Cephalocereus Cacti and Succulents
From the Greek kephale, a head, and Cereus, another genus in which these plants were once placed (Cactaceae). These plants grow very tall in their natural state and sometimes branch when old. Most are ribbed with hair or wool at the areole and at the point whereare produced. This develops a cephalium, a thick bunch of wool, which protects the flower bud from the sun. The flowers are mostly small and narrow, almost tube-shaped. There are about 50 species and several are favourite plants with collectors as their white spines and hairs make them particularly attractive.
C. aurisetus, thick stems up to 4 feet high, branching from base, with golden-yellow bristle-like spines, cephalium on one side of stem where flowers are produced, flowers bell-shaped, yellow to white, Brazil. C. chrysacanthus, columnar stem up to 15 feet, glossy-green with golden yellow hairs and spines, some spines brownish. flowers open at night, deep pink, Mexico. C. palmeri, tall, branched bluish-green stems, very woolly areoles, thick cephalium, spines yellow when young, turning to black with age, flowers nocturnal, reddish-green with pink inside, eastern Mexico. C. senilis, the well known old man cactus, a great favourite with cactus collectors, grows tall with dense white hairs and spines, can reach 35-40 feet, in its native habitat, flowers are nocturnal and about 5 inches long, Mexico.
The should be a good porous compost but plants are not particular provided the is good. Repot every three years or as often as they out-grow their pot. Pots must have a large enough base to support the tall plants. Water well during hot weather as often as the soil dries out; give no water in winter.
Temperature 65-70 °F (18-24°C) in summer, 40°F (4°C) in winter.
Many species are easy to raise from seed but take years to reach flowering size. Sow seeds in the early part of the year in reliable seed compost, covering them very lightly. Keep the pots or pans moist warm and shaded, and prick out the seedlings when the cotyledon has become absorbed. Some species make branches which can be detached, the cut ends allowed to dry and then rooted on sharp sand. Tall plants can be beheaded. The base will sprout fresh shoots and the top can be dried and used as a cutting.