Sunday, January 15, 2017

Blotched Hyacinth Orchid

Dipodium variegatum
 Most of our local orchids flower in spring, but there are a few exceptions. Hyacinth orchids do it in high summer, usually after rain, as with this one which I saw yesterday.

The common name of this plant seems a misnomer to people who know other hyacinth orchid species as well. They are all blotched!

This one is more blotched than the others, though. Notice that the blotches extend to the flower stem (the pedicel and ovary) which doesn’t happen with the others.

It’s always a pleasure to find a hyacinth orchid, as they can’t be grown. They occur only where they’ve planted themselves, and I’ve never heard of one choosing to come up in a garden.
This plant was living in the typical habitat of the species, which is open eucalypt forest with a light grassy understorey. Most of its life is spent completely underground. It only puts up flowering stems once a year, when it’s time to try for babies. A flourishing plant might put up three or four stems.

This flower has its "tongue" hanging out, hoping for a native bee or wasp to be tricked by its bright colours into thinking it will find nectar here so it can be roped into the job of pollination. Like most orchids, it's a cheat. It has evolved to look like a nectar-producing flower, but makes no nectar. It takes a lot of energy to make nectar, and this plant is a miser where energy is concerned.

Hyacinth orchids don’t do leaves. They are often described as parasites or saprophytes (the latter meaning meaning plants that get their nutrition and energy from decaying matter under the ground). rather than the usual method, which is to make it in leaves by photosynthesis.

Saprophytes are not the same thing as parasites. Parasites live on other living organisms. Saprophytes live on plant material which is already dead. They are usually  bacteria and fungi, and are an important part of the growth and decay cycle of their ecosystem, breaking down dead material and making it available for re-use by other plants.

Strictly speaking, hyacinth orchids are neither parasites nor saprophytes. They are myco-heterotrophs, which means that they attach their roots to a  mycorrhizal fungus which is the true saprophyte, living on dead eucalypt roots.  Most myco-heterotrophs live in partnership with their fungi. They take some nutriment from them, but also photosynthetise, making carbohydrate which they share with their fungus hosts. Despite their lack of leaves, hyacinth orchids do photosynthise. Those green stems are doing the job. But considering the short life of the flower on what is a perennial underground plant, I suspect that the fungus is the partner that does most of the work.
(A few plant species of myco-heterotroph are 100% parasitic. These are the ones that have no green on them at all, such as or local bootlace orchid,  Erythrorchis cassythoides.)

To grow hyacinth orchids, all we need is some land with an open eucalypt forest ecology (complete with its cycle of growth and decay), some relatively open grassland, and the right species of fungus. Nature does it without apparent effort, but we humans have not managed to copy it.

 We have still not invented anything as clever as a plant.


Sunday, January 1, 2017

Tree Root Problems

Trouble with foundations, sewer and water wipes, footpaths, fences?
   I would like to know what other people’s experiences are. There must be a lot of knowledge out there about Australian native plants growing near built structures, but it’s hard to find it.
I got curious about the subject because one of my readers asked about about her kurrajong Brachychiton populneus. She has it planted 10 feet (3 metres) from a porch. Her husband wants it removed, as he is worried that it might affect the foundations. She would like to believe that it is far enough away to be of no concern.
   I would have thought 10 feet was far enough. This is a drought hardy tree which has evolved to survive by putting its roots deep, unlike Brachychitons from wetter parts of Australia, which might have shallower roots and be more of a problem.  

