NATIVE PLANT OF THE MONTH FOR JANUARY 2010
DELIGHTFUL DAISIES
What is the common link between the following: sunflowers, lettuce, chrysanthemum, dahlia and artichoke? If you said they are all members of the daisy family then you are right. This huge family, with the scientific name Asteraceae, contains something like 20000 species worldwide, in about 1000 genera and includes many species of economic importance (and some of the worst weeds).
The former family name, “Compositae”, provided a clue to the characteristic feature of these plants, which is that all of them have composite flower heads. What we think of as the flower is actually a cluster of tiny flowers (known as florettes) in some species only a small number but in others, such as the cultivated sunflower, hundreds of florettes. You can see the individual florettes if you use a magnifying glass or microscope. Each of the tiny florettes produces its own seed which is often attached to a feathery pappus which everyone knows as thistle down (see insert in photo). The pappus along with the attached seed is capable of travelling long distances when a wind is blowing, which explains why many members of this family can spread so quickly.
In Tasmania there are dozens of native members of this family, ranging from quite large trees to tiny herbs. In between these extremes there are medium size shrubs and several beautiful species which would be described as paper daisies.
The flower heads of these paper daisies range in size from just under a centimetre in diameter to about 4cm diameter. Their colours in the Tasmanian species are white or golden yellow but many of the buds are also attractively coloured e.g. pink or orange.
Paper daisies are generally very hardy, as indicated by the fact that large colonies of some native species survive along our roadsides, flowering for long periods in spring and summer in some very harsh environments.
Some species can be induced to flower twice in one year by cutting them back after the first flowering is completed.
Propagation is easy from seed – just collect the thistle down before it flies away, making sure that the seeds are still attached. By buying just a few plants from a nursery and propagating from these you can have a wonderful display within a couple of years.
(The species shown in the photo is Xerochrysum bracteatum or golden everlasting which has flower heads up to about 4cm across. The inset shows the feathery pappus with the seed attached below it.) |