3 



What do you think of this flower and its affinities? Must she after all be included in 

 the group of the Echinocereusl Or does she have to get together with her compatriot from 

 Montevideo, Pfeiffera cerciformis which in my opinion was unfoitunately compared to 

 the Phillocactus et minor. (To help you in the comparison I also send you 



flowers of the Pfeiffera). From the beginning of this year I studied and analyzed all the 

 flowers of the Cereus that I possibly could procure. I was exposed to them and therefore 

 learned about the manner in which the stamen are habitually inserted. I wanted to know if 

 the Separation of the stamen in 2 series ( one inside the tube, the other attached circularly 

 around the neck in the form of a crown), could contribute a more constant characteristic in 

 the group of species in which this type of insertion is common. Well! In this regard I 

 found all the imaginable transitions. I determined that neighboring species frequently have 

 staminal positions that are very different. 



The Cereus grandifloris has a staminal crown that is very distinct and separated 

 from the stamen by 3 cms. Whereas two neighboring species, living very closely in all 

 regards, the Cereus rostratus and the Cereus Macdonaldiae Hook, whose enormous 

 flowers have the greatest analogy with the Cereus grandifloris, have there stamen inserted 

 gradually in such a way that the upper ones are not separated from the lower ones. 



In the Phillocactus we again find the same differences. Lastly I analyzed the 

 flowers of the Phyllocactus phylantoides (Cactus alatus), 40 to 50 years old, and the 

 Phyllocactus Hookeri and I was very astonished to ascertain that in those two species all 

 the stamen are inserted in the highest part of the tubule that is to say in the neck. 

 Consequently there is no Separation between the superior and inferior stamen: stamina 

 omnia seen in the Phyllocactus grandis Lern (Phyllocactus guyanensis Brongn). This I 

 found in Orizaba and it is my opinion that it is synonymous to the Cereus oxypetalus 

 D.C On the other hand we found a distinct Separation between the staminal crown united 

 with the inferior staminal fascicles at the place where it begins to widen. The two groups 

 are separated by a free space measuring 5 cms. 



Among the Echinopsis with large flowers that I had the opportunity to examine, I 

 always found a staminal crown very distinctive from the Echinopsis of short tubules. I 

 examined a cinnabarina and numerous varieties of Phyllocactus. These had clearly 

 separated staminal crowns. The Phyllocactus have many varieties, most a very distinctive 

 staminal crown, but the variety cultivated under the name Maximiiiana have their stamen 

 inserted in a way that there is no interval between the superior and the inferior row. 



A species that has a marked exterior resemblance with the Pyllocactus is cultivated 

 under the name Echinocactus cumingii. Its flowers are entirely lateral and it has aureoles 

 that are a few years old. This species seems to be part of the group Pyllocactus with small 

 orange flowers on short tubules with stamen inserted stepwise, exactly the way it is seen in 

 the Echinocereus. (There is an interesting group in regards the insertion of the stamen; 

 Lemaire called it Cleistocactus). Under this name he described more due to appearance 