The owners of this house at Inglewood didn't seem to have any problems with their kurrajong, and it looks as though both house and tree have been there a long time. What wonderful shade it gives, on a hot summer's afternoon.
   I went looking on the internet, thinking recommendations for suitable distance from structures, for planting various species, would be easy to find.
   Not so!
   I found various lists of recommendations, but the differences between them were so great as to be ludicrous.
   In the case of the kurrajong, I found that Western Water (a water authority near Melbourne, which surely cares that its users don’t wreck their pipes with careless planting), lists kurrajong as one of its "acceptable plants near sewer lines" so long at it is 2 metres away from the pipes. It is interesting that they don't list any other Brachychitons as "suitable".
    The Australian Plant Society recommends the kurrajongs should be placed 3.5 metres away (the same recommendation as it makes for some other, less drought hardy Brachychitons. Are they really all the same?) An East Gippsland site thinks they should be 4 metres away. A Western Australian water corporation recommends 6 metres. Bundaberg Regional Council doesn't think they are safe unless they are 10 metres away. One site makes a blanket recommendation that all trees should be planted a distance 1-1.5 times the potential, full-grown height of the tree away from all structures! 
   What boring places our suburban gardens would be if we all took his advice.

   So what is your ordinary person to make of this? Do these people really know their stuff? If so, which ones? They can't all be right.
   Well there are some obvious clues that let us know which advice we should take with a grain of salt. Clues to the clueless are:
a. They have a blanket rule for all trees, whether or not they are species which would really be surrounded by a wide circle of shallow roots equal to the tree's height (possible with Eucalyptus trees) or more likely to have roots which plunge deep in a narrow root-zone, (like dry rainforest species).
b. They don't supply botanical names, so you can be left in doubt as to which plant they are talking about. If they do give a botanical name, it is the name of the genus only, and then we are warned against the lot as if they were all the same. No, a little Meleleuca thymifolia is NOT going to cause the same problems as a whopping Meleleuca quinquenervia. To say that "Melaleuca sp." should be kept more than 6m away from drains is not helpful!
c. They seem to be written by someone who doesn't know much about plants, but knows that he/she will suffer consequences, if the distance recommended is not big enough. Huge margins of safety probably indicate a less reliable site.
   Sadly, advice provided on these ill-informed sites must have caused the destruction of  many harmless plants. They are certainly no help to those of us who like plants in our gardens. We can't help but be very well aware that many of the plants that they warn us against are growing in gardens around us, causing no problems at all.

I did find some sites which looked as though they had been written by people who knew their stuff.
   The best of them seemed to me to be East Gippsland Water, at  , and the Australian Plants Society’s Drain Cloggers page, at
   However, even the best sites suffered from plant lists which were too small to be broadly helpful. Better to be silent than to spread misinformation, of course, but we could do with more, and more reliable, information on the performance of a wider range of Australian native species near built structures.

Can you help? 
   I would love to hear from experienced gardeners who live with gardens containing Australian native trees and shrubs, and are prepared to share the knowledge they have gained from practical experience. 
  I feel sure there would be readers who  would like to hear it, too.
   I don’t just want to know about the problems, though that certainly helps. I also want to know what plants can tentatively be classified as not too risky. What grows close to your house / footpath / drive / water-carrying pipes, and seems to be problem-free? 
   Please see my email address in the white column at right. I’d love to hear from you!
Or write a comment, but be warned that when you publish it, it won't appear at once.  I screen all comments first, and don't do it every day.

Saturday, December 31, 2016

Dry Rainforest Trees

Suitable for Gardens

Auranticarpa rhombifolia

Not all “rainforest" trees are the same. As a general rule, the wetter the rainforest type, the more likely its plants are to have evolved  shallow root systems. Trees of typical rainforests are likely to be problematical if planted close to buildings, driveways, paths, and drains. Many of them are also too large to be suitable for suburban gardens.
“Dry Rainforest” plants are their drought-hardy relatives. Unlike the plants of wetter rainforests, they can’t count on getting regular rainfall. The secret of their survival in their drought-prone native habitats is their tendency to put down deep roots as fast as they can, to find water deep underground.
They tend to be smaller trees than their big rainforest relatives.
They also prune well.
These three habits make them very garden-friendly.
1. Their deep-rooting habit means that they don’t make much use of the upper layers of soil. They can be planted close together, and are happy to share the space in the upper layers of the soil where most small garden plants want their roots to be. They are also less likely to damage paths, driveways, house foundations, and to send their little roots into our pipes and sewers. (Yes, of course they will do damage if you tempt them by planting them right next to a leaky pipe, or place a large plant smack up against a brick wall. Use some commonsense here! Think low-risk, not no-risk. No-risk means a garden of concrete and plastic plants.)
2. Their smaller size means that we can grow nice shady trees which won’t outgrow our suburban-sized gardens.

