Aloe barberae is a striking sculptural tree aloe bearing
a rounded, neat crown. It forms an excellent focal point in the
garden. It is easily distinguished by its grey, smooth bark, green
recurved leaves and pink flowers during winter. It thrives in cultivation
and is easily propagated. Due to its massive stem base, it should
preferably not be planted close to any buildings.
Description
Aloe barberae is Africa's largest aloe reaching up to
15 m in height and 0.9 m in stem diameter. The branching is forked
or dichotomous and eventually forms a spreading, rounded crown.
It leaves are arranged in a dense rosette, they are long, narrow,
deeply channelled and curved. The leaf surface is dark green with
a toothed margin. The inflorescence is simple or divided into three
side branches. The racemes are cylindrical and its tubular flowers
rose pink (green-tipped) and appear during June and July.
Distribution
Its habitat is subtropical coastal forests, kloofs and dry valleys
in the summer rainfall eastern regions of southern Africa. Aloe
barberae is widely distributed from near East London in Eastern
Cape through the former Transkei area, KwaZulu-Natal, Swaziland
and Mpumalanga and northwards to Mozambique and East Africa.
Derivation of name and historical aspects
This plant was first discovered by Mary Elizabeth Barber, who
was a plant collector in the former Transkei. She sent specimens
of the plant and its flowers to the Royal Botanic Gardens at Kew,
where it was named by Dyer (1874) in her honour. Subsequently it
was also found in the Tugela River Valley (KwaZulu-Natal) by the
well known traveller, explorer and painter Mr. Thomas Baines in
1873. He sent a specimen to Joseph Hooker at Kew, where it was named
in his honour. Although known for many years as Aloe bainesii,
Aloe barberae was the name first given to this plant, and takes
precedence according to the International Code of Botanical Nomenclature.
The genus name Aloe is derived from a Greek word and refers
to the dried juice from the leaves. There are about 350 species
of Aloe which are widespread in Africa and the surrounding
islands, as well as the Arabian Peninsula.
Ecology
This tree grows in warm, well-drained river valleys and coastal
forest where the climate is mild and rainfall is at least 1 016-1
524 mm per annum and with little or no frost. The seeds often germinate
in the shade of other plants and eventually outgrow their companion
plants. The soil is usually a loam and humus rich. In habitat the
plants are pollinated by sunbirds. The capsules ripen during late
spring and release their seed which is wind dispersed.
Growing
Aloe barberae
Aloe barberae is easily cultivated from truncheons as well
as seed and smaller stem cuttings. It is fairly fast growing, but
should be well watered and enough compost provided for optimal growth.
It is sensitive to frost and in a frost-prone area should be protected
in the first few years of its life. Always provide a well-drained
site, on a slope is best. Enough space should be provided for its
eventual size. The leaves may be attacked by aphids and scale insects,
which are controlled with an oil-based spray.
References
- Coates Palgrave, M. 2002. Trees of Southern Africa.
Struik Publishers, Cape Town
- Leistner, O.A. 2000. Seed Plants of Southern Africa, Families
And Genera, Strelitzia 10. NBI, Pretoria
- Smith,G.F. et al. 1994. Aloe barberae to replace A.bainesii.
Bothalia 24(1)34-35.
- Nichols,G. 2001. A great sculptural species. Farmers Weekly
29June:p.87
- Ernst Van Jaarsveld, Personal communication
Giles Mbambezeli
Kirstenbosch National Botanical Garden
June 2003
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