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Readers are invited to submit short items of interest about Australian plants to be included here. If submitting non-original material (eg newspaper or magazine cuttings), please also advise if the author has given permission to republish and, if not, please provide a contact address so that permission can be sought.
Short Cuts in this issue:
- Growing Grasses
- Native grasses have a place in the Australian landscape.
- The Ranunculus Family - at home in the rain
- Australia has a good representation in this family...you may even know some!
- Autumn - A Time to Rejuvenate the Garden
- Cooler weather means that there's no excuse for any more procrastination!
- Mycorrhizas in the Australian Flora
- Not all fungi are pathogenic....some have a role in plant nutrition and health.
- Protecting the Wee Jasper Grevillea
- Grevillea iaspicula grows in a restricted area of central western New South Wales.
- The genus Lomatia
- Ever heard of Lomatia? This Australian and South American genus in the Protea family is sadly neglected by growers.
Grasses are not just meant for lawns! A native garden can benefit from incorporating native grasses into the landscape as Pat Tratt reports......
When looking around your garden consider where you might incorporate a few native grasses or a grassy area. Perhaps a few plants under trees or in a bare dryish area - weeping grass, Microlaena stipoides or slender wallaby grass, Danthonia penicillata are two that are suitable. Just a couple of plants will self-sow to produce a natural look with scattered cover.
Grasses have many uses and I believe no landscape is complete without some. I like creating grassy areas with spaces between interplanted with typical grassland herbs and forbs. They gain some shelter and light shade from the grasses, particularly those with fine inflorescences such as Eragrostis truchycarpa or Stipa elegantissima. Poa species and other large tussocks can smother more delicate plants so leave good spaces to interplant. When first planted out a couple of grassy leaves don't look much, but they grow rapidly and expand. I find it useful to push a small stick in the ground beside new plants as a reminder not to weed them out. You might be able to obtain local grasses from your nursery or why not try growing some of your own from seed (see below - ed). Themeda triandra (syn T.australis) (kangaroo grass) makes attractive tussocks for open grassland. Your plan can be for just a small area or larger spaces. Grasses are adaptable and you can find species for moist depressions, drier areas, under trees, etc.
Any seed raising mix you find successful can be used. I put a good layer of propagating sand on top. Sow the seeds thinly as they come - some have parts of the floret attached. Leave any awns on. Pick a mixed bunch of inflorescences when young to display in a vase. They look very elegant. In your landscape, trim off seed heads once they change colour and mature if you don't want seedlings at random. This will stimulate new green growth and fresh inflorescences. I don't trim green basal leaves of any grasses, but any old dead matter can usually be removed by pulling your fingers through the clump (with gloves on as garden spiders often lay their eggs in the tussocks). Some tougher leaves such as those on some Poa species need to be trimmed with shears to remove old leaves as much of the dead growth will sprawl over the ground and smother smaller species interplanted.
The following grasses require little maintenance, don't need watering once established and provide a soft naturalness to landscapes, big or small.
Stipa verticillata (slender bamboo grass)
As its common name suggests, it forms a large graceful clump. Germination is usually good. Adaptable, will grow in clay.
Stipa elegantissima (feather spear grass)
Forms a rhizomatous tussock with a very pretty feathery inflorescence. Likes a sandy friable soil. Germination can be erratic.
Dichanthium sericeum (silky blue-grass)
Eragrostis trachycarpa (rough grain love-grass)
This is a smaller tufted upright grass with eye-catching blue-grey leaves and an attractive inflorescence to use indoors, cut when young before they shatter. Grows readily from seed and is adaptable to dryish sites, clay or moist well drained sites.
This is one of my favourites. The small basal tuft is a yellowish-green and the inflorescence is a wide spreading panicle, very fine and giving quite a misty almost airy appearance. Likes moist depressions but will grow on drier sites.
Danthonia longifolia (wallaby grass)
This can produce a vigorous dark green basal tussock of fine leaves with some red tinges in moist well drained sites, or a sparse tuft of finely inrolled flexuose leaves with reddish colouring, on drier ground. It is commonly found on drier rocky sites. The immature heads are attractive and later develop the straw-colour typical of wallaby grasses.
Some species for interplanting I find effective are Arthropodium strictum, A.milleflorum, Bulbine bulboa, Dianella species, Diplarrena moraea, Patersonia species and Tricoryne elatior. Many of the brachyscomes do well, as do Wahlenbergia species and low growing pea flowers, plus many other species common to grasslands.