Denhamia bilocularis

3. Their adaptability to shaping and pruning means that they make good hedges or dense shrubs if pruned to the size of your choice. Cutting them back hard encourages the formation of multiple trunks. They can also left (or encouraged) to grow as shady little single-trunked trees. Trim the lower branches a bit, and you have a spot for a bird bath or a garden seat.
Too many trees? No problem! Cut some off at the ankles and let them regrow as multi-trunked shrubs.

Notelaea microcarpa

4. And their drought hardiness means that once established they will live a normal lifespan, possibly hundreds of years, without ever needing more rainfall than our erratic climate gives them. Like most plants, they appreciate extra water, especially in winter or dry times when their natural habit is to drop some of their leaves to conserve water. Watering keeps them dense and shady - but those who can’t manage the water can just wait it out. When the rains start, their canopies will thicken up again.

Some of our Local Dry Rainforest Trees:

Acmena smithii (Syzygium smithii) LILLYPILLY, COMMON  
Acronychia laevis ACRYONYCHIA, GLOSSY  
Alangium villosum MUSKHEART, BLACK  
Alectryon diversifolius BOONAREE, SCRUB   
Alectryon pubescens BOONAREE, HAIRY  
Alectryon subcinereus BIRDS EYE, QUINCE LEAFED  
Alectryon subdentatus BIRDS EYE, HOLLY LEAFED   
Alectryon tomentosus BIRDS EYE, HAIRY  
Alectryon tomentosus BIRDS EYE, HAIRY  
Alectryon connatus BIRDS' EYE, COMMON  
Alectryon oleifolium ROSEWOOD, WESTERN  
Alphitonia excelsa ASH, SOAP   
Alstonia constricta BITTERBARK   

Aphananthe philippinensis  ELM, NATIVE  
Araucaria cunninghamii PINE, HOOP  
Arytera distylis COOGERA, TWIN LEAFED  
Arytera foveloata COOGERA, PITTED  
Atalaya salicifolia WHITEWOOD, BRUSH   

Atalaya salicifolia

Auranticarpa rhombifolia HOLLYWOOD, GOLDEN   
Backhousia angustfolia MYRTLE, CURRY   
Baloghia inophylla BLOODWOOD, BRUSH  
Brachychiton acerifolius FLAME TREE  
Brachychiton discolor  LACEBARK  
Brachychiton populneus KURRAJONG  
Brachychiton rupestris BOTTLE TREE  
Bridelia exaltata IRONBARK, BRUSH  
Bridelia leichhardtii IRONBARK, LEICHHARDTS  
Bursaria incana BURSARIA, FROSTY  
Capparis arborea CAPER TREE, RAINFOREST  
Capparis mitchellii CAPER TREE, MITCHELL'S  
Casearia multinervosa CASEARIA 
Castanospermum australe BEAN, BLACK   
Citronella moorei CHURNWOOD  
Citrus australis LIME, NATIVE ROUND   
Claoxylon australe BRITTLEWOOD    
Croton insularis CROTON, SILVER   
Cryptocarya bidwillii LAUREL, YELLOW
Cryptocarya glaucescens  JACKWOOD  
Cryptocarya triplinervis var. pubens LAUREL, HAIRY BROWN  
Cupaniopsis parvifolia TUCKEROO, SMALL LEAF   
Denhamia bilocularis (Maytenus bilocularis) ORANGEBARK, HEDGE   
Denhamia celastroides DENHAMIA, COMMON  
Denhamia disperma (was Maytenus disperma) BOXWOOD, ORANGE  
Denhamia pittosporoides DENHAMIA, VEINY   
Dinosperma erythrococcum TINGLETONGUE  
Diospyros australis EBONY, PLUM  

