About cactus
A 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 word κάκτος (káktos), a name originally used by Theophrastus for a spiny plant whose identity is now not certain. Cacti occur in a wide range of shapes and sizes. Although some species live in quite humid environments, most cacti live in habitats subject to at least some drought. Many live in extremely dry environments, even being found in the Atacama Desert, one of the driest places on Earth. Because of this, cacti show many adaptations to conserve water. For example, almost all cacti are succulents, meaning they have thickened, fleshy parts adapted to store water. Unlike many other succulents, the stem is the only part of most cacti where this vital process takes place. Most species of cacti have lost true leaves, retaining only spines, which are highly modified leaves. As well as defending against herbivores, spines help prevent water loss by reducing air flow close to the cactus and providing some shade. In the absence of true leaves, cacti's enlarged stems carry out photosynthesis. Cacti are native to the Americas, ranging from Patagonia in the south to parts of western Canada in the north—except for Rhipsalis baccifera, which also grows in Africa and Sri Lanka.

Cactus

green cactus plant
green cactus plant
green cactus plant on white panel
green cactus plant on white panel
cactus plants on field during daytime
cactus plants on field during daytime
brown cactus plant on orange background
brown cactus plant on orange background
green succulent in teal ceramic vase
green succulent in teal ceramic vase
brown and green trees on brown field during daytime
brown and green trees on brown field during daytime
green cactus during daytime
green cactus during daytime
green cactus plant in white background
green cactus plant in white background
green cactus in brown pot
green cactus in brown pot
Cheerful elderly woman on an outdoor hike carrying a backpack and walking stick while resting near a large cactus. A fit old woman on a hike enjoying the freedom of adventure and a healthy vacation
Cheerful elderly woman on an outdoor hike carrying a backpack and walking stick while resting near a large cactus. A fit old woman on a hike enjoying the freedom of adventure and a healthy vacation
green cactus with flowers
green cactus with flowers
green cactus
green cactus
closeup photo of cactus against white background
closeup photo of cactus against white background
shallow focus photography of cactus
shallow focus photography of cactus
green cactus by rocky mountain during daytime
green cactus by rocky mountain during daytime
cactus plants under blue sky during daytime
cactus plants under blue sky during daytime
green plant under blue sky during daytime
green plant under blue sky during daytime
red flower in green plant
red flower in green plant