Saturday, April 25, 2015

Box Leafed Canthium

Psydrax odorata forma buxifolia
FAMILY: RUBIACEAE
This small tree species had one of its magnificent flowering years, all around the district, this year.

 
Having delighted us with its lovely fragrant flowers, as well as delighted the insects (and the birds which feasted on them), it is now ripening fruit. There will be a second feast for the birds, shortly.
 
This is a plant that is rather slow-growing, but very pretty from infancy, with its geometrically neat, paired branches.
 
Here is a pretty specimen in Peacehaven Botanic Park at Highfields.

Its small rounded shiny leaves have a (very) vague resemblance to the English box which is the reason for it’s common name. (Won't it be nice when English-speaking Australian culture has matured to the point where our plant names reflect a love for our native plants for their own sakes, rather than always having to compare them with something from the "old country"?)
Some people call it “native jade”, because it can fill the “jade niche” in gardens for those who would rather grow a local native plant. I find it much prettier than jade. Here it is as a pot plant on my patio.
 
Like so many local dry rainforest plants, it is very long lived, so makes a good pot specimen for many years.
It prefers a sunny position, and is drought and frost hardy.

Tuesday, April 14, