given are usually those of the above Flora, or 

 else such as are in much more common use in Maryland. The state- 

 ments in regard to range within the State are based on the observa- 

 tions of the writer and his collaborators and on such collections and 

 literature as have been available. It is manifestly difficult to be 

 sure that a particular plant is absent from a given area, and it is 

 entirely within probability that many plants not now known from 

 the Coastal Zone in Maryland will be found there. It is even more 

 probable that many plants whose range is given as Coastal and Mid- 

 land Zones will be found in the Mountain Zone when its flora is 

 worked up, and indeed it may be taken that the writer is not rea- 

 sonably sure of the absence of a plant from the Mountain Zone unless 

 it is so stated. The habitat of each species is sometimes stated in the 

 definite terminology of the descriptive text, or in the case of more 

 ubiquitous plants is stated in very general terms. The profound dis- 

 turbance of the natural conditions for plants in the State has made 

 a more precise statement as to habitat impossible in the majority of 

 cases. The frequency, which is at best a subjective matter, is ex- 

 pressed in only four terms, — common, frequent, infrequent, rare, 

 and these always refer to the abundance of the plant in the particular 

 habitats in which it is found. 



The List includes 69 species, the occurrence of which in Maryland 

 is beyond the limits given for them in Britton's Manual of the Flora 



