7 Prince Salm Sept. 28, 1848 



These "Limits are very difficult to draw, and so insignif icant f 

 sometimes a couple of spines more or less becone so important < in 

 other cases« . All these species seen to be Mexican« -Hr. Gultor, who 

 lived in Mexico sent them ( or at least some of them) first toc 

 Mr. Decandolle; other travellers, the Vandernallen of Brüssel, 

 and the botanical gar den of Berlin-, vi sited only a few areas ^sen- 

 ding ( specimens,E.D# ) to America, while the northern ones were 

 hardly known yet; they musjj therefor be native more soutberly 

 (as also the Pectinati) . Most of them may have come to England 

 through Hr. Potts, Prom all this Your Wellborn will see, that T 

 an, not quite satified with the above division,, 



What further concerns several of your new species, I can say 

 hardly anythlng about Mara. h.emisphaerica_ ( which is still too sraall)!,, 

 M, nigrocalcarata, papyracantha j macr omeri s , conpacta , gumnif era , , 

 and sabatifera (whlch I have never seen); other than, that the 

 first and the last seem to me to belong to M , scolynoidesj speci- 

 ally the latter ( solentlf era) ». 



Your native Oprmtiae interest me ardently. 1 have a very com- 

 plete collection- of this genus and would like to complete it für - 

 ther. Already Op.nacrorhiza and intermedia p:row quite well with 

 me, and I have still another from Mr. Potts, which will be placed? 

 next to Missourlensis, and which I will name 0». Pottsii . He and Hr. 

 Scheer wanted to name it tuber osa^ t Not only does a tuberosa exist 

 already, but the gentleraerr raistook the lowest member, which swells 

 tuberculif orraiter, as the root, The last seeds, for which I am most 

 grateful, looked so good , that I expect germination with confi - 

 dence; nevertheless, plants or even new plantlets would advance 

 me several years.- Yoizr 0p. frutscens, f which I received through Ber- 

 lin,,! conslder as our* vlrgata», and judging from the dead piece of 



