Chapter XII. 

 MAMILLARIA. 



Over 300 Mamillarias are known. They are characterised by short, 

 symmetrically- formed stems, sometimes aggregated together 

 and forming a dense tuft, or with only a single stem. The closely- 

 set, spirally- arranged tubercles or mamillre, vary considerably in 

 the different kinds. Some have stems only 1 inch high by f inch 

 in diameter, with tubercles hidden by the star-shaped cushions 

 of reddish or white spines. In others, the spines are erect and hair- 

 like, giving the plant the appearance of tiny sea-urchins ; another 

 group has the principal spines hooked at the tip, and as sharp as 

 fish-hooks. The purpose of these hooked spines seems doubtful ; 

 certainly, they cannot be of use as a protection, as they are so 

 strong that the plant would be torn up by the roots before the hooks 

 gave way. 



Some of the species, such as M. angularis, form large cushion- 

 like masses not unlike those formed by the sheep plant (Ravulia) 

 of New Zealand. M. clava is described as forming clumps com- 

 posed of about fifty plants 2 feet high, each plant bearing about 

 a dozen large ye'low flowers open at one time, and making a 

 most gorgeous display on the plains of Mexico. The spines in 

 M. macromeris are straight, and measure 2 inches in length ; in 

 M. multiceps they are in two series, the one fine, white, and short, 

 the other yellow and stout. 



The following description of M. tennis, by Dr. Lindley, gives a 

 good idea of the stems of some of these plants : " Gentle reader, 

 hast thou never seen in a display of fireworks a crowd of wheels 

 all in motion at once, crossing and intersecting each other in every 

 direction ; and canst thou fancy those wheels arrested in their 

 motion by some magic power their rays retained, but their fires 

 extinguished and their brightness gone ? Then mayst thou con- 

 ceive the curious beauty of this little herb a plant so unlike all 

 others that we should fain believe it the reanimated spirit of a 

 race that flourished in former ages, with those hideous monsters 

 whose bones alone remain to tell the history of their existence." 

 f Without foliage, their stems globose or cylindrical, or packed close 

 together in little cushion-like tufts, enveloped in silky spines, 

 like tiny red stars, they are very different from ordinary plants. 

 The flowers of many of the species are quite attractive. Those of 

 Jf. macromeris are 3 inches long and wide, their colour a deep rose ; 



