How to use this book
T his book
describes and illustrates plant species that are weeds in
Western Australia. Most of them have been introduced to the
State, but a few are native plants that have expanded their
ranges as a result of human activity or have become weeds of
cultivation. In the main part
of the text the weeds are listed under four major groups:
Ferns - Gymnosperms (conifers) - Monocotyledons (lilies,
grasses, sedges) and Dicotyledons (other flowering plants).
Within each group, the plants are organised into botanical
families that are arranged alphabetically, and within each
family the weeds are arranged alphabetically by their genus
and species names. A list of introduced species that are
doubtfully naturalised is included as Appendix B.
Most of the common or more noticeable species have been
illustrated. The descriptions concentrate on the characters
that distinguish a species from closely-related ones, but
also include distribution information, flowering time and
region of origin. It should be possible to identify most of
the species using this information, but within some groups
of related species (such as sedges) it is very difficult to
identify individual species with certainty, and the reader
is referred to specialist texts that are listed in Appendix
C. A
glossary of botanical terms will be found at the rear of the
text.
Cape tulip in a paddock near York. PH
Identification and collection of weed specimens
By referring to the illustrations and descriptions in this book, it will be possible to identify most of the weeds found in most parts of the State. Garden centres and agricultural retailers can also help identify many common weeds. Sometimes, however, weeds will be found that can not be identified this way, because they are not illustrated or described, or because they might be new to the State. If you are still unable to identify a particular weed, it might be necessary to collect a specimen of a plant for exact identification. A piece containing flowers, fruits and leaves is most helpful, and it should be the size of a newspaper page and pressed under weight (or several specimens to make up the page if it is a small plant). Press two specimens, one for sending to an expert, and one to be retained by you. Make notes - as detailed as possible - about each specimen. Contact the Weed Science group of Agriculture Western Australia (if the weeds are from agricultural or pastoral land) or the Agwest Garden Advisory Centre (if a garden weed) - a small fee for service may apply for identification and further information. Over 30 local herbaria exist in Western Australia, run by community volunteers, and most will be delighted to help you with identification. These local herbaria will liaise with the Weed Science group and the Western Australian Herbarium in Perth on your behalf, and will keep your specimen as a permanent record of plant distribution in the local area.
Weeds from agricultural and pastoral land should be identified through Agriculture Western Australia; take the specimen to their nearest office.
Please note that regulations regarding plant collection apply, and a licence may be necessary. Consult the Department of Conservation and Land Management for details.
A note on the taxonomy
Giving accurate
names to living things is called taxonomy. A plant is first
classified into a family (e.g. Asteraceae, the daisy
family), then into a genus that has a Latinised name
starting with a capital letter (e.g. Helianthus, the
sunflower genus) and finally into individual species which
are indicated by the second Latinised name (e.g.
Helianthus annuus, sunflower and Helianthus
tuberosus, Jerusalem artichoke). In botanical texts this
name is followed by an abbreviated version of the name of
the botanist who first described the plant (e.g.
Helianthus annuus L. that stands for the Swedish
naturalist Linnaeus, 1707-78). The name of the botanist is
omitted from this book, as being irrelevant to most
readers. Ongoing
taxonomic research sometimes causes names to be changed.
Where this has happened recently, the name formerly applied
to that plant is given in brackets. Photographs, taxonomy
and textual information are based on specimens contained
within the Western Australian Herbarium, and are as correct
as the authors can determine at the time of going to
press.
Ground layer dominated by weeds: lupins, sousob, cornflag
and wild oats, Gooseberry hill. PH
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