Karura Forest #34: Aloe Aloe!?
The cache, a small black-taped/marked screw-capped plastic pot, is hidden under a small rock and leaf litter at the foot of a small tree just off the south side of the Tara Path in the northern part of the forest. The cache location is close to an open rocky area which is well populated by aloes (species?) and cacti - including a fine large specimen of the latter a few metres south of the cache.
To reach the cache location, after parking at KFEET head north via Junctions 12, 11, 27, 26, 30 and 37 to access the Tara Path which crosses the Ruaka River just east of Huruma Village (see here for map with trail names and Junction numbers). Follow this up and then contour east to the cache location (passing numerous caches along the way!). See GC4PD3V Karura Forest #1 for background information on the forest, including features, access, maps and useful links.
Aloe is a genus containing 500+ species of flowering succulent plants with even more synonyms and unresolved species, subspecies, varieties, and hybrids. The genus is native to tropical and southern Afirca, Madagascar, Jordan, the Arabian Peninsula, and various islands in the Indian Ocean (eg. Mauritius, Reunion, Comoros, Seychelles). A few species have also become naturalized in other regions.
The best known is Aloe vera ('true aloe') which though probably extinct in the wild is cultivated as the standard source of aloe vera for assorted pharmaceutical purposes. Other species, like Aloe ferox, are also cultivated or harvested from the wild for similar uses.
Kenya has over 60 species of aloe, East Africa has at least 90 whilst South Africa has the most of any country with over 170 species.
Uses: Aloes are often cultivated as ornamental plants both in gardens and in pots. Many are highly decorative and are valued by collectors of succulents. Aloe vera is used medicinal both internally and externally although documentation of clinical effectiveness is relatively limited. They can also be made into types of special soaps.
Historically only a few species have been used as herbal medicines with aloe vera being the most common with others including 
A. perryi and A. ferox. The Ancient Greeks and Romans used it to treat wounds and in the Middle Ages, aloin, the yellowish liquid found inside the leaves was used as a pugative.
Unprocessed aloe containing aloin is a stimulant-laxative treating constipation by inducing bowel movements, whereas the processed aloe juice does not usually contain significant aloin. However In May 2002, the US Food & Drugs Administration (FDA) ruled that aloe laxatives are no longer generally recognised as safe and effective, and they are no longer available there over-the-counter (OTC) as they may be carcinogenic.
Some species, particularly Aloe vera, are used in alternative medicine and first aid. Both the translucent inner pulp and the resinous yellow aloin from wounding the aloe plant are used externally to relieve skin discomforts. As a herbal medicine, Aloe vera juice is commonly used internally to relieve digestive discomfort. Other possible benefits for treating cancer and diabetes have not been clinically confirmed in humans.
The juice of aloes has been used medicinally for many centuries and the three most effective have been A. vera, A. ferox (from South Africa) and A. secundiflora (from Kenya and Tanzania). In addition to the medicinal uses there is a growing interest in recent years for aloe gel to be used in the production of soft drinks, soaps, hair shampoos, skin moisturising and tanning lotions and wound healing preparations.
The additional demand for aloe gel has lead to serious destruction of aloe species in the wild, especially in Kenya, due to the misconception that all wild species are A. vera, which has resulted in conservation measures becoming necessary to prevent them from becoming extinct in their natural habitat. Unfortunately the conservation measures are not rigorously enforced so that the species in the wild are being seriously depleted. Aloe farming is however becoming commercially viable and in Kenya many acres of A. secundiflora are being propagated and planted. One word of warning is that there are at least two species indigenous in Kenya which are poisonous so do not treat yourself in the wild unless you are sure you know the species.
See here for a detailed paper on Sustainable Use of East African Aloes: The Case Of Commercial Aloes In Kenya and here for an illustrated presentation on Experience and Outlook for Kenyan Aloes.