From the September 1997 issue of the newsletter of the Victorian Region of the Society for Growing Australian Plants.
Seeds of Australian grasses can be obtained from commercial suppliers of Australian native plants.
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At Home in the Rain
Betty Ballingall sheds some light on the Ranunculaceae....the family of "little frogs"
A brief look at Clematis microphylla reveals some interesting botanical features, such as the leaf stalk or petiole acting as a climbing support, and the free or separate carpels (ovule-bearing unit with a style and stigma) called an apocarpel gynoecium, the female part of the flower. Most Australian plants have a syncarpous gynoecium in which the carpels are fused together. However, there is probably another surprise on discovering it belongs to the family Ranunculaceae.
A climbing plant with creamy, star-shaped flowers seems quite at odds with the Ranunculus, which usually have flowers with broad, glossy, golden petals, and are commonly known as buttercups; or even more odd if you compare it with the garden plant, Aquilegia, the columbine or granny's bonnets. In fact the family is known for its variety of habits.
The Ranunculus family (Ranunculaceae) is regarded as primitive and is one of the very few families known to feature rain pollination. The European species, Ranunculus repens, is reported to remain open on rainy days; the water running down the glossy petals dislodges the pollen and carries it to the base of the corolla, where it then rises through the carpels to deposit pollen on the stigma.
Ranunculus is Latin for "little frog" or tadpole, which suggests the species is often found in boggy or aquatic habitats. In fact, many species do grow in the coldest, wet places, such as the snow fields of both hemispheres. Of the 1800 species and 50 genera worldwide, Australia has 5 genera with approximately 39 species and 2 naturalised genera.
|"The Ranunculus family.......is regarded as primitive and is one of the very few families known to feature rain pollination."|
Clematis grows in drier habitats than most other species. The female plant grows the beard. The white plumose style persists and the plant becomes covered in shiny white stuff, giving it the common name, Old Man's Beard, or you can have Headache Vine or Traveller's Joy. The male plant growing over a stump in my garden is a picture, with its mass of cream flowers. I am searching for Clematis fawcettii, a species rare in Queensland, which is required by a Canberra botanist who is studying the genus. It has deeply lobed leaflets with serrate margins.
There are 400 species of Ranunculus throughout the world with about 30 native and 4 naturalised species in Australia. They like areas beside creeks or other damp places. Some of the showiest species grow on the snowfields of the Australian Alps.
Ranunculus graniticola is known as the granite buttercup and occurs in sub-alpine areas. Select the thumbnail image or plant name for a higher resolution image (38k).
Caltha is another unusual genus and is generally regarded as one of the most primitive genera of the family. Alpine Marshmallow, C.introloba, grows at Kosciusko on short alpine herbfields. It is found below snow patches and in shallow snow-melt streams. The white flowers open while still covered with snow. After flowering, the peduncle lengthens and the shiny, pale brown follicles are flower-like.
Australia has one native anemone, which is endemic in Tasmania. Mousetails, Myosurus minimum, emphasises the variety of habit in the family. It is a small herb with tiny greenish flowers. As the flowers fade, the receptacle appears bearing the slender green 'mouse-tail'.
I first found the naturalised Adonis microcarpus along the roadside south of Glenmorgan and collected a few plants; so they now come up in my garden. These bright Pheasant's Eyes have red petals with a dark spot at the base and blackish-purple anthers. The light green ferny leaves are attractive too. Like some of us, they have immigrated from southern Europe.
Some other genera popular as garden plants include Aquilegia, Delphinium, Anemone and Hellebores. A few poisonous members occur, among them the genus Aconitum or Monkshood.
From the September 1990 newsletter of the Toowoomba Group of the Society for Growing Australian Plants.
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Autumn - A Time to Rejuvenate the Garden
Gwen and Rodger Elliot have some suggestions to help lift your garden out of the doldrums. Now is the time to act!!!
As we enter autumn it is often beneficial to look back over the past summer and consider the state of our gardens at this time of year.
Firstly were we content with the display of foliage and flower over the summer period? If we were that's fine, but if we have some doubts now is the time to act. If we don't the time will pass and when next summer is here we will be saying "Why didn't I do something about the summer appearance of my garden last autumn?"
Autumn is the ideal time to organise the removal of unsatisfactory plants and to replace them or add further plants which you feel will have functional value and provide you with visual pleasure.
