
This is probably the largest family of flowering plants, with more
than 25 000 species world-wide, growing from sea-level to the highest
mountain peaks. It is absent only from Antarctica. In southern Africa
it is also one of the biggest families of flowering plants with
about 246 genera and 2 300 species. Many of the species have economic
value. They show remarkable variation in growth form and general
morphology because they occur in so many different localities and
habitats.
Derivation of name and subdivisions:
The alternative family name Compositae is derived from the Latin
word compositus which means 'made up of parts united in one
common whole'. This refers to the collection of different florets
arranged together in an inflorescence. For family names, the modern
tendency in taxonomy is to use the name of a familiar plant in a
certain family and to add the suffix -aceae to the name. In this
way the family name Asteraceae is made up by using the name Aster
and adding -aceae.
The family is divided into three subfamilies
and a number of tribes. In the National Herbarium, Pretoria,
we accept 18 tribes.
Description
Almost all the features generally occurring in plants, can be found
in this family! There are annual, biennial or perennial herbs, dwarf
shrubs, shrubs, a few trees, some scramblers and aquatics. Some
are succulent, whereas while others are spiny and some have milky
sap. Many perennial species are adapted to survive the cold, dry
winter season of the highveld by underground storage organs and
producing annual stems in spring. The leaves can be arranged alternately,
opposite or whorled along the stem; sometimes they are situated
at the base of the stem (radical and rosulate) or in groups. Some
have a petiole while others are sessile. The leaves can be simple
with smooth margins or the margins can be toothed, lobed or variously
dissected to such an extent that the leaves are actually compound
with numerous leaf segments. Many species in the karroo and fynbos
vegetation have small, needle-like leaves to survive the hot, dry
summer seasons. These leaves look almost like the leaves of the
genus Erica, and are called ericoid.

The 'flowers' are the feature that distinguishes
this family from all other plant families.
Uses and economic value
The economic value of the representatives of this family can be
divided into various categories: food for man and beast, poisonous,
weeds, medicinal, wood, garden plants and cut flowers.
Food for man: The most well known food product of the family
is certainly sunflower oil and kernels. Other well-known foods are
Jerusalem and French artichokes, lettuce, chicory and herbal tea
like camomile.
Food for animals:species of this family grow in so many
habitats and localities, many of them are good grazing for stock
e.g. sandbietou or tickberry (Chrysanthemoides
monilifera subsp. pisifera), blouheuningkaroo (Felicia
muricata), witheuningkaroo (Phymaspermum parvifolium)
and bierbos (Pteronia membranacea).
Poisonous species: There are, however, many species that
are poisonous to stock e.g. vermeerbos (Geigeria species),
kaalsiektebos (Chrysocoma ciliata) and bloubietou (Dimorphotheca
spectabilis).
Weeds: The fruits (cypselas) with their hair or scale-like
pappus are easily distributed by the wind. Therefore many species
have become weeds and some are distributed world-wide. Well-known
weeds are dandelions (Taraxacum species), cosmos (Cosmos
bipinnatus), blackjack (Bidens species) and burweed or
boetebossie (Xanthium spinosum).
Medicinal: Many species have traditionally been used medicinally
as they are so easily obtainable. Many of the medicinal plants belong
to the tribe Anthemideae, whose representatives are often aromatic.
Well-known medicinal plants are wilde-als or African wormwood (Artemisia
afra), kapokbos or wild rosemary (Eriocephalus
africanus) and wild camphor bush (Tarchonanthus
camphoratus).
Wood: In southern Africa, representatives of only six genera
are classified as trees, but the wood of only two genera, wild silver
oaks (Brachylaena species)
and wild camphor trees (Tarchonanthus
species), have been reported as being used for building huts,
fence posts, handles of utensils and turnery.
Garden
plants and cut flowers: Did you know that the edelweiss (Leontopodium
alpinum) that acquired fame in the musical The sound of music,
belongs to the family Asteraceae? The most well-known daisy South
Africa gave the world, is the Barberton daisy (Gerbera spp.)
Today there are many varieties and cultivars available on the market.
Familiar cutflowers are asters, dahlias, chrysanthemums, cornflowers
and sunflowers, The full potential of South African daisies for
gardening has not been exploited yet. There are many different South
African species that can be cultivated successfully. Those that
have featured in this series include:
Arctotis arctotoides
Athanasia dentata
Cineraria saxifraga
Dimorphotheca pluvialis
Dimorphotheca sinuata
Euryops virgineus
Felicia echinata
Felicia heterophylla
Gerbera aurantiaca
Gebera jamesonii
Helichrysum umbraculigerum
Helichrysum splendidum
Kleinia fulgens
Oldenburgia grandis
Senecio macroglossus
Senecio elegans
Ursinia cakilefolia
Vernonia hirsuta
Please use the site search facility to find others (Enter Asteraceae
as the search term).
It is important to plant daisies in full sun or where they will
receive sun for at least half the day to ensure that the 'flowers'
will open to their full glory. They are normally easy to grow and
do not need much attention.
References
- Bremer, K. 1994. Asteraceae, cladistics and classification.
Timber Press, Portland, Oregon.
- Herman, P.P.J. 2000. Die familie Asteraceae: 'n Algemene oorsig.
Suid Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie
19: 66, 67.
- Herman, P.P.J. 2000. Die plantfamilie Asteraceae: 2. Die blomme.
Suid Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie
19: 118-121.
- Herman, P.P.J. 2002. Die plantfamilie Asteraceae: 3. Die vrug.
Suid Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie
21: 19-21.
- Herman, P.P.J. 2002. Die plantfamilie Asteraceae: 4. Interessante
groeivorme en ekonomies belangrike soorte. Suid-Afrikaanse
Tydskrif vir Natuurwetenskap en Tegnologie 21: 108-110.
- Herman, P.P.J. 2003. Die plantfamilie Asteraceae: 5. Klassifikasie
en die subfamilie Cichorioideae. Suid Afrikaanse Tydskrif vir
Natuurwetenskap en Tegnologie 22: 45-49.
- Herman, P.P.J., Retief, E., Koekemoer, M. & Welman, W.G.
2000. Asteraceae. In O.A. Leistner, Seed plants of southern Africa:
families and genera. Strelitzia 10: 101-170. National Botanical
Institute, Pretoria.
- Vahrmeijer, J. 1981. Gifplante van Suider-Afrika wat veeverliese
veroorsaak./Poisonous plants of southern Africa that cause stock
losses. Tafelberg, Kaapstad.
- Van Breda, P.A.B. & Barnard, S.A. 1991. 100 Veldplante
van die Winterreënstreek. 'n Gids vir die benutting van veldplante
vir weiding./100 Veld plants of the winter rainfall region. A
guide to the use of veld plants for grazing. Department of
Agricultural Development, Pretoria.
- Van Wyk, B-E., Van Oudtshoorn, B. & Gericke, N. 1997. Medicinal
plants of South Africa. Briza Publications, Pretoria.
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Author
P.P.J. Herman
National Herbarium, Pretoria
April 2004
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