Diospyros humilis EBONY, SMALL LEAFED   

Diospyros humilis

Diploglottis cunninghamii (Diploglottis australe) TAMARIND, NATIVE   
Drypetes deplanchei TULIPWOOD, YELLOW 
Dysoxylum fraserianum ROSEWOOD  
Ehretia membranifolia KODA, THIN LEAFED  
Ehretia acuminata KODA  
Elaeocarpus obovatus QUANDONG, HARD    
Elaeodendron australe var. integrifolium 

              OLIVE PLUM, RED FRUITED  narrow-leafed
Elattostachys xylocarpa BEETROOT TREE, WHITE   
Emmenosperma alphitoniodes ASH, YELLOW   
Erythrina numerosa CORAL TREE, PINE MOUNTAIN   
Euroschinus falcatus RIBBONWOOD  
Everistia vaccinifolia EVERISTIA  
Excoecaria dallachyana POISON TREE, SCRUB  
Ficus rubiginosa FIG, SCRUB  
Flindersia collina ASH, LEOPARD   

Flindersia collina

Geijera parviflora WILGA  
Geijera salicifolia WILGA, SCRUB  
Guioa semiglauca GUIOA (Pronounced GHEE-OA)   
Linospadix monostachya WALKING STICK PALM  
Mallotus philippensis KAMALA, RED  
Melicope micrococca DOUGHWOOD, WHITE   
Myrsine variabilis (was Rapanea variabilis) MUTTONWOOD 
Neolitsea dealbata BOLLYGUM, GREY  
Notelaea microcarpa MOCK OLIVE, GORGE   
Owenia acidula APPLE, EMU  
Owenia venosa APPLE, ROSE   
Petalostigma pubescens QUIININE TREE, HAIRY  
Pittosporum angustifolium GUMBY GUMBY  
Pittosporum undulatum PITTOSPORUM, SWEET   
Planchonella cotinifolia (Pouteria cotinifolia) 

                                       CONDOO, SMALL LEAFED   
Psydrax buxifolium CANTHIUM, BOX-LEAFED  
Psydrax odoratum SWEET SUZIE 
Rhodosphaera rhodanthema YELLOWWOOD, DEEP   

 Rhodosphaera rhodanthema

Siphonodon australe IVORYWOOD  
Streblus pendulinus (Streblus brunonianus) WHALEBONE TREE 
Vitex lignum- vitae SATINWOOD

Some of our Local Dry Rainforest shrubs 

and Small Understorey Trees.

Alchornea ilicifolia DOVEWOOD, HOLLY
Alyxia ruscifolia CHAIN FRUIT 
Bursaria spinosa BURSARIA, SWEET  (Prickly. Good bird plant)
Carissa ovata KUNKERBERRY (Prickly. Good bird plant)  
Clerodendron floribundum LOLLY BUSH  
Clerodendron tomentosum LOLLY BUSH, HAIRY  
Denhamia silvestris (Maytenus silvestris) ORANGEBARK, NARROW LEAFED      

Dodonaea sinuolata HOPBUSH, THREADY-LEAFED  
Dodonaea stenophylla HOPBUSH, STRINGY LEAFED   
Dodonaea tenuifolia HOPBUSH, FERN-LEAFED  
Dodonaea triangularis HOPBUSH, TRIANGLE LEAFED  
Dodonaea triquetra HOPBUSH, FOREST   
Dodonaea viscosa subsp angustifolia HOPBUSH, NARROW LEAFED  
Homalanthus populifolius BLEEDING HEART  
Myoporum montanum BOOBIALLA, MOUNTAIN  
Notelaea linearis MOCK OLIVE, NARROW LEAFED  
Pittosporum revolutum PITTOSPORUM, YELLOW  
Pittosporum viscidum BIRDS NEST BUSH (Prickly. Good bird plant) 
Psychotria daphnoides PSYCHOTRIA, HEDGE  
Psychotria loniceroides PSYCHOTRIA, HAIRY            
Santalum lanceolatum SANDALWOOD, NORTHERN 
Santalum obtusifolium SANDALWOOD, SHRUB
Trema tomentosa PEACH, POISON 
Turraea pubescens WITCH HAZEL, NATIVE  