It is good to keep in mind the importance of summer shade and the likely impact of sunless winter days. Remember you also have neighbours who might treasure any winter sun that is available too. Thoughtless plantings close to a boundary fence could deny them this pleasure.
Secondly, we can consider our gardens during the autumn season, and judge whether their performance is up to our expectations as far as foliage and flower are concerned. There are many plants which have special attributes during summer and autumn, and a few have been selected for discussion here. Some are well-known, regularly reliable plants and have been in cultivation for ages, whereas others are relatively new to the horticultural scene and you may even have to hunt around through nurseries in order to obtain plants. Alternatively you may be able to obtain cuttings or seed and propagate your own plants.
The quick-growing, low, suckering Helichrysum amplexans from Queensland is a golden joy for most of the year, but it reaches its peak in summer and autumn. You can soon develop informal drifts and colonies by transplanting divisions which respond well and become quickly established.
A pleasing combination with the above is Scaevola albida (from Qld, NSW, Vic and SA) which can have white, pale mauve to pale blue flowers and forms a low rounded mound (it is easily confused with Scaevola pallida which has a non-hairy style). This species is sometimes overlooked in preference for Scaevola species 'Mauve Clusters' which has larger flowers with a deeper colour.
If you have a love of perfumed plants then try growing Stackhousia monogyna from Qld, NSW, Vic, Tas and SA. Its delicate sweet fragrance is most pervasive in the evenings. It is a most variable species, sometimes developing as an open, sprawling or suckering plant, but other forms are compact, some even shrub-like. Variations also occur in the candle-like flower spikes. They are usually white to cream but there are forms with beautiful soft pink tonings at the bud stage.
Select the thumbnail image or plant name for a higher resolution image (25k).
We have a form from south of Bodalla (SE NSW) which has been flowering from early October and continues to produce flower-heads of about 4cm in length on stems which are now (February) around 35cm long. It is also an excellent cut flower. Cutting it back to near ground level in late summer to early autumn rejuvenates the plant.
Foliage plants which to me are a delight are Leptospermum brevipes and L.obovatum. The former is a graceful, slightly pendulous tall shrub to small tree of about 4-6m or so. In spring it has a massed display of faintly pink-tinged white flowers, and in summer and autumn the foliage attains dull burgundy tonings. The forms we have originated in East Gippsland but it also occurs in other areas of Vic, Qld and NSW. L.obovatum from NSW and Vic is more stiff in appearance but it has a slightly deeper burgundy foliage coloration which it retains for 8-9 months of the year. In early summer the sizeable cream flowers are profuse. Both these species are ideally grown as plants on trunks, by the gradual removal of the lowest branches. Both species are enhanced when grown in informal copses. Don't be afraid to have some as close as 30-45cm to each other. You can create a delightful mini-forest in this way.
Most readers will be familiar with the blue-flowered bell-climber, Sollya heterophylla (which, by the way, is becoming entrenched as an environmental weed in some parts of Victoria especially on the Mornington Peninsula because the seeds are distributed by birds - we need to be very much aware of the consequences of introducing to certain regions, plants which may prove to be serious problems). Another blue-flowered climber, which is a fairly recent introduction to cultivation is Billardiera drummondonia var. collina from the Darling Range in WA. It has bright blue tubular flowers with 5 spreading lobes. They are produced mainly over spring and autumn, or in some cases nearly all year. It has slender twining stems which are not as thick as those of Sollya heterophylla. Keep a watch out for plants; they will become very popular.
Clumping plants always add a different texture to gardens and Glischrocaryon behrii, commonly known as golden pennants, is excellent value with its erect, apparently leafless stems. During spring, summer and early autumn the display of small greenish-yellow flowers can be very rewarding. Perhaps some of you will have seen this species in all its glory when you have visited the Whipstick area near Bendigo in early to mid-spring. It is also found in NSW and SA. Plants prefer plenty of sunshine but will tolerate a semi-shaded position.
For groundcoverings, Hemiandra pungens from WA is hard to surpass for length of flowering period and for density of floral display. There are quite a number of forms now available. Two fine foliaged forms are well-entrenched, one has mauve-pink flowers and the other white. They really provide a most attractive sight when grown in combination. The large mauve-pink flowered form is not as floriferous, but is nevertheless excellent value for relatively large areas.
Select the thumbnail image or plant name for a higher resolution image (29k).
Hemiandra pungens appreciates good drainage and grows best where aeration is at an optimum between the foliage and soil. Growing it in conjunction with boulders and logs is often beneficial.
