512 Cultivatio7i of the Cacti. 



flower plentifully, and produce an abundance of fruit ; and they are 

 not infested by insects, which is unavoidably the case in hothouses. 



These are the advantages which are obtained from a success- 

 ful treatment of this favourite genus of plants. Many gardens 

 now possess a very perfect collection by following this plan. 



The Melocacti, on the contrary, require a higher degree of 

 temperature, and therefore ought to be in the hothouse. Most 

 of them come from the West Indies, Cura9oa, St. Thomas's, 

 &c. There are sevei'al varieties in this group, which approach, 

 more or less, to the Melocactus communis. Whether they are 

 all to be considered as varieties must be, from careful considera- 

 tion, afterwards determined. Most of the original plants evince 

 by their roots that they grow in a red loamy and stony soil ; and 

 these, in my opinion, should also be cultivated as I have mentioned. 



The Echinocacti require somewhat more heat than the mam- 

 millarias, yet they may be cultivated in beds in the open air in 

 summer. In winter they should be kept in a temperature of 8° 

 or 10° of Reaumur (50° to 54*5° Fahr.), and ought to have but 

 very little water ; and if they have taken firm root in summer, 

 they may be kept quite dry, and will not be in any danger. 

 From this necessary state of rest, a profusion of flowers will be 

 produced on the plants. 



Many doubts still exist as to the species of Cereus, as they 

 vary so much both in their habit, and spine and angular forma- 

 tion ; and the situations in which they are found do not seem to 

 make any exception in this respect. A recent traveller and 

 collector informed me that he found from four to six difl^erent 

 forms on the same stem, so different that even the greatest con- 

 noisseur would have supposed each separate branch to have been 

 another species; and his specimens confirmed the assertion. 



The genus Cereus, with the exception of some species, flowers 

 more sparingly than those of Mammillaria and Echinocactus ; 

 but, from an improved method of cultivation in modern times, 

 many species have been brought into flower that were formerly 

 not expected. Most of the species may be cultivated in the 

 open air, in a protected sunny situation, in summer ; and it is 

 better if they can be on beds that have a little bottom heat at 

 first ; and this can easily be effected in gardens where there is 

 plenty of leaves and manure, as pits can be dug, and these 

 materials put in, and then covered with earth, and the plants 

 sunk into it. They grow extremely well in this manner, are 

 much stronger, and look a great deal better, than when they are 

 continually standing in a hothouse. Several species of Mexican 

 Cereus can be kept through the winter in a moderately heated 

 greenhouse. Those alluded to are such as C. chilensis, cine- 

 rascens, pentalophus, ovatus, articulatus, Marti«;»^s, flagriformis, 

 Mallison/, SmithzV, Schrank//, coccineus, Ackermann/, &c., with 

 all the varieties of C. speciosissimus, &c. 



