Download S/Reed and Ginger - Botanical Society of South Africa

Weeds in our Area (Part One Hundred and Thirty Nine)
By Bob and Ena McIntyre – Garden Route Region.
UPDATED LIST: Callistemon viminalis (Weeping bottlebrush)
and C.citrinus (Lemon bottlebrush) - FAMILY: Myrtaceae
(BOTTLEBRUSHES)
Coming across these as new entries to the list was a given. Certainly an old
friend from the past, Callistemon species have populated gardens for many,
many years. Loved by landscapers and garden enthusiasts for its
undemanding growth habits, predictable growth patterns and attractive
colourful “bottlebrushes”, the hardy Callistemon species have had ample
time to become fully adapted throughout our country where it also has no
natural enemies. Becoming invasive was a matter of time only. In Australia its
country of origin, Callistemon species are
sometimes used as food plants by the larvae of
a moth of the genus Aenetus. The larvae burrow horizontally and
then vertically down into the trunk. The plants have been grown in
Europe since a specimen of Callistemon citrinus was introduced to
Kew Gardens in London by Joseph Banks in 1789. In South Africa
named cultivars were introduced to the local trade during the
1980’s. These cultivars were superior to the originals because the propagation technique of using
cuttings rather than seed ensured that the plants grew true to form. Growing from seed often
resulted in poor flower colour. It is worthwhile to note that Callistemon was recently placed into
the genus Melaleuca.
Description: Callistemon are bushy evergreen shrubs or medium-sized
trees. Generally dark grey-green in colour, the narrow lanceolate leaves
are sharply pointed and have a firm, hard texture. The branches are stiffly
woody. In our area the plants thrive in the mild climate growing rapidly
into very substantial specimens that need regular hard pruning to keep
them in check. C.viminalis bears its bright red flowerheads at the ends of
the arched drooping branches - hence the very descriptive Afrikaans
common name that translates directly into “weeping horse-tail”. The
flower petals are tiny and inconspicuous while the very showy filaments
are in fact the stamens with the pollen at their tips. Although the flowers
are generally shades of pink and deep red there are yellow, orange, white and green versions.
Numerous specimens abound throughout our region and can be seen along streets, in sports
grounds and the centre island of the N2.
Invasive status: Every flower-head produces a profusion of triple-celled seed capsules around a
stem (see picture) which interestingly in some species remain on
the plant with seeds enclosed until stimulated to open when the
plant dies or fire causes the release of the seeds. In the new list
C.citrinus is classified as Category 3 (Invasive species regulated by
activity) while C.viminalis is classified as Category 1b (Controlled as
part of a control programme) in KZN, Mpumalanga, Limpopo and
Eastern Cape and Category 3 in the rest of the country. Examples of
their invasive tendencies can be found in the forest area around the Garden Route dam where
they had spread from an original grouping at the picnic area.
Substitutes: Rhus lancea (Karee), Olea europaea subsp. Africana (Wild Olive), Freylinia lanceolata
(Honeybells), Buddleja salviifolia (Sagewood) .
References: www.wikipedia.org. A-Z of Gardening in SA: W G Sheat, Ornamental Shrubs and
Trees: Una vd Spuy.