A very beautiful plant which is worth seeking is Commersonia pulchella (also from WA). It always seems to be producing some of its small, dainty white and pink, open-petalled flowers. Summer and autumn periods are no exception,as the display is certainly most noticeable during that time. The rusty hairy stems of new growth and crinkled leaves are also attractive. Once established it will produce sucker growth and plants are readily rejuvenated by the removal of old wood to near ground level.
For people who like bold colours Beaufortia purpurea from WA with its purple-red pom poms over the summer and autumn months is certainly hard to surpass. When we grew this species originally it was said to grow as a dwarf plant. Experience has taught that this is not so. It may reach 2m x 2m but it usually does not exceed 1.5 m in height. Pruning after flowering is strongly recommended if you wish to promote bushy growth.
A few jobs to contemplate during late autumn include the dividing of kangaroo paws and the closely related Conostylis species. Kangaroo paws don't usually provide much of a problem and results are not usually traumatic, but Conostylis can be a different story. A hint when dividing these is not to be too greedy. Always err on the heavier side as far as the size of divisions. You are likely to achieve better results.
From the March 1986 issue of the newsletter of the Victorian Region of the Society for Growing Australian Plants.
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Mycorrhizas in the Australian Flora
Brett Robinson looks at the association between plants and fungi....or is he on a quest for the Australian truffle?
What mycorrhizas aren't.
- They aren't clusters of proteoid roots that grevilleas and banksias use to survive in very poor soils.
- They aren't root nodules like the legumes, casuarinas and cycads have to extract nutrition (nitrogen) from the air.
Mycorrhizas are an association between plant roots and a fungus. The association is usually (as far as we know) beneficial to both. Most Acacia, Casuarina and Eucalyptus species are mycorrhizal. Some species are unable to grow and develop without their fungal associates. Many of the Alphitonia, Lobelia and Pratia are like this.
There are several types of mycorrhizas. Probably the largest in terms of numbers and most widely spread group are the vesicular-arbuscular mycorrhizas (VAM). We now know that the vast majority of plants (thousands of genera) form VAM but only with a relatively small group of fungi (a few genera only). Other types of mycorrhizas are the orchid and ericoid mycorrhizas and a diverse bunch called the ectomycorrhizas. Orchids and ericas are usually dependent on their fungal associates.
That's why my Ricinocarpos cuttings never worked. The ectomycorrhizas (ecto - outside) have a sheath of which envelops the roots. They are very common in the Australian flora, including genera such as Acacia, Casuarina, Eucalyptus, Melaleuca and Nothofagus.
Mycorrhizas of all types are enormously beneficial to plants growing in soils of poor fertility. In fact, even where many native plants grow very well, non-mycorrhizal plants may barely survive. Because the fungus consists of very fine threads in the soil, it is able to seek out and absorb (and even digest) nutrients that plant roots can't get to. (Just leave a loaf of bread out to go mouldy and you will get an idea of how voracious a fungus can be). Up to 5000 metres of fugal threads can be found in just one handful of soil. This great mat of threads is especially useful for scavenging phosphorus from the soil because phosphorus is bound to each soil mineral or humus particle. Plant roots could never be so abundant that they would contact each particle in the soil. The fungus swaps nutrients for simple sugars from the roots. This helps the fungus grow and propagate.
Mycorrhizas are also known to protect plants from various pests and diseases. For example, nematodes are thought to be repelled from some ectomycorrhizal plants by the fungal sheath around the roots, which forms an effective physical and chemical barrier to infection. Our knowledge of these types of interactions of soil microbes and their role in plant health is steadily increasing.
PS: The reference to truffles in the introduction is because truffles are the fruiting body of a fungus (Tuber) mycorrhizal with oak (Quercus) trees. Over the years there have been vague reports of truffles in native plant communities (especially in Tasmania).
From the June/July 1990 issue of the newsletter of the Newcastle Group of the Society for Growing Australian Plants.
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Protecting the Wee Jasper Grevillea
The small population of this species is subject to a number of threats. However, landholders and conservation groups have combined their efforts to maximize its long term chance of survival.
The future of the endangered Grevillea iaspicula which is restricted to the Wee Jasper area, about 40 km north west of Canberra, is looking much brighter following the combined efforts of a small group of landholders and conservation agencies.
The survival of Grevillea iaspicula depends on effective land use control. Select the thumbnail image or plant name for a higher resolution image (27k).
