General information about cacti
Habitats of cacti
The original main habitat of cacti is on the American continent. On other continents, they have been spread by humans and are there run wild. In Australia for example they developed to a plague until they where reduced through natural parasites that humans used against them.
The main habitat is located between the northern and southern tropic in the arid regions. Which the most occurrences are in Mexico with 64 genera e.g. Ariocarpus, Astrophytum, Echinocereus, Echinofossulocactus, Ferocactus, Mammillaria, Turbinicarpus, Peru with 36 genera e.g. Cleistocactus, Espostoa, Lobivia, Melocactus, Oreocereus, Bolivia with 34 genera e.g. Aylostera, Echinopsis, Gymnocalycium, Mediolobivia, Sulcorebutia, and Argentina with 33 genera e.g. Acanthocalycium, Parodia, Rebutia, Trichocereus.
The most widely occurring species in the north are Opuntia polyacantha and Escobaria vivipara, in the Canadian province of Saskatchewan.
The range of distribution begins around in California and ends in southern Chile. There are individual species and varities which only exist in small areas these are called endemic. Other species grow in several areas which locations are some very well known. For example Carnegiea gigantea in the Saguaro National Park or Stenocereus thurberi in the Organ Pipe Cactus National Monument in Arizona. Typical for these areas is the low spreading of plants. This is due to the rarity occurring rain falls in those areas. It may sometimes happen that there is no rain for several years.
In addition there are high temperatures of about 40°C (104°F) in summer and extreme temperature fluctuations that may drop down over the night sometimes below 0°C (32°F) in winter.
Some species also grow in tropical rain and monsoon forests, such as Epiphyllum and Rhipsalis.
These differ significantly in appearance, as well as in requirements of heat and humidity requirements compared to the genera of the first-mentioned areas.