4 THE GENUS PHOEADENDRON 



then into classified form, that on an average nearly two new named forms 

 appeared for each one already admitted to our northern flora. 



Notwithstanding an intention to limit my investigation to the species 

 of continental North America, the temptation to learn the characters of 

 the South American species proved irresistible when, at Brussels, I 

 examined the material in the personal herbarium of von Martius, whose 

 collections have done so much to make known the flora of Brazil; and 

 it was not long before the genus as a whole engaged my interest, though 

 West Indian material was given less attention than the other until at 

 Dahlem I reached the collection of Professor Urban, who in 1897 had 

 published a revision of all of the West Indian Loranthaceae. To my keen 

 satisfaction, I then found that for the Antillean region very few forms 

 were to be differentiated from those admitted by Urban, confirming my 

 judgment that the large increase in our own flora rests rather upon 

 previous neglect of application to them of characters which appear to 

 be really differential, than on excessive optimism on my own part con- 

 cerning their separability. The thorough study of tropical forms by 

 Eichler in his revision of Loranthaceae for the Flora Brasiliensis, in 

 1868, supplemented by a reelaboration of available material when Urban 

 monographed the West Indian forms, has also prevented an increase in 

 the number of South American species at all comparable with that 

 within our own region, though the number of names added is relatively 

 greater than for the Antilles. The general results of the study as now 

 published were laid before the Chicago meeting of the National Acad- 

 emy in 1915, and printed in brief form in the initial number of the 

 Proceedings of the Academy.* 



NOMENCLATURE 



In the following treatment, synonymy has been confined to citation 

 of the original publication of each species and of its synonyms, except 

 for its inclusion in either of the classic publications on the genus and 

 for reference to all published illustrations. No effort has been made to 

 rectify the frequent use of inapplicable or inaccurate names in refer- 

 ences to the plants in periodical literature, or in the earlier floras before 

 Viscum and Phoradendron were differentiated, except in a very few 

 cases where more than one species was clearly referred to under a new 

 name. To anyone needing to make corrections, the way is rendered 

 comparatively clear by the full citation of localities and collectors which 

 follows the description of each species. 



The names employed for the plants are intended to be conformed 

 to the international rules adopted by the Vienna Congress of 1905 



*Trelease. W. Phoradendron. Proe. Nat. Acad. Sci. vol. 1. p. 30-35. Jan. 1915. 



