(Named from the plant’s habit of growing in clumps) How to identify and how it grows This plant is a fine and showy Pincushion cactus growing from single stems or in clumps, six to fifteen inches in diameter across the top of the clump, the stems globose or cylindrical, two to four inches in diameter. The tubercles are arranged spirally in fifteen to seventeen rows, with twenty to forty radially placed spines in two series like the teeth of a comb. They are less than a half-inch long. There are six central spines in the more mature plants, and all the spines are of a translucent white, toning into the reddish brown tips. The flowers are very showy and are formed around the center of the plant, two or three inches in diameter and bright pink to rose-purple. They remain open all day, and are quite abundant in southeastern Arizona and New Mexico on prairie lands and _bajadas_. How to grow Plants grow outside and are not injured by temperatures as low as zero. They grow easily from seed in sandy or clay loam in flats or pots with some shade; transplant at any season in almost any soil; give enough water to keep the soil moist during dry spells, about five gallons of water at a time. Arizona Pincushion Cactus (_Coryphantha arizonica_) How to identify and how it grows This cactus grows in dense clumps six inches to two feet or more across, with the heads close together. They are shortened, globose or cylindrical, one to two inches in diameter, and as high. The plants are almost hidden by the dense growth of reddish brown or almost black spines. There are from fifteen to thirty radially placed spines and three to seven stouter central thorns, all of which have yellowish bulbous bases, with red-brown or almost black tips. The flowers are about an inch and a half long and as wide. The petals and sepals are narrow and lance-shaped, and from tan-purple to rose or rose-purple. The fruit is oval and light green. This cactus grows in the prairie lands and on foothill slopes, and needs a little modern irrigation. How to grow This Pincushion is not injured by temperatures of twenty to twenty-five degrees below zero and hence is well suited for growing in cactus gardens throughout the country. It thrives also in the warm Southwest. Young plants grow readily from seed in pots or flats, in sandy or loamy soil, with enough irrigation to keep the soil moist; part shade is desirable. Large plants prefer sandy or loamy soil, especially limestone soil with irrigation about once a month, and some shade. California Pincushion (_Mammillaria tetrancistera_) (Named _tetrancistera_ in allusion to the four central spines) How to identify and how it grows