ON CACTI AND OTHER SUCCULENTS. 



797 



fall away from the base and leave scales. The flower is bright 

 yellow, and appears near the centre. 



Mammillaria.— Many species of this genus are very beautiful. 

 They are all dwarf, and the tubercules are surmounted by 

 rosettes of stiff hairs or spines, from the midst of which the 

 flowers come. The blossoms are of various colours — yellow, rose, 

 or white. Many also bear berry-like fruits resembling coral. 

 Sorts : M. angularis branches freely, and is bright green with rose- 

 coloured flowers, which, however, are rarely seen under cultivation. 



Fig. 532. — Epiphyllum Russellianum. 



M. bicolor is very common and also distinct, on account of the 

 hair-like white spines borne in clusters on the ends of the 

 tubercles ; it is cylindrical and often branches, presenting a curious 

 appearance ; the flowers are deep purple. M. cirrhifera is very 

 neat in form ; it has angular tubercles and yellow, twisted spines ; 

 the flowers are rose - coloured and small. M. dolichocentra 

 (Fig. 533) is rather variable; it is about Sin. in height, with small, 

 cone-shaped, smooth mammae ; the flowers are small, but very 

 numerous, and of a pale purple colour ; the bright rose-coloured 

 fruits are also pretty. M. elephantidens (Fig. 534) is one of the 



