Aloe arborescens

Aloe arborescens
A. arborescens growing in Kirstenbosch National Botanical Garden, Cape Town, South Africa
Scientific classification
Kingdom:	Plantae
clade:	Angiosperms
clade:	Monocots
Order:	Asparagales
Family:	Xanthorrhoeaceae
Subfamily:	Asphodeloideae
Genus:	Aloe
Species:	A. arborescens
Binomial name
Aloe arborescens Mill.

Aloe arborescens, commonly known as the Krantz Aloe, belongs to the Aloe genus, which it shares with the well known and studied Aloe vera plant. This species is also relatively popular among gardeners and has recently been studied for possible medical uses. It is the only other member of the Aloe family that is claimed to be as effective as Aloe vera for medical uses.

Description

The Aloe arborescens is a large treelike multi-headed shrub and bears its name due to its stem forming habit.^[1] Typical height for this species 2–3 metres (6.6–9.8 ft) high. Its leaves are succulent and are green with a slight blue tint. Its leaves are armed with small spikes along its edges and are arranged in rosettes situated at the end of branches.^[2] Flowers are arranged in a type of inflorescence called a raceme. The racemes are not branched but two to several can sprout from each rosette. Flowers are cylindrical in shape and are a vibrant red/orange color.^[1]

Distribution

Aloe arborescens is mostly native to the south eastern coast of the African continent. Specifically, this range includes the countries of South Africa, Malawi, Mozambique and Zimbabwe.^[2] It has the third largest distribution amongst the aloe genus.^[1] Although Aloe arborescens has adapted to many different habitats, its natural habitat usually consists of mountainous areas including rocky outcrops and exposed ridges. Its common name Krantz Aloe refers to the Afrikaans word "krantz", which means a rocky cliff. Its habitat can vary and is one of only a few species of aloe that is found growing from sea level up to the tops of mountains.^[1]

Distribution of Aloe arborescens

Uses

Medicinal uses

Aloe arborescens shares similar medicinal properties with the well known Aloe vera and is commonly used to treat burn wounds. In a scientific study conducted by Jia et al., wounds were induced in rat and rabbit test subjects and pulp from Aloe arborescens was applied to the wounds.^[3] Results showed that healing rates were improved in wounds addressed with Aloe arborescens. According to the study, applications of the Aloe arborescens extract “tended to significantly reduce the wound severity with respect to that with saline treatment”. In addition to increased healing properties, the study found that Aloe arborescens can be used to reduce microbial growth. The study found that the application had “effectively inhibited the bacterial growth for four bacteria during the observation period of time”.^[3]

Preliminary results show that A. arborescens may be useful in the treatment of cancer as it contains compounds that inhibit cell proliferation.^[4] Recent research in cancer treatment with A. arborescens in a clinical trial involving 240 patients led to the conclusion that aloe may enhance the effects of chemotherapy by increasing its efficacy in terms of both tumor regression rate and survival time.^[5]

Gardening

The Aloe arborescens is a popular plant among gardeners because of its beauty. These plants are known for their succulent green leaves and large vibrantly colored flowers. Its flowers bloom during the winter and is chosen among gardeners to add color to their gardens during the winter season when few other flowers bloom. In addition to their beauty, this species also produces a sweet nectar that attracts birds, butterflies and bees.

In Southern Africa, Aloe arborescens is traditionally planted around kraals (domestic stock enclosures) as a living fence or security hedge. It often happens that the position of old kraals can still be seen many years after they have been abandoned, because the aloes persist.

This aloe is easily propagated by cuttings. ^[1]

References

1. ^ ^{a b c d e} Hankey, Andrew, and Alice Notten. "Aloe Arborescens." PlantZAfrica. Web. 29 Apr. 2010. <http://www.plantzafrica.com/plantab/aloearbor.htm>.
2. ^ ^{a b} "Aloe Arborescens." Aloes of the Huntington Gardens. Web. 29 Apr. 2010. <http://www.calflora.net/aloesofthehuntingtongardens/aloe_arborescens.html>.
3. ^ ^{a b} Jia, Y.; Zhao, G.; Jia, J. (2008). "Preliminary evaluation: The effects of Aloe ferox Miller and Aloe arborescens Miller on wound healing". Journal of Ethnopharmacology 120 (2): 181–189. doi:10.1016/j.jep.2008.08.008. PMID 18773950.  edit
4. ^ Bedini, C.; Caccia, R.; Triggiani, D.; Mazzucato, A.; Soressi, G. P.; Tiezzi, A. (2009). "Micropropagation of Aloe arborescens Mill: A step towards efficient production of its valuable leaf extracts showing antiproliferative activity on murine myeloma cells". Plant Biosystems - an International Journal Dealing with all Aspects of Plant Biology 143 (2): 233. doi:10.1080/11263500902722402.  edit
5. ^ Lissoni P, Rovelli F, Brivio F, Zago R, Colciago M, Messina G, Mora A, Porro G. (2009). "A randomized study of chemotherapy versus biochemotherapy with chemotherapy plus Aloe arborescens in patients with metastatic cancer". In Vivo 23 (1): 171–175. http://www.ncbi.nlm.nih.gov/pubmed/19368145.