Questa è una di quelle piante che non possono mancare in una collezione di cactacee, la sua maggiore attrattiva sono le dense spine pettinate di un bellissimo color rosa-viola.
Echinocereus rigidissimus var. rubrispinus (the varietal epithet meaning red-spined)
Synonyms: Echinocereus pectinatus var. rubrispinus
Origin: Mexico (northern Sonora, north-western Chihuahua
Habitat: The reported habitat preference for limestone is erroneous; this species is a calcifuge, preferring soils poor in lime and usually acid.
Common Name: Rainbow cactus, Ruby Rainbow.
NOTE: Echinocereus rigidissimus, lacking central spines, belongs to the E. reichenbachii group, unrelated to the superficially similar E. pectinatus group, which has at least microscopically visible stubs of central spines. It sometimes occurs with E. pseudopectinatus but without evidence of hybridization.
Echinocereus rigidissimus rubrispinus (LAU 088 Sierra Oscura, W. Chihuahua, MX)
Cultivation: E. rigidissimus var. rubrispinus is not the easiest cactus to grow, but when grown well it’s very attractive. Rot easily it is sensitive to overwatering (rot prone), so perfect soil drainage is a must. It prefer a neutral to slightly acidic compost with plenty of extra grit. Best if watered with rain water and given an occasional tonic of sequestrated iron. In the summer they need an airy location in bright sun; well watered when it's hot. To achieve the best spine colours give these plants lots of sun.In the winter light, cool, and absolutely dry conditions. Very cold resistant above approx -12C or less for short periods of time. In mild climate they grow well when planted freely outside in well-drained soil.