Prince Salm 



Nov. 22,1855 



numbers only))belong to Op.lanigera , albicans » , macrorhlza , serica ;: 



and the Op. cyllndraceae are alll or Op.gracill s,or arborescens (at 



leat it looks that way) . This year f s seed plants are still too smalll 



to be able to say anything? only, with Op. fragllis a great simila- 



rity wlthf clavata is evident,*. The greatest difficulty, if one talks 



about the subdi Vision of a numerous genus as Opuntla , remains the 



to determine 



roaintenance of the natural affinities r , and j the best-possible se - 

 quence of the groups. . The structure of the seed, the form of the 



embryoo, with more or less albumen, can be accepted as an essentiali 

 characteristic and as a main charactei% if t after continued exami' - 

 nation, ,it proves correct, and if it is connected to a specific plant 

 form. I would not know,what other characteristic to propose except 

 the articulated or non-articulated shape of the stem, whicft, untill 

 now, mentioned by the way, , would rather coincide with the shape of 

 the seedl The shape of the members (branches ? E.D.) varies a lot? f , 

 and you do not have in your area any Speeles, which belong to my sec- 

 tion \ Platyacantae and Glomeratae. You also miss the Cruclatae,, 

 the Pa^adoxae, and a part of the Cylandraceae, and even the Elipti - 

 eae, which all must find their place in the strueture of the genus.. 

 Thejnembers are applanati In the ^ cruclatae and ellipticae; compressl 

 in the first half of the Dlvarlcatae ; globosi , oviformes, or eueumeri- 

 f ormes in the Platyacantae and Glomeratae ; cylindrici or clavati' 

 in the section Cylandr aceae; and finally( las if Nature made a joke 

 in destroying all our artificial characteristics) ) one finds in the 

 section ^ Paradoxa e a totally woody stenr, covered with a brown,, in- 

 cised bark, which carries the thinnest members of the entire genus:: 

 This species, which grows in Brasil forms the transltion to the gen- 

 us Pelrescia. . 



Hy the way, California, New Mexico and Texas are territoriesr 

 rieh in cacti and Opuntias.. 