Thursday, October 6, 2016

Common Bulbine

Bulbine bulbosa

Spring is here, and our grasslands are full of the new season’s flowers, like this fragrant little bulbine lily. 

This plant can be expected to keep producing more flower-spikes like this one, through to late summer.


Each individual flower lasts only one day, but new flowers keep opening, up the spike, so each flower-spike is decorative for quite some time.

  Notice those lovely shaggy stamens!


 Despite its name, this perennial plant doesn’t actually have a bulb. It does, however, have a corm, with very fat, succulent roots attached to it.

The root at left is of a rather young plant, dug up in December. That little corm has a way to grow before it reashes full size. (Click on the photo for a closer look at it.) However the roots have already stored up a good supply of the starch which is to see the plant through winter.

 Bulbine bulbosa is “deciduous”, which means that its above-ground parts die down when flowering and seed production finish, and the plant then remains dormant until the following spring. The business-like root is the secret of its long life, letting it survive droughts, fire, and frosts.

Its leaves also work to help it make the best of the sparse rainfall of its natural habitat. They are channelled on the upper surface, a design which leads the rain into the centre of the plant, where it gives the roots more water than the surrounding soil.

The leaves are hollow, rather like slender onion leaves, and the plants have been called "wild onion". (Don’t eat those leaves, though. They are likely to give you a severe case of diarrhoea!)
The sweet, nutritious corms were one of the favourite summer foods of the Aborigines, and are said to be the best flavoured of the lily roots.  They fatten up throughout the growing season, and are best dug up at the end of the flowering season. They must be roasted, to make them safe to eat.
Like so many of our Australian plants, common bulbine is more popular in gardens overseas than here, which is a pity. For garden use, the best position for it would be in a garden of perennials where it can pop up again year after year.
It is a colony-forming plant in the wild, and a good colony can be quite spectacular. In gardens, the same effect can be achieved by planting bulbines in groups.
Despite their natural drought hardiness, they looks best if given some supplementary watering during the growing and flowering season.

Annual Bulbine
Bulbine alata
This is the taller of our two local bulbines. The flowers are very similar to the above, but the leaves  look as though they are coated with blue-grey powder.
It behaves as an annual in the wild, but well-cared-for, in a garden situation, it can be a clumping perennial. New plants can be grown from the tiny winged seeds, which should be stored for several months before planting. They are likely to take a month or two to germinate.
This species is found naturally in the Jondaryan area and further west, and is the best bulbine for heavy clay soil.

Monday, September 26, 2016

Volunteers Wanted, Thursday Mornings

Crows Nest Community Nursery
Depot Road, Crows Nest (35 minutes' drive from Toowoomba).

Crows nest Community Nursery is Toowoomba Regional Council's 
It specialises in growing the native plants of the Toowoomba Region. 
It opens from 9.00am to 1.00pm every Thursday.
Customers include those who buy in ones and twos for their gardens, and those who buy in thousands for large revegetation projects.
The plants include koala food plants, bird and butterfly-friendly plants, bush tucker, windbreak and honey tree species, and fire retardant plants for people who live in bush-fire-risk areas.

