2 



as possible according to your instructions. This herbarium will be of great use in 

 comparing the flowers among themselves, I have as yet not had the opportunity to prepare 

 in this way flowers of the Pilocereus. I am sending you enclosed 2 plants I want to call 

 your attention to and seek your advice. The first is the Echinocactus horripilus Lemaire. 

 In regards this unusual species, that has already been planted in France for about 30 years 

 and that I found in Mexico close to Saltillo. We encounter the same question that you have 

 had in regards the Mammillaria micromeris. This Echinocactus horripilus which until 

 recently has been included in the group of the Thelocactus. It has flowers on top of the 

 mammilary tubercles just as seen on the Echinocactus. The flower comes out of the areola 

 immediately below the spines. The areola is grooved as in the Echinocereus Scheerin, 

 uncinatus and many others. The ovary of the flower is entirely bare . Even though I 

 examined the flower most carefiilly I did not find it to be squamous but very similar to the 

 one of the Mammillaria conoidea, as you will see. 



Now if we admit that the essential characteristic that differentiates the Mammilaria from 

 the Echinocactus, lies in the bare ovary then this plant should be ranked under the 

 subgender Epithelantha next to the Mammillaria micromeris even though its exterior 

 appearance distinguishes it from the Mammillaria. If on the other hand we say that this 

 plant should be called Echinocactus, each time the flower comes out of the areola ( as you 

 have demonstrated in your Echinocactus papyracanthus in addition to the Cactus flora 

 pg. 198), then we must admit that the Echinocactus with bare ovaries should not be the 

 same as the Mammillaria micromeris but an Echinocactus and consequently a sub-gender 

 Epilantha ( Ovarium nudicum; flowers in the apex, tuberculorum nascertina; areola 

 ßurigerae oculigeris arete junctae). 



Therefore the question is to know if this group has to be classified with the Mammillaria 

 or rather with the Echinocactus. 



The Echinocactus Williamsii is similar to a group ofAnhalorium. One could include them 

 in our group by eliminating from the Classification the word oculcigeris. I believe however 

 that the Echinocactus Williamsii has more affinities with the Anhalorium. Does your 

 Echinocactus papyracanthus have a bare ovary? Then it should be part of our group. I 

 greatly regret not recognizing the fruits of the seed of the Echinocactus horripilus', the 

 plant greatly resembles in its exterior appearance and the interior of the flower, the 

 Mammillaria conoidea ( where they differ only in the grooves of the mamillae). I suspect 

 they form only wood and the seeds must be similar. In the Mammillaria conoidea the 

 wood is green, turning almost white when it matures. It is spherical like the seeds of a 

 white raisin; the seeds are black as in the Anhalorium. In Mexico where I saw the 



