Aloe sabaea
Aloe sabaea
Overview
Aloe sabaea is a solitary, tree-forming aloe with a relatively slender simple trunk and an apical rosette of long, narrow leaves. It is one of the most distinctive Arabian aloes and is notable for a clear exudate with a strong rat-urine-like odour. [1] [2]
Key characteristics
Growth form
Solitary and arborescent, with a simple erect trunk; recent dry leaves persist on the trunk. [1] [2]
Leaves
Leaves form an apical rosette and are narrowly lanceolate-attenuate; young leaves spread, then become recurved and often slightly falcate. [1] [2]
Leaf margin
The pale cartilaginous margin bears weak teeth; near the apex the teeth may be crowded along only one edge. [1] [2]
Inflorescence
The erect inflorescence is a branched panicle. Racemes are erect and cylindrical-acuminate, while open flowers become nodding. [1] [2]
Flowers
The perianth is cylindrical-trigonous and red-toned, rarely orange, with a yellow mouth; the outer tepals are free to the base. [1] [2]
Fruit and seed
The fruit is a capsule. The seeds are black and three-angled, with a grey surrounding wing. [1]
Exudate
Fresh exudate is clear and has a strong rat-urine-like odour; it dries clear. [1]
Distribution
Saudi Arabia; Yemen [3]
Habitat
It is reported mainly from dry, open rocky hillsides, also occurring on cliffs and occasionally talus slopes, and it is not restricted to a single geological substrate. [1]
Ecology and conservation
Pollination
Shining Sunbirds and several bee species are described as the main pollinators, attracted by the copious nectar. [1]
Population and conservation
The 2019 account describes most populations as stable but notes decline or eradication at some sites, including impacts from human encroachment and habitat alteration in Saudi Arabia. [1]
Toxicity and constituents
McCoy (2019) reports toxic compounds in the exudate based on Blitzke et al. (2000) and describes A. sabaea as the only Arabian aloe known to be poisonous. [1]
Diagnostic features
McCoy (2019) considers Aloe ballyi and A. elata close relatives and places the three species in a small species complex based on shared arborescent form, leaf shape, floral/fruit structure and the characteristic exudate odour. [1]
Classification and nomenclature
- Accepted name
- Aloe sabaea Schweinf. [3]
- Synonym
- Aloidendron sabaeum (Schweinf.) Boatwr. & J.C.Manning [3]
- Publication
- Bull. Herb. Boissier 2(2): 74 (1894) [3]
- Compared taxon
- Aloe ballyi
- Compared taxon
- Aloe elata
Etymology
The epithet is associated with Saba/Sheba. McCoy (2019) refers to the Sabaean Kingdom, while The Aloe Names Book says it probably commemorates the state of Saba (Sheba). [1] [4]
References
- McCoy, T. (2019). The Aloes of Arabia. McCoy Publishing, Temecula, California.
- Carter, S., Lavranos, J.J., Newton, L.E. & Walker, C.C. (2011). Aloes: The Definitive Guide. Royal Botanic Gardens, Kew. p. 662.
- World Checklist of Vascular Plants (WCVP).
- Grace, O.M., Klopper, R.R., Figueiredo, E. & Smith, G.F. (2011). The Aloe Names Book. Strelitzia 28. South African National Biodiversity Institute, Pretoria.