Agapanthus africanus subsp. africanus
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Agapanthus africanus subsp. walshii
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Agapanthus are one of South Africa's best known garden
plants and are grown in most countries in the world. Their strap-like
leaves and striking blue or white flowers make them favourites in
plant borders as well as in containers. They are all easy to grow
except for A. africanus and A. walshii which a recent
publication (Zonneveld & Duncan 2003) has proposed is a subspecies
of A. africanus.
Agapanthus africanus was the first Agapanthus
species collected in South Africa and was described in 1679 by the
name Hyacinthus Africanus tuberosus, flore caeruleo umbellato. Plants
were grown in containers in conservatories and flowered in Europe
in the late seventeenth century. Sometimes Agapanthus africanus
is still referred to as Agapanthus umbellatus and many laypersons
as well as nurserymen confuse Agapanthus africanus with Agapanthus
praecox, which is a popular, easily grown species. Any Agapanthus
referred to as 'africanus' in the nursery trade is almost certainly
Agapanthus praecox.
Agapanthus africanus subsp. africanus
Distribution
Agapanthus africanus subsp. africanus is found only
in the Western Cape Province, which is a winter rainfall area. The
plants grow from the Cape Peninsula to Swellendam, from sea level
up to 1000 metres, mainly in mountainous terrain in acidic sandy
soil. They often grow between rocks and even in depressions on sheets
of sandstone rock. The plants will not tolerate freezing weather
for any length of time.

Description
The perianth segments of A. africanus subsp. africanus
are thick in texture and the flowers are open faced and range in
colour from light to mainly deep blue. Rare sightings of white flowered
plants have been recorded. Fires stimulate profuse flowering. After
a recent fire in the Silver Mine Nature Reserve on the Cape Peninsula
a single white flowered plant was noted amongst thousands of blue
flowered ones. The plants flower mainly from December to February.
The leaves are evergreen and strap like, about 15 mm wide with an
average length of 350 mm. The flower stalk is usually under 700
mm tall. This subspecies is quite common and because of the fairly
inaccessible terrain its survival is assured.
Agapanthus africanus subsp. walshii
(Leighton) Zonn and Duncan comb.nov.
In a recent publication, Agapanthus walshii has been renamed
as a subspecies of Agapanthus africanus. The authors, using
nuclear DNA content (2C) and pollen vitality and colour are proposing
that the ten species recognised by F.M. Leighton in her 1965 Agapanthus
revision be reduced to six species and the name change Agapanthus
africanus subsp. walshii has been published. This reclassification
needs further study into the morphological characteristics of the
plants to be fully supported.

Distribution.
This
Agapanthus grows only in the Steenbras area of the Western
Cape Province in a fairly restricted area. Although it was originally
thought to be rare, it is fairly plentiful within its distribution
area most of which falls within a conservation area and its future
seems secure. Unfortunately an informal housing settlement has arisen
in an unrestricted area where most of a colony of plants has been
destroyed or is in danger of disappearing due to human activity.
Agapanthus africanus subsp. walshii is found only
at an altitude above 600 m and grows in very rocky areas in sandy
acid soil.
Description
The flowers are pendulous, often light blue, seldom dark blue and
rarely white. The leaves are evergreen, mainly erect and on average
10 mm broad and 200 mm long. The flower stalk is 600 mm tall. It
also flowers best after a fire.
Ecology of A.africanus
Pollination is by wind, bees and sunbirds. Baboons and buck sometimes
eat the flower heads just as the first flowers begin to open. The
seed which is often parasitized is dispersed by the wind. These
plants are adapted to survive fire in the fynbos. They resprout
from thick, fleshy roots.
Growing Agapanthus africanus
Both subspecies of Agapanthus africanus are
difficult to grow. A africanus subspecies africanus
is not suitable as a garden plant except in rockeries. They are
best grown in containers in a well drained, slightly acid sandy
mix and appear happiest if pot bound. They seem to grow best in
shallow containers and will flower regularly if fed with a slow
release fertiliser.
A. africanus subsp. walshii is by far
the most difficult agapanthus to grow. The best medium appears to
be a very well-drained, sandy, acid mix with minimal watering in
summer. It can only be grown as a container plant and will not survive
if planted out. It is unfortunate that it is so hard to grow because
it is most attractive when in flower and would make an excellent
pot plant.
Both subspecies can be propagated by fresh seed. The seed germinates
best if sown in a well-drained seed mix and lightly covered. The
seed trays should be placed on heated beds under a mistspray set
for about five minutes twice a day. Germination takes place in 4
to 6 weeks and the trays should then be removed to a lightly shaded
area. Good results will also be obtained when the trays are placed
indoors or outdoors in light shade and watered twice a day, provided
the day time temperature is higher than 18° Celsius.
References
- Leighton, Frances M. 1965. The Genus Agapanthus L'Heritier.
Journal of South African Botany, Supplementary Volume No.
IV
- Duncan, G. 2002. Grow Agapanthus. Kirstenbosch Gardening
Series, National Botanical Institute, Cape Town.
- Zonneveld, B.J.M. and Duncan, G.D. 2003. Taxonomic implications
of genome size and pollen colour and vitality for species of Agapanthus
L'Heritier (Agapanthaceae). Plant Syst. Evol. 241: 115-123
(2003).
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Richard Jamieson
Centre for Home Gardening, Kirstenbosch
May 2004
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