The spines in M. macromeris are straight, and measure 2 in. in length; in M. multiceps they are in two series, the one fine, white, and short, the other yellow and stout.  The most marked section of this genus, however, is that represented by M. fissurata (Fig. 61), in which the tubercles are large, spreading horizontally, and angular, resembling most closely the foliage and habit of some of the Haworthias.  No one who had not read up the botany of Mamillarias would suspect that this plant belonged to them, or even to the Cactus order at all.  There is a good specimen of it in the Kew collection.  When in flower the family resemblance is easily seen; but as this species does not flower freely, it will be known by its remarkable foliage-like tubercles, rather than as a flowering Cactus.  And the same remark applies to many of the Mamillarias; their stems thickly beset with tubercles and spines, always regular in arrangement, and neat and attractive in appearance.

The following remarks made by Dr. Lindley when describing M. tenuis, give a good idea of the singular, yet pretty, 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 conceive the curious beauty of this little herb—­a plant so unlike all others that we would 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.”  It is quite true that in the cultivated Mamillarias there is nothing unsightly, or rough, or unfinished.  Without foliage, their stems globose, or short cylinders, or arranged in little cushion-like tufts, and enveloped in silky spines, like tiny red stars, always looking the same, except when in flower, and never looking in the least like ordinary plants.  Characters such as these ought to find many admirers.  In the Succulent House at Kew, there is a long shelf upon which a great many plants of this genus may be seen.  But the flowers in some of the species of Mamillaria are quite as attractive as the stems.  Those of M. macromeris are 3 in. long and wide, their colour a deep rose; M. Scheerii has equally large flowers, and coloured bright yellow, as also are the flowers of M. pectinata.  This last is remarkable on account of the clock-like regularity with which its flowers expand.  While fresh, they open every day between eleven and twelve o’clock, and close again about one, however strong the sunlight shining upon them may be.  Some of the kinds (more especially the small-flowered ones) are often prettily studded over with bright red, coral-like berries, which are the little fruits, and contain, as a rule, matured seeds capable of reproducing the parent plant.