4 THE GENUS PHORADENDRON 
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 
ot 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- 
. €nees to the plants in periodical literature, or in the earlier floras before 
Viscum and Phoradendron were differentiated, except in a very few 
eases where more than one species was clearly referred to under a new 
name. То 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. Sei. vol. 1. p. 30-35. Jan. 1915. 
