r 



Ex. Doc. No. 41. 155 



■ 



has not hitherto obtained a place in bur Flora. We have it from 

 Alabama, Florida, Texas, and various parts of California. 



Lycopodium. A small species allied to L. rupestre, was found 

 in descending the Gila. It differs in its incurved leaves, which are 

 mucronate,but without a bristle at the tip. No frQctification exists 

 in the specimen. 



St. Louis, February 13j 184S. 



My Dear Sir: Your letter^ together with the package containing 

 the drawings of a number of most interesting cactaceee, arrived 

 safely here about two weeks ago. . 



• the occasion of my report on, the botany of Dr. Wislizenus's 

 voyage, I have made a careful investigation of the cactaceiE, of 

 ^hich he brought home with him more than 20 species, and have 

 been enabled to elucidate several points which had been unknown, 

 or obscure before; no doubt because in the hot-houses of European 

 gardens, these curious plants, though they thrive^pretty well, rarely 

 produce flowers and fruit; so that from 800 species of cactacese at 

 present cultivated in Europe, perhaps not one fourth is known as 

 to its flower, and a much smaller proportion in fruit. 



i am^ now able to distinguish all the diff^erent genera of cactacese 



by their seed, and sometimes even the different sections of one 



genus. ' . ■ 



J-he small black shining seed sent me, belongs to a true cereuSj 



probably the plant which ypu mention under the name of pitahaya, 



the larger- opaque .black seed is that of an echinocactus^ and the 



largest white seed is the seed of an opuntia of the section cylin- 

 drace(B, 



1 nave ventured to describe some of your species from the draw- 

 &; iny descriptions, however, and the names given by me, must 



ernain doubtful till we are able to obtain some more data to charac- 



enze the species. I have written it more for your information than 

 for publication,* but if you choose to append it to your published re- 

 port, I have no objection. to it, but must request you to make such 

 corrections or alterations as your notes or your recollection of the 

 plants will enable you to do; for example, as to size, as in some of 

 tne drawings no size is mentioned,* in which case I have assumed 



"^m to represent the natural size, I have, for convenience sake, 

 iiumbered the different figures, and shall now proceed to copy for 



1^ \ descriptions and remarks following my numbers. 

 ^ 1. Mammilaria, October 18, 1846. 



-^^^if^i^ous in the highest degree, forming hemispherical masses 

 Jf ten of a diameter of 3^ feet; which are composed of 100— 200 



Querent heads or stems. Single heads conical, apparently about 

 or 5 inches high, and 2^ — 3 inches in diameter; color, bluish 

 g^eenj spines white or reddish. 



m 



V here the size is not mentioned, the original drawings are the size of pature. W 



