ECHINOCACTUS (fig. 3) is the genus bearing the popular name of hedgehog cactus. It comprises nine species, native of the south western United States and Mex ico. They have the fleshy stems characteristic of the family, these being either globose, oblong or cylindrical, and ribbed as in Melocactus, and armed with stiff sharp spines, set in little woolly cushions occupying the place of the buds. The flowers, produced near the top of the plant, are large and showy, yellow and rose being the prevailing colours.
They are succeeded by succulent fruits, which are exserted, and scaly, in which respects this genus differs from Melocactus which has the fruits partly im mersed and smooth. One of the most interesting species is E.
ingens., in which there are 4o to so ridges, on which the buds and clusters of spines are sunk at in tervals, the aggregate number of the spines having been in some cases computed at So,000 on one plant. There are 27 related genera.