Aloe

Aloe is a genus of flowering, succulent leaf perennials in the Asphodelaceae family and previously the wider genus of Liliaceae.

The Aloe name is said to be derived from the Arabic word, alloeh and the Hebrew one, allal, both meaning bitter, referring to the bitter juice of many Aloe leaves.

Some Aloe plants have stems, even long ones, others are stemless, rarely even bulbous. The plants form groups and branch or grow solitary and single-stemmed. In size they range from small and low-growing to 20 m tall. The plants may be erect, decumbent or scandent, occasionally pendulous as in hanging from cliffs. The roots are mostly succulent and cylindrical.

The succulent leaves are often arranged in rosettes, sometimes in two opposing ranks (distichous) or only so when young; in number few to numerous. Leaves last for several years in many species, deciduous in some.

The thick, succulent leaves are usually ovate, lanceolate or triangular, tapering to acutely pointed tips. In some species the leaves spread, ascending in others or recurve. Some leaves are spiny on one or both surfaces, with or without toothed margins. Others have fringed margins, rarely entire ones. Leaves may be green, bluish, reddish, or yellowish, some with spots or other leaf markings on one or both blades, or on parts of them.

The inflorescence is a single raceme or multiple ones in a panicle. The racemes are cylindrical, cone-shaped or flat-topped (capitate). They may be positioned erectly, angled or horizontal. Inflorescences range in size from 10 cm to 3 m, their peduncles cylindrical to flattened and softly herbaceous to woody. There are bracts below the pedicels of individual flowers, usually also sterile ones below panicle branches. Many or few flowers may open simultaneously in a band ascending up the raceme.

The flower corollas are tubular perianths, straight or curved, globular, club-shaped or cylindrical to three-angled. The perianths are sometimes constricted above the ovary, sometimes two-lipped as seen at the tips. The six segments are arranged in two whorls of three with free tips that often cohere when withered.

Flower colours range from yellow, orange and red to brown, green or white, sometimes two- or even three-coloured on the perianth and the bud sometimes differently coloured to the open flower.

The six stamens occur in two whorls of three, emerging from below the three-locular, superior ovary. The stamens are exserted or included in the perianth, in accordance with the nature of the species. The free filaments are cylindrical to flattened, often coloured as the perianth. The placentas where the ovules are attached grow on the central axis inside the ovoid ovary. The style is single, the stigma small at its tip.

The fruit is a three-locule capsule, in shape usually ovoid or a short, rounded cylinder. It is erect, drying to a papery or woody texture before opening. The variously brown, angled seeds have some form of wing attachment, which is papery in some species.

The genus possibly comprises over 500 species, although several genera have been split off from it in recent times. Plants now called Aloidendron, Aloiampelos, Gonialoe, Aristaloe and Kumara all still used to be Aloe around the turn of the twenty first century, some only reclassified around 2013 to 2017.

Also the South African count of about 125 species may still have to be adjusted downwards due to these changes. The South African list of aloes was possibly started in 1699 containing only four species. Such a list was reported to some authority in the Netherlands by the early explorer of the Cape, Olof Bergh, via an added letter by Jan Hartogh, chief gardener at the Cape at the time. The four plants mentioned were probably ones drawn or painted by Hendrik Claudius, an artist at the Cape originating from Breslau in Prussia, now Wroclaw in Poland.

Claudius was part of the entourage of both Bergh’s inland journey in 1683 for bartering cattle from the Khoi and Simon van der Stels exploration of Namaqualand in 1685 for investigating the possibilities of copper mining. His brief on these trips was a common sideline on such occasions: to depict animals, birds and plants, whatever may be of interest encountered in a land blessed with fauna and flora hugely surprising and exciting to many early visitors from Europe. Reporting back to interested parties in Europe, as well as exporting samples, descriptions of findings and art works depicting these novelties to the "home" countries were big issues in those days.

The complete South African Aloe species list today contains the largest number of species of any country, while many African and Mediterranean countries have their own aloes, sometimes endemic ones. Several islands near Africa, notably Socotra and Madagascar also boast many of their own Aloe species.

Aloes have been hugely important in medicine and cosmetics since time immemorial. Aloe remedies have appeared in human recordings from before the time of the Greeks. References to historic Aloe usage in ancient Egypt, Sumer (today southern Iraq) and other countries around the Mediterranean are readily available in the literature.

The uses continue in many parts of the world. Aloe vera is the prime species in cosmetic and medicinal applications worldwide. In South Africa it is mainly A. ferox that is strongly established in a multitude of modern products and traditional uses.

The plant in picture is A. striata, one of the few species with no spines or teeth (Leistner, (Ed.), 2000; Van Wyk and Smith, 2003; Reynolds, 1974; Wikipedia).