If you were to close your eyes and picture a cowboy in the American Southwest, chances are good that there's a cactus in that picture, pardner. In fact, Mexico and the southwestern US are hot spots for cactus biodiversity.
Cactuses typically grow in deserts and semi-desert regions, and many can go months without rain. Some cactuses, though, are rainforest varieties. These cactuses are mostly epiphytes (plants that grow on other plants). The Cactus Family is endemic to North, Central, and South America—with one genus that's an exception: Rhipsalis can be found high in the trees in rainforests of Africa, Madagascar, Sri Lanka, and the Mascarene and Seychelle Islands.
A cactus' sharp spines protect the plant from most herbivores, although rodents, woodpeckers, and collared peccaries may snack on cactus stems. Spines may also help to shade the stem, collect moisture from dew or fog, and break up evaporative winds. Continue reading from San Diego Zoo Wildlife Alliance
Plants are a kingdom of life forms that includes familiar organisms such as trees, herbs, bushes, grasses, vines, ferns and mosses. Through photosynthesis, they convert water and carbon dioxide into the oxygen we breathe and the sugars that provide the primary fuel for life. Through nitrogen fixation, plants generate proteins that are basic building blocks of life. Early fossil records of photosynthesizing organisms date from about 3 billion years ago. Continue reading from The Center for Biological Diversity
