132 ECHINOCACTUS POLYCEPHALUS. HEDGEHOG CACTUS. 



occupy the place of the upper radial ones. The central spines 

 are always very stout, but very different in size. In some speci- 

 mens we find them one and a quarter to one and three quarters 

 inches, while in others they are two to three and a half inches 

 long. They are nearly straight, or very much curved. The 

 upper one is often one and a half to two lines wide, the lower 

 one the longest. The yellow flowers seem to make their 

 appearance in February, as the fruit ripens in March. The 

 ovary and the fruit are enveloped in dense, pure white, cottony 

 wool, which originates from the axis of the lower sepals, and 

 through which only the dark, reddish-brown spinulose points of 

 the sepals are visible." 



All the species of the genus to which our plant belongs were 

 formerly classed as Cactus; but as they became better known, 

 it was found necessary to separate them, and set them up in a 

 family by themselves. The new genus was called Echino- 

 cactus, from echinus, a hedgehog, because many of the species 

 are round and spiny like the animal named. There are Echino- 

 cactuscs, however, which, from their general appearance, might 

 be supposed to belong to other genera, while there are also 

 species in other genera which at first sight might be taken for 

 " Hedgehog Cactuses." The objection might, therefore, be 

 raised that the name is not quite appropriate, did we not know 

 that a name can never fully express character ; and the specific 

 appellation, /^/)/^^///^/^^^ or "many-headed," is open to the same 

 objection. The reason for this name is apparent enough from 

 the description quoted ; but there are other species, even among 

 the genus to which our plant belongs, which might claim the 

 title with equal justice. 



The E . polycephalus is now under cultivation at the Bussey 

 Institute, where it was received from Lower California. 



Explanation of the Plate.— i. Complete single head of a flowering plant. — 2. Longi- 

 tudinal section of a flower. — 3. Sketch, on a reduced scale, showing the niany-hcaded 

 character of the species. 



