Aloe is a genus of flowering succulent plants.
The genus is native to tropical and southern Africa, Madagascar, Jordan, the Arabian Peninsula, and various islands in the Indian Ocean.
Today, it is widely grown in warmer climates globally, and indoors.
There are about 500 species of Aloe.
The most widely known species is Aloe vera, or “true aloe”, so called because it is cultivated as the standard source of so-called “aloe vera” for assorted pharmaceutical purposes.
Most Aloe species have a rosette of large, thick, fleshy leaves.
Many species of Aloe appear to be stemless, with the rosette growing directly at ground level; other varieties may have a branched or unbranched stem from which the fleshy leaves spring.
They vary in color from grey to bright-green and are sometimes striped or mottled. Some aloes native to South Africa are tree-like (arborescent).
Aloe flowers are tubular, frequently yellow, orange, pink, or red, and are borne, densely clustered and pendant, at the apex of simple or branched, leafless stems.
Aloe are much cultivated as ornamental plants, especially in public buildings and gardens, for their stiff, rugged habit.
Aloe has been marketed as a remedy for coughs, wounds, ulcers, gastritis, diabetes, cancer, headaches, arthritis, immune-system deficiencies, and many other conditions when taken internally. However, the juice of the leaves of certain species, such as Aloe venenosa, is poisonous.
Some Aloe species are used in treating skin conditions, alternative medicines, and in home first aid. Both the translucent inner pulp as well as the resinous yellow exudate from wounding the Aloe plant is used externally to relieve skin discomforts.
Many well-known patent medicines consist essentially of Aloe.
Aloe has been used medicinally for more than 3500 years.
Egyptian texts, dating to about 1500 BC, describe its healing properties.
Alexander the Great used it to treat wounds.
A beautiful violet dye is produced from Aloe plants (A. perryi) native to the island of Socotra in the Indian Ocean. A desire for the plant is said to have motivated Alexander the Great to conquer the island in the 4th century BC. 1400 years later, Muslim traders reported the island was still the only source of the herb, although it is now grown in Africa, China, India, and Central America.
Aloe perryi, A. barbadensis, A. ferox, and hybrids of this species with A. africana and A. spicata are listed as natural flavoring substances in the US government Electronic Code of Federal Regulations. Aloe socotrina is said to be used in yellow Chartreuse.
Note that the plant sometimes called “American aloe” (Agave americana) belongs to Agavaceae, a different family. Some consider the Aloe and agaves justifiably to be placed in the same family.