The term “Aloe Vera” commonly refers to just one specific species, but Aloe is a vast genus of flowering succulent plants belonging to the Asphodelaceae family. This genus is incredibly diverse, encompassing over 600 recognized species native primarily to Africa, Madagascar, and the Arabian Peninsula. While the many species share the characteristic of fleshy, water-storing leaves, only a handful possess the widely recognized medicinal properties.
The Medicinal Standard: Aloe barbadensis miller
The plant universally known and commercially dominant as “Aloe Vera” is scientifically named Aloe barbadensis miller. This species is the gold standard for both topical and internal health products due to its unique chemical makeup. The leaf of A. barbadensis miller is composed of three distinct layers.
The clear, mucilaginous inner leaf fillet, or gel, is the most prized component, making up roughly 99% water. The solid material contains beneficial compounds, including polysaccharides like acemannan, vitamins (A, C, E, and B complex), minerals, and amino acids. This gel is widely used for its soothing, hydrating, and anti-inflammatory properties, making it popular for treating minor burns, dry skin, and digestive issues.
Positioned just beneath the leaf rind is the bitter yellow fluid known as aloe latex. This latex contains high concentrations of anthraquinones, notably aloin, a powerful compound with strong laxative effects. Because of aloin’s intensity and safety concerns, commercially prepared aloe products often undergo a process to remove or significantly reduce the latex content. Products intended for internal consumption should only contain the purified inner gel, not the whole leaf extract or the latex.
Diversity Beyond the Standard
The vast majority of Aloe species exist entirely outside the medicinal spotlight. Many species are cultivated primarily for their striking ornamental value, showcasing a wide range of unique forms and colors. These non-medicinal types illustrate the incredible morphological diversity within the genus, ranging from small, clumping rosettes to towering tree-like structures.
An example of a distinct species is Aloe ferox, often called Cape Aloe or Bitter Aloe. This large, tree-like aloe is sometimes harvested for its leaf pulp, which reportedly contains nearly double the amino acids of A. barbadensis miller. However, it is most recognized for its extremely high concentration of aloin in the latex, making it a stronger source for laxative supplements.
Other species are celebrated purely for their aesthetic qualities.
Ornamental Varieties
The Spiral Aloe (A. polyphylla) is highly valued for its leaves that grow in a perfectly organized, mesmerizing spiral pattern. Aloe arborescens, the Candelabra Aloe, is a shrub-like variety that can grow several feet tall with multiple branches, producing showy, bright red flower stalks. The Lace Aloe (A. aristata) is a compact species covered in small white bumps that give it a distinctive texture, making it a popular houseplant.
Identifying Key Species
The true medicinal plant (A. barbadensis miller) typically grows as a stemless or short-stemmed rosette with thick, fleshy, lance-shaped leaves. The leaves are a gray-green color and have small, serrated teeth along the margins.
A key identifying feature relates to the white spots that often appear on the leaves. On A. barbadensis miller, these spots are prominent only when the plant is young or juvenile. As the plant reaches maturity and the leaves thicken, these spots typically fade, leaving the mature leaves a solid, uniform gray-green.
In contrast, common look-alikes, such as Aloe chinensis or various spotted ornamental hybrids, often retain their white spots even on mature leaves. The leaves of A. chinensis are also thinner and narrower than the fleshy leaves of the true medicinal type. Accurate identification ensures the plant harvested contains the beneficial gel compounds.