Written by Sandra Lennox and Catherine Clulow
With water restrictions underway in South Africa, there is a far stronger need to encourage water-wise gardening and promote indigenous plants. Today we are talking about the rich variety of different Aloe species found in Limpopo Province. These unique and beautiful plants are hardy, drought tolerant and water-wise.
1. Aloe lettyae
This is a grass aloe, easily recognised by spots visible on both the upper and lower leaf surfaces. Plant population dynamics and conservation of this species are currently being studied thanks to funding from the Botanical Education Trust.
This rare summer-flowering Aloe grows amongst the spring flowers of the Woodbush Granite Grassland and may be seen while on one of the hour long wild-flower walks during the annual mid-September Spring Festival, led by the Friends of Haenertsburg Grasslands (FRoHG). The rare Aloe plants were photographed one cloudy and cool day, while accompanied by eco-enthusiasts from nearby towns as well as the dog Pluto, who watched closely.
The land had been burnt and several plants were in flower, belying the fact that there had been little rain. This shows that underground storage organs such as bulbs and tubers are an important part of the survival of these grassland species, hence clearing land for example for firebreaks irreparably destroys the integrity of the flora. The grasslands have established over a long period of time.
Coincidentally meanwhile the CITES convention had started in Gauteng, to discuss the preservation of endangered species such as elephant, pangolin and rhino. While scientists and policy makers talked, there are those who walked, appreciating the priceless value of the grassland wildflowers. Rare and endangered plants with medicinal value have been listed for the Woodbush Granite Grasslands (Dzerefos et al. 2016).
2. Aloe greatheadii var. greatheadii
This is the spotted aloe with spots on the upper leaf surfaces. This species is relatively commonly and is an important plant for bees as the pollen has a high protein and lipid nutritional content.
The spotted aloe, or kgopane (Setswana) produces its spectacular flowers in the winter months (June-July). The plants are stemless, occurring singularly or in groups of up to 15 plants, up to 1.7 m high. The dark, shiny green leaves present with spotted, elongated markings arranged in bands on the upper (adaxial) surface, while the leaves are light green and not spotted underneath (abaxial surface). The one to three inflorescences are branched. Each raceme presents 30-40 pale pink to bright red flowers. Aloe greatheadii var. greatheadii is pollinated by bees and birds. Wind distributes the seeds.
This species occurs in the Grassland and Bushveld Biomes, in open woodland and in overgrazed areas, at altitude from 1,000 to 1,660 m. It is distributed throughout the Free State and northern KwaZulu-Natal. Aloe greatheadii is named after Dr. J.B. Greathead who collected the type specimen with Dr S. Schönland. The bitter sap is medicinal and is used as a treatment for burns, sores and wounds. The young leaves are chopped and boiled for use as an antiseptic.
In the garden, seeds of this species can be germinated in a mix of sand, compost and river sand. Cover with pebbles. Keep in a dry and warm environment. Avoid drying out the growth mixture. Plants are frost and fire tolerant and are used as soil binders on mine dumps.
3. Aloe marlothii
This is a very large, single stemmed Aloe often seen in large stands along the road between Polokwane and Tzaneen, interestingly this is unusual as explained later.
The large, single stemmed Aloe marlothii occurs in bushveld vegetation on rocky ridges from sea level to approximately 1,600 m at warm temperatures with infrequent frost. It is commonly known as the Mountain Aloe, Bergalwyn (Afrikaans), inhlaba or umhlaba (Zulu), Aloe marlothii is distributed from the north-western, northern and north-eastern part of Southern Africa and is rewarding to cultivate.
Aloe (Greek) refers to the product of dried juice from the leaves, Alloeh (Sanskrit) and Allal (Hebrew). The species epithet refers to the botanist H.W. Rudolf Marloth. These Aloes are associated with the African iron age archaeological sites on the Polokwane (formerly Pietersberg) plateau where the distribution is an anomaly in terms of climate and ecology. The dense stands consist of 80 to 100 year old plants.
It is thought that plants were introduced as seeds near the Ndebele villages as the spiny leaves were used to prepare hides for dresses, dried leaf ash may be added to snuff, the flower nectar is edible and leaf decoctions may be used as a vermifuge. The succulent Aloe marlothii plants are suited to drought conditions, as water is stored in stems and leaves, though kudu browse the leaves during dry conditions, thorns protect the rough leaf edges from browsing, dried leaf bases defend the stems and the plant height enables escape from browsers while surviving drought.
4. Aloe arborescens
This is the most commonly cultivated of the Southern African Aloes. The Aloe leaf gel can be used to heal sunburn.
This species is commonly known as the Kranzaloe (Engl.), Kranzalwyn (Afr.), ikalene (Xhosa), inhabane or umlabana (Zulu). It occurs on cliffs in mountainous regions, rocky ranges and outcrops and in dense bush. It occurs in summer rainfall regions and has the widest distribution of the Southern African Aloes, from the Cape to the eastern coast, KZN and northern South Africa, from sea level to higher altitudes.
The cliff dwelling form was formerly known as Aloe mirabilis. Aloe arborescens tolerates drought and it is moderately frost resistant. This is one of the most widely cultivated Aloes in the world. It is one of the first Aloes collected for cultivation from South Africa. The inflorescences are unbranched and flowers emerge during winter (May to July). These are commonly orange, rarely pure yellow or a combination of orange and yellow. The nectar is edible to birds such as sunbirds as well as bees.
Aloe arborescens is recommended as a key component of herb gardens. A leaf decoction may be used as an antiseptic and for indigestion and it has also been used in stock and poultry farming. The leaf powder is considered to have protective properties against storms. Aloe arborescens are useful barrier plants and as a hedge. In rural areas, remnants indicate fenced enclosures or cattle kraals.
Aloe lettyae highlights the conservation value of the grasslands. Aloe greatheadii is present as a spotted, grass aloe. Aloe marlothii has been introduced for its economic value. Aloe arborescens is widely cultivated and an early subject for gardens having been collected from the wild. All Aloes are water-wise their flowers bring colour to the garden.
This article was written with assistance from the Friends of Haenertsburg Grasslands, FRoHG and the Tzaneen Eco-club with inspiration from Gariep nursery, Pretoria which specializes in the cultivation of Aloe. The photos were taken by Pat Lennox.
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