Cacti are not generally considered good to eat. It's a common misconception that cacti have water in them, but you'll find it's more of a slimey liquid that'll probly make you feel ill.
Some cacti, such as Peyote and San Pedro are also psychedelic, as they contain Mescaline. Although not poisonus per se, it would not be advisable to ingest them as food as the experience can last up to 12 hours, which can be terrible under the wrong conditions.
Other than that, there is no danger so long as you don't eat them and stay clear of the spines :)
Most plants categorized as cacti are not poisonous, but it is an enormous category and some cacti can be very dangerous. Some Euphorbias (technically succulents) have toxic sap, while other actual cacti have irritating barbed thorns that could cause severe reactions in sensitive persons. Some cactus varieties, such as certain prickly Pears and the fruit of some cereus are widely used as food, but as when gathering any plants, you need to know what you are doing before taking the risk of eating any plant part.
Yes sometimes they could be
yes it will kill you
One common way is by poisonous chemicals that the plant contains. For example, the tobacco plant contains nicotine, which is extremely poisonous to many predators. Another way is by thorns and/or spines that make the plant difficult to eat. For example, cacti.
Yes: Prickly Pears, Barrel cacti, Saguaro cacti, Aztekium cacti, and Echinopsis cacti a.k.a the hedgehog cactus
cactus for a single plant cacti for plural
All cacti are succulents, but not all succulents are cacti.
No, mealworms do not eat cacti and cacti do not occur naturally in the Sahara. Cacti are natives to American deserts.
There tons of genera of cacti.
Yes, cacti are dicots.
Many cacti are recognized as having hallucinogenic or narcotic properties and therefore can also be regarded as being poisonous. Cactus fruits are generally regarded as safe, however.
Yes, cacti are freaking awesome
No, cacti do not grow in the Arctic.
Yes they do have cacti. Epiphyllum, Rhipsalis, and Schlumbergera are a few genera of cacti that grow in the rainforest.
No cacti grow naturally in the Sahara. Cacti are natives of the Americas, not Africa.