The plant is the focus of the Wee Jasper Grevillea Recovery Team which involves four landowners, the local school teacher, and representatives from the Society for Growing Australian Plants, the Goobarragandra-Goodradigbee Reserve Trust, Burrinjuck State Recreation Area, NSW National Parks & Wildlife Service, the Biodiversity Group of Environment Australia and the NSW Department of Land and Water Conservation.
There are less than 250 mature plants in the wild which are subject to grazing by domestic stock, feral goats and blackberry and sweet briar weed infestation. Many of the plants only survive in precipitous inaccessible locations. Recently, all significant colonies of Grevillea iaspicula were fenced off from grazing animals and extensive control of weed infestations has been completed. Annual monitoring of the populations will provide important information about the effectiveness of recovery actions and in particular, the recruitment of seedlings.
The cost to date is $18,000.
From the November 1997 issue of the newsletter of the Grevillea Study Group, reporting on an article in the June 1997 issue of "Danthonia".
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The genus Lomatia
Lomatia is one of the less well known members of the Australian Proteaceae. Marilyn Gray explains why they are deserving of wider cultivation.
Lomatias belong to a small genus of twelve species in the family Proteaceae. They have
a disjunct distribution with nine species found along the east coast of Australia and the remaining three species occurring in Chile in South America. The world "Lomatia" is derived from the Greek word loma meaning a border or fringe and refers to the papery wing surrounding each seed.
Karwarra Garden in Kalorama, east of Melbourne, is currently growing all nine species of Lomatia and has applied to the Ornamental Plant Collections Association for registration of the genus collection. Several variations can sometimes make it difficult to decide whether a plant is a species or a hybrid. Hybridisation occurs both in nature and at Karwarra with recent seedlings proving to be L.myricoides x fraseri.
Lomatia species are a relatively unknown and uncultivated group of plants deserving much wider recognition. Most appear to be hardy at Karwarra, the exception being L.ilicifolia which actually occurs naturally nearby! They have much to offer the home gardener with most species tolerant of both shade and sunshine, preferring moist, well drained soils. Tip pruning from an early age encourages bushiness while those species forming lignotubers will tolerate quite hard pruning. The latter species, including L.ilicifolia, reshoot after fire, flowering profusely that season.
Like many of the genus, Lomatia myricoides is not seen in cultivation as often as it deserves. Select the thumbnail image or plant name for a higher resolution image (43k).
Lomatias are shrubs or small trees mostly occurring in forests. The flowers, which are superficially similar to grevilleas, are usually white to cream, fragrant and well displayed in auxiliary or terminal racemes. They have the added bonus of being summer flowering. The fruit is an interesting leathery follicle containing two rows of overlapping seeds which germinate readily, especially if they are fresh. Leaves may be entire but are more usually toothed or lobed.
Three species of Lomatia are endemic to Tasmania, these being L.polymorpha, L.tasmanica and L.tinctoria. Karwarra grows three different forms of L.tinctoria, the foliage differing markedly, varying from a very broad leaf to a fine bipinnate form. Our most recent addition is L.tasmanica, a rare plant which is difficult to grow in cultivation. It differs from all other species in that the flowers are red. Our plant has been grafted to L.tinctoria and is growing slowly.
The three species of Lomatia occurring in the Melbourne region also grow in New South Wales. L.fraseri and L. myricoides have proved very reliable at Karwarra, flowering profusely each year. L.myricoides has long, narrow leaves while the foliage of L.fraseri is quite variable. L.ilicifolia is a smaller shrub with holly-like leaves.
L.silaifolia is a dwarf to small shrub with many foliage variants. We grow two variants, both of which are quite slow. Leaves from this species have been glycerined to provide interesting cut foliage (other species would also be most attractive when used this way). Another species which occurs in both NSW and Queensland is L.arborescens. Several plants were established in the rainforest section here three years ago and are progressing well. They should ultimately grow into small trees.
The final Australian species is L.fraxinifolia, endemic to the Queensland rainforest. It is similar to a form of L.silaifolia but has much larger leaves. Leaflets are also less uniform in size and shape.
I would encourage you to consider a Lomatia when looking for something a little less usual. When you are in Melbourne, visit Karwarra and have a look at them before you buy. Some species will be hard to find in the nursery so you may need to ask, but they are not difficult to propagate. Try some seed or put in some cuttings and be surprised by a new group from the well known Proteaceae family.
From the September 1994 issue of the newsletter of the Victorian Region of the Society for Growing Australian Plants.
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Australian Plants online - March 1998
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