24 



ECHINOCACTUS Sc8pa. 

 The Broom Cactus. 



ICOSANDRIA POLYGYRIA. 



Nat. ord. Cactace^!. 



ECHINOCACTUS. DeCand. Prodr. 3. 461. Revue des Cactees, 

 p. 35. 



E. Scopa ; caule oblongo multicostato, fasclculis spinarum approximatis basi lana- 

 tis, subulis extimis 30 40-debilibus albis centralibus 3-4 purpurascentibus 

 rigidis, petalis biseriatis luteis apice serratis. 



Cactus Scopa. Link enum. plant, hort. beroL ii. 21. 



Cereus Scopa. Princeps Salm-Dyck in DeCand. prodr. iii. 464. 



Echinocactus Scopa. Hort. Berol.Jide Pfeiffer Cact. p. 66. 



A native of Brazil, whence it was many years since sent 

 to Prussia, and thence distributed through other parts of 

 Europe. It derives its name of the Broom Cactus from 

 having the hairs of its stem so long and stiff as to resemble 

 that instrument. Dr. Pfeiffer mentions two varieties, one 

 with all the hairs white, the other with the central ones 

 purple, as in the accompanying figure. 



The latter was taken from a specimen which flowered in 

 the valuable collection of Thomas Harris, Esq. of Kingsbury. 



Some explanation of my having placed this plant and the 

 two species formerly represented in this work, in the same 

 genus, seems to be required. After eliminating the Melo- 

 cacti because of their producing their flowers in the woolly 

 receptacle peculiar to those plants, the Mammillarias on 

 account of their tubercles not being confluent into ridges, 

 and the Opuntias because of their rotate flowers and leafy 

 spiny sepals, there remains a considerable number of species 

 formerly included under the old genus Cactus, whicli modern 

 writers have divided between the two genera Cereus and 

 Echinocactus. Now this partition may be effected in two 



May, 1839. k 



