CHARACTEES HABIT 7 



times are by Oliver, who determined the Mexican and Central American 

 collections of Liebmann and Oersted ; by Eichler, who took note of extra- 

 territorial forms when revising the Loranthaceae of Brazil; and by 

 Urban, who rendered a similar service in connection with his study of 

 the family as represented in the West Indies. 



ANALYSIS OF CHARACTERS 



A few contrasts may make evident some of the differences between 

 species in this genus which may be accepted as characters in their tax- 

 onomy. The partial or complete neglect of these characters, to the pref- 

 erence of the more usually employed differences in shape of foliage, 

 etc., explains the insufficiency of such earlier treatment as that of the 

 elder de Candolle in his very clean-cut elaboration of Viscum in the 

 Prodromus, in 1830, and accounts for the confusion of our own species 

 by the usually very accurate and acute Engelmann; and their tacit or 

 explicit recognition underlies the masterly work of Eichler and Urban 

 in revisions respectively of Brazilian and West Indian forms. That 

 these differences have been neglected so generally depends rather on 

 their seeming insignificance than on difficulty in seeing them. 



COLOR. How generally the color of normally vegetating mistletoes 

 offers differential characters remains to be recorded. As is true of all 

 of the species of the related genus Arceuthobium or Razoumofskya, a 

 number of the species of Phoradendron that grow on conifers, e. g. P. 

 juniperinum, P. densum, etc.,' are of an olive or brownish shade, the 

 West Indian P. flavens gets its name from a very striking yellow color- 

 ation, and some of the mistletoes that reach our market at Christmas 

 time, e. g. P. macrophyllum, possess a very beautiful golden coloring, 

 perhaps as the result of a partial etiolation after collection; but the 

 prevailing color appears to be green, more or less dulled or shaded by a 

 tinge of gray or olive. 



HABIT. No doubt personal familiarity in the field with the different 

 species of Plwradendron will reveal several differences in aspect that 

 cannot now be used in their characterization, for even limited acquaint- 

 ance with them in nature shows that they are far from uniform in 

 habit of growth. For the present, however, it can be said only that in 

 this respect most species of Phoradendron resemble the common Euro- 

 pean Viscum in their bunched tufts, so that a winter picture of either 

 may easily be mistaken for that of the other (PI. 1). A marked excep- 

 tion is found in some of the desert mistletoes, like P. calif ornicum and 

 P, Libocedri (PI. 2), which when seen from a distance sometimes suggest 

 the cactus genus Rhipsalis in their long pendent tufts : and the Mexican 

 P. calyculatum and a few other species form wide-spreading fountain- 

 like masses of still greater size. 



