''Echinocereus'' is a genus of ribbed, usually small to medium-sized,

cylindrical A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infini ...

shaped

cacti A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Greek ...

, comprising about 70 species native to the southern United States and Mexico in very sunny, rocky places. Usually the flowers are large and the fruit edible. The name comes from the Ancient Greek ἐχῖνος (''echinos''), meaning "hedgehog", and the Latin ''cereus'' meaning "candle". They are sometimes known as hedgehog cacti, a term also used for the '' Pediocactus'' and '' Echinopsis''.

Description

The species of the genus Echinocereus grow solitary or branching with prostrate to erect shoots that are spherical to cylindrical. The roots are fibrous or bulbous. The plants reach heights of growth between 1 and 60 centimeters. On the tips of the 4 to 26 ribs, which are mostly clear and only rarely resolved into humps, are the areoles, from which differently shaped spines can arise. The small to large, funnel-shaped flowers arise at the top of an areole or break through the epidermis. They are usually brightly colored and open during the day. Their pericarp and floral tube are studded with thorns, bristles, and sometimes wool. The scar is usually green, but sometimes white in color. The spherical to ovoid fruits are green to red and mostly thorny. They are mostly juicy and open along a longitudinal slit. The sometimes fragrant fruits contain broadly oval, black, tuberous seeds 0.8 to 2 millimeters long.

Cultivation

''Echinocereus'' spp. are easier to cultivate than many other cacti. They need light soil, a sunny exposure, and a fresh and dry winter to flower. They grow better in soil slightly richer than other cacti. In the wild, several of the species are cold hardy, tolerating temperatures as low as -23°C, but only in dry conditions.

Species

The following species are recognized in the genus ''Echinocereus'' by

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Formerly placed here

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Echinopsis candicans ''Soehrensia candicans'' is a species of cactus from northern and western Argentina (Monte Desert). It has large fragrant white flowers that open at night., pp. 260–261 Description ''Soehrensia candicans'' has a shrubby growth habit, with indi ...

'' (Gillies ex Salm-Dyck) F.A.C.Weber ex D.R.Hunt (as ''E. candicans'' (Gillies ex Salm-Dyck) Rümpler)

References

External links