Cacti from around the world.
Did you know there are over 2,500 species of cacti?
Most of these succulents thrive in desert conditions.
Here a few pictures of my favorite.
cactus, (family Cactaceae), plural cacti or cactuses, flowering plant family (order Caryophyllales) with nearly 2,000 species and 139 genera. Cacti are native through most of the length of North and South America, from British Columbia and Alberta southward; the southernmost limit of their range extends far into Chile and Argentina. Mexico has the greatest number and variety of species. The only cacti possibly native to the Old World are members of the genus Rhipsalis, occurring in East Africa, Madagascar, and Sri Lanka. Although a few cactus species inhabit tropical or subtropical areas, most live in and are well adapted to dry regions. See also list of plants in the family Cactaceae.
Cacti are succulent perennial plants. Cacti generally have thick herbaceous or woody chlorophyll-containing stems. Cacti can be distinguished from other succulent plants by the presence of areoles, small cushionlike structures with trichomes (plant hairs) and, in almost all species, spines or barbed bristles (glochids). Areoles are modified branches, from which flowers, more branches, and leaves (when present) may grow.
In most species, leaves are absent, greatly reduced, or modified as spines, minimizing the amount of surface area from which water can be lost, and the stem has taken over the photosynthetic functions of the plant. Only the tropical genera Pereskia and Pereskopsis, both vines, have conventional-looking functional leaves, while the leaves of the Andean Maihuenia are rounded, not flattened. The root systems are generally thin, fibrous, and shallow, ranging widely to absorb superficial moisture.
peyote
peyote
Dutchman’s pipe cactus
Dutchman’s pipe cactus
Santa Fe Island
Santa Fe Island
desert ecosystem
desert ecosystem
Cacti vary greatly in size and general appearance, from buttonlike peyote (Lophophora) and low clumps of prickly pear (Opuntia) and hedgehog cactus (Echinocereus) to the upright columns of barrel cacti (Ferocactus and Echinocactus) and the imposing saguaro (Carnegiea gigantea). Most cacti grow in the ground, but several tropical species—including leaf cactus (Epiphyllum), Rhipsalis, and Schlumbergera—are epiphytes, growing on other plants; others live on hard substrates such as rocks, while yet others climb far up trees. Epiphytic species tend to have thin, almost leaflike flattened stems. The appearance of the plant varies also according to whether the stem surface is smooth or ornamented with protruding tubercles, ridges, or grooves.