What conditions are needed for a particular cactus, you can find out only knowing its name. Some cacti are very similar, yet the conditions are different.
Cacti are not the most common indoor plants, and until recently it was very difficult to find reliable information regarding their species. Meanwhile, if you find out the generic name of a cactus even before purchasing, you can immediately understand whether it is suitable for growing. There are more than 3 tons of species in the cactus family, and taxonomists divide them into 3 subfamilies, which differ in their structure.
Pereskievye
This family is distinguished by round stems and flat leaves, in the axils of the leaves there are many thorns, hard and straight. Flowers are solitary, on pedicels, sometimes inflorescences. Many pereskivs have edible fruits, and the seeds are most often black, with a thin and fragile shell. This subfamily consists of 3 genera, 30 species, 20 of which have normally developed leaves.
The genus Pereskia has 8 species and 4 varieties, and all of them are shrub cacti. Most often in greenhouses you can find peresky prickly and its varieties, in which the undersides of the leaves are red or purple.
The genus Rhodocactus is widespread in Mexico, 13 of its species are known, which also grow in South America and India. Most of its varieties develop poorly in indoor culture and most often do not bloom, for this reason rhodocactus are used to graft zygocactus and other abundant flowering on them.
Opuntia
Most of the opuntia leaves are small, juicy and quickly falling. In addition to thorns, the areoles of prickly pears contain bundles of small serrated bristles, glochidia, which are modified prickly pear leaves. Other subfamilies do not have such a detail. Stems of prickly pears are juicy and segmented, and in different species the segments are different in shape: like cakes, cylindrical, potato-shaped, thickened. The flowers are single, large, regular in shape and of the most varied colors, but yellow ones prevail. Most prickly pears also have edible fruits, and the seeds have a very hard shell and a light prickly seed. Opuntia includes 16 genera and more than 500 species.
Cereus
This is the largest subfamily of cactaceae, in which plants are without leaves and glochidia. There are various cacti, giant and dwarf ones. The shape of the stem and its structure can also be varied, there are serpentine, cylindrical, spherical, supiform, tuberous or papillary cereus. Most species have spines, some fruits are edible. The seeds have a fragile shell and seedlings.
Most Cereus are desert cacti and grow in arid regions, but some are found in rainforests and are epiphytic plants that love very humid and warm climates. These are Selenicereus and Chilocereus.