There are also plenty of our ornamental, but little-known, local native species, for the customers who just want something pretty.
 Velvet beauty berry, Callicarpa pedunculata
 Batwing Coral Tree, Erythrina numerosa
 Quinine bush, Petalostigma pachyphyllum

Staffing consists of one TRC-employed manager, and  a team of volunteers. 
There is no formal roster. Volunteers turn up as it suits them. The result is that there are usually between 6 and 10 volunteers on any given Thursday. 
Some are Crows Nest Residents, but most come out from Toowoomba, with some car-pooling to save petrol costs and to have company on the drive.
The nursery is becoming so popular that the volunteers have trouble keeping up with the work that could be done. So do consider joining the happy team!
Volunteers collect seed, store it in the seed bank, plant it, pot the seedlings on as they become ready, grow cuttings, tend the plants on the shelves, and generally do all the little tasks that keep the nursery running smoothly.

No experience needed. There are jobs for people with no prior knowledge of gardening and plants, and jobs for those with more expertise.
 All you need to do is to turn up at the nursery after 9.00am on a Thursday.
Alternatively, you could contact the manager, Lisa Churchward at TRC,
for more information. 
To find the Nursery:
Approaching Crows Nest from the south (i.e. from the Toowoomba direction), slow down at the 80 sign and take the first turn right into Industrial Avenue.
Follow the green street signs (which say NURSERY). 

Friday, September 9, 2016

King Orchids
Dendrobium speciosum var. hillii
(Thelychiton tarberi)

It’s king orchid time again, and these lovely plants are in flower in gardens, and in the wild.
Like all our native orchids, these are tough plants. You can see that this orchid is thriving in its very exposed situation, high on a tree in a degraded environment, where most of the original sheltering forest has disappeared.

It may have trouble making babies up there in its rather isolated site, though. First, it has to be found by pollinators, such as the stingless bee Tetragonula carbonaria. The chances are better when there are quite a lot of the orchids around top attract them, but it’s all a bit sad for the bees. Like most orchids, these lovely plants are “con artists”, attracting insects to do the hard work of transferring the pollen to other flowers, by promising nectar rewards with their shape, colour, and perfume – but not actually making the effort to produce any nectar. Working without pay is not fair in anyone’s book!
However, despite its fine show, this plant may be wasting its fragrance on the air. If no bee finds it, it will never produce seed, a continuing problem it shares with many of our native plants as our bushland is ever more segmented and it gets harder for the increasingly isolated plants to attract pollinators.

Unlike some of their closest relatives, king orchids are tree-dwelling plants. Their fine seeds are happy to germinate on the rough park of perfectly straight trees like the one below. All they need is for the right kind of fungus to be already there, to help the helpless little seeds to begin growing.

And orchid seeds are unusually helpless, which means they must become parasites from birth. Most parent plants provide their seeds with a little food package (endosperm) to feed the newly germinating baby plant. Orchids, in their enthusiasm for producing enormous numbers of their very tiny seeds, neglect this rather basic precaution. If none of their seeds can latch onto a suitable fungus nursemaid to provide them with the necessary nutrients, then the orchid’s efforts to create a new generation will fail.
Orchids are one of the most successful plant families in the world, proving that, all things being equal, it pays to be a user. All is not equal in our local environment, however, and our district’s once-rich orchid flora is dwindling away.
All praise to those who give it a chance to recover, by conserving and restoring patches of our local bushland.

Sunday, July 31, 2016

Forest Daisy

Brachyscome microcarpa
As usual in our fortunate part of the world, signs of spring appear almost as soon as the signs of autumn have gone.
Trees are bursting into new leaf, birds are looking around for mates, and little daisies are starting to open their bright eyes.

We have so many native daisies, that it can be difficult to identify them all. This one, however, is distinctive, with it’s unmistakable leaf shape, and its (relatively) large mauve flowers.

A plant of eucalypt woodland on light, well-drained soil (such as at the Bunya Mountains), it could make a useful, ankle-high ground-cover.
It prefers to grow in dappled shade, and where there is not too much competition from other plants.
It is commercially available (in several colour forms), but it may be difficult to buy plants of local provenance.
Once established, this is a plant that would need little care, resisting both drought and light frost.