How to identify and how it grows
The Traveler’s Compass has a peculiarity which helps to identify it, usually leaning toward the southwest, and this gives it the common name. The plants grow as solitary stems to the height of about five feet and the diameter of a foot and a half. The plants are globose when young, gradually becoming cylindrical and having as many as thirty ribs, two inches high and three inches apart. The rib crests are obtuse and are constricted between the areolas. There are from six to eight radial spines, an inch or two long, which are stout and straight with cross ridges, and spreading. They are gray, or dull red and pink, with the tips a translucent yellow. The central spines are much stronger than the radials, as long as three inches, extending outward and not hooked; but the tips are curved. The flowers, which are bell-shaped, are about three inches long and have forty petals and twenty sepals. The petals have acute tips and are oblanceolate. The colors vary from yellow to crimson and red shadings with the margins of a lighter red. The fruit is elliptical, about two inches long and a dull yellow.
How to grow
Transplant in sandy gravelly or rocky soil at any season, with enough water to keep the soil moist during the growing season. Plants grow easily from seed in flats in sandy loam with part shade, watered occasionally to keep the soil slightly moist. The plants grow inside and outdoors and are not injured by temperatures twenty-five degrees below freezing; in colder weather they should be protected.
Turk’s Head (Echinocactus horizonthalonius)
(The specific name horizonthalonius is of unknown origin but no doubt refers to the position of the spines)
How to identify and how it grows
The Turk’s Head has as many as eight radial spines, three to five of which grow directly upward and two to four extend laterally. Many of them grow to one and one-half inches long. The central spines are much stouter and longer, extending outward, also, and downward, about two inches in length. All the thorns are quite stout, are strongly cross-ridged and curved, and in many instances are twisted. Near the lower ends they are grayish and tone off to a dull brown at the tips. This plant is of the solitary-stem variety and grows to about one foot high and six inches or less in diameter. It is cylindrical and usually is found with eight spiral ridges less than an inch high and two inches apart, which are rounded and light gray or light blue-green. The areolas are rather well crowded together. The flowers are about two inches long and have a delicate deep pink to rose-pink coloring, opening only in the bright sunshine and for just one day. The flower is composed of thirty-eight spatulate petals and fourteen sepals. The style is a bright pink. The fruit is oblong and has a dense woolly growth of long cream-white hairs; when ripe it is red. These plants grow well in the arid rocky or stony soils of the open desert and foothills, never in great abundance.
How to grow
Set plants in the spring in gravelly or stony soil in sunny locations with good drainage, and give enough irrigation to retain the moisture in the soil during the growing season. Plants grow readily from seed in pots or flats in sandy loam, in part shade, with enough water to keep the soil lightly moist. The plants grow outside and inside and are not injured by a temperature of twenty-five degrees below freezing.