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The Hilton daisy is a strikingly beautiful grassland plant that
occurs around Pietermaritzburg in KwaZulu-Natal. The species is
under considerable threat of extinction due to habitat fragmentation
and degradation resulting from agriculture and urban sprawl.
Description
The species is a low-growing herb with thick, thong-like roots,
and rosettes of elliptical, dark green, leathery leaves. The plants
grow vegetatively by underground stems to form clones which can
reach over a metre in diameter and are thought to be hundreds of
years old. Plants typically die back during the dry winter months
and leaves begin to emerge in spring.
As with all daisy family plants, the 'flowers' are not single flowers
but a head made up of many tiny florets massed together. The 'petals'
(ray florets) are usually a striking crimson, but may be orange,
pink or yellow on the upper surface and are coppery below. It is
thought by some that the colour variations might have resulted from
hybridization with a close relative, Gerbera ambigua. The
disc florets in the 'flower' centre appear black or dark purple
when the inflorescence opens, changing to yellow as the pollen is
presented. Flowering takes place in spring, from September to November,
when the daisies form spectacular masses in the grassland.

Orange form
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Pink form
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Distribution
G. aurantiaca is endemic to the mistbelt grassland region
of KwaZulu-Natal and is currently known from approximately 9 scattered
populations from Helahela in the south to Babanango in the north.
This is a summer rainfall area, which experiences very cold winters,
often with snow in some localities.Hilton daisies typically occur
in rocky grassland between 900 and 1 500 m, on warm slopes in well-drained,
shallow soils associated with doleritic formations.Most localities
are burnt annually.

Derivation of name and historical aspects
The genus Gerbera is named after the German naturalist Traugott
Gerber who started the first botanical garden in Moscow in the 1700s.
However, to date no one has been able to find any connection between
Gerber and the genus.
The specific name aurantiaca is, rather suprisingly, from
the Latin aurantiacus or orange-yellow. Perhaps this refers
to the coppery orange undersurface of the petals.
The common name is derived from the village of Hilton near Pietermaritzburg,
where the daisies once grew in profusion.
A close relative of the Hilton daisy is the well-known Barberton
daisy, (Gerbera jamesonii),
which is one of the parents of the popular Gerbera hybrids
used extensively in the cut flower and nursery trade.
The genus Gerbera has approximately 14 southern African species,
some of which are found only in Western Cape.
Ecology
Gerbera aurantiaca has been selected as the flagship species
of the Natal National Botanical Garden's SABONET-funded Threatened
Plants Programme. The programme is combining a study of the population
biology of the Hilton daisy in the wild, together with the establishment
of ex situ populations from the major localities, and the
selection and propagation of some of the most attractive varieties
for horticulture.
The
pollinator of the Hilton daisy is thought to be the brown hairy
monkey beetle which feeds on the pollen, and probably uses the flowers
as rendevous platforms for mating. The large pollen grains get caught
in the hairy body of the insect and are carried to the next flower
that the beetle visits where they may be brushed off and pollinate
receptive florets. A number of insects feed on the developing seedheads
and can severely reduce seed set.
The
seeds with their hairy parachutes which aid in dispersal, are carried
short distances by the wind. However, seedlings are seldom seen
in the wild, although the seed germinates readily.
Uses and cultural aspects
The Hilton daisy does not appear to be used for traditional healing
purposes. However, as it is such an attractive plant, that in the
past, keen gardeners frequently dug plants out of the wild to grow
in their gardens. This was virtually never successful and the plants
are notoriously difficult to grow in cultivation.
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Growing Gerbera aurantiaca
Please note that the collecting of threatened plants such as the
Hilton daisy, or their seed, is prohibited by law. In addition,
as mentioned in the previous section, these plants are reputed to
be extremely difficult to grow.
However, as part of the Threatened Plants Programme at the Natal
National Botanical Gardens, we are studying ways of establishing
populations out of the wild for conservation purposes. This involves
the cultivation of the plants. Seed collected from the wild germinates
well immediately after collection. There is a high mortality in
the first year, possibly due to fungal infection. Once established
the plants do not like to be disturbed.
References
- HILLIARD, O.M. 1977. Compositae in Natal. University
of Natal Press. Pietermaritzburg
- JOHNSON, I.M. 2003. The decline of the daisies. Veld &
Flora 89: 31.
- POOLEY, E. 1998. A field guide to the wild flowers of KwaZulu-Natal
and the eastern region. Natal Flora PublicationsTrust, Durban.
- SCOTT-SHAW, C.R. 1999. Rare and threatened plants of KwaZulu-Natal
and neighbouring regions. KwaZulu-Natal Nature Conservation
Service, Pietermaritzburg.
Isabel Johnson
Natal National Botanical
August 2003
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