155 is. 
. | St. Lovis, February 13, 1848.” 
_ My Dear Sim: Your letter, together with the package containing 
‘the drawings of a number of most interesting cactacee, arrived 
. BO) oe 2 ae ae 
On the occasion of my report on the botany of Dr. Wislizenus’s 
yoyage, I have made a careful investigation of the cactacee, of 
oo 
+s 
to its flower, and a much smaller proportion! in i eee 
--. Tam now able to distinguish all the different genera of cactacee 
by their seed, and sometimes even the different sections of one 
enus. ; 
. The small black shining seed sent me, belongs to a true Cereus, 
probably the plant which you 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- 
| dracea. : 
_ Thave ventured to describe some of your species from the draw- 
‘ing; my description, however, and the names.given by me, must 
remain doubtful till we are ableto-obtain some more data to charac- 
__terize the species. I have written it more for your information than 
' ofc r publication, but if you choose to append it to your published re- 
= ave no objection to it, but must request you to make suc 
i: 
lr 
? 
| 
Cif pet dnt Ped op 8 ae 
___Proliferous in the highes! “c6i™ forming hemispherical mame s 
often of a diameter 34. feet; which are compose of 100— 
ish. PF" eas er ae 
‘his species appears to be allied to. M. vivipara, but is distin- 
uish Po are oe, Ss he hei while 
- flat and spreading masses. ay ee = 
It may be an undescribed species, in which case t 
a - ia m 
‘¢ om we 
Echinocereus, but bunches, re 
ve 
-aggregata appears to be most appropriate. 
2. Mammilaria, October 26, 1846. Rare. Ved: i 
Apparently a mammilaria, though the habit of ai is 
