These are very popular plants in collections and very suitable for cultivation on window-sills. They are endemic to the southern half of S. America, to the east of the Andes, which they have apparently not been able to cross. The plants are short, and cylindrical or globose in shape. The genus includes about 36 species. Although they love plenty of light, they should, during spring and summer, be given a little shade during the brightest hours of the day. They are easily cultivated, requiring a moderately richof 1 part loam, 1 part soil, 1 part sharp sand, and if a little old cow manure can be obtained, a half part can be added to the . Established plants produce off-sets, and often these are already rooted on the plant. They are easily separated and should be potted up and grown on to produce specimen plants.
Echinopsis multiplex. S. Brazil. Globular, with 12 to 15 slightly wavy ribs. Brown spines; radials numbering 8 to 10, and centrals 2 to 5. The are magnificent and fragrant, flesh-coloured, shading to pink at the point. There are many hybrids of this species.
Echinopsis eyriesii. Brazil, Uruguay and Argentina. Frequently found in collections. The stems are globular, and produce a host of young plants along the ribs. The spines of this species are very short, and number about 14. Theare borne on the sides of the plant, and are similar to E. multiplex, but are white.
Echinopsis rhodotricha. NE. Argentina and Paraguay. A very free-flowering species with dark green oval or cylindrical stems, sprouting at the base, and having 8 to 13 ribs. Radial spines number 4 to 7, with 1 central spine, but this is, however, often absent. The spines are yellow and somewhat curved. The plant bears slender white flowers, at the base of which are scales with red woolly hairs.
Echinopsis turbinata. S. Brazil and Argentina. Theis dark green, globular or conical, and sprouting at the base, and has 13 or 14 ribs. Radial spines number 10 to 12, and are at first yellowish-brown, changing to horny brown; there are 6 central spines, very short and stiff, black or dark brown. The flower is funnel-shaped, with a green tube, the outer petals being dark green, the inner petals white with a greenish mid-rib.
Echinopsis decaisneana. Has large and beautiful red flowers. Easy to grow fromand a desirable plant.
Echinopsis tubiflora. S. Brazil and Argentina. Stems globular, with age cylindrical, dark green; ribs II to 12, notched with acute furrows between them; radial spines numerous, yellowish and brown at tips; central spines 3 or 4 and stronger; outer petals of flower green, tipped brown, inner petals white with a green mid-rib on the dorsal side. Three varieties are in cultivation: var. nigrispina, var. Paraguay ensis, and var. Graessneriana. These are all popular beginner s plants. The distinguishing feature is the long tube of the flower. They do well in a living-room and will flower when about 3 inches in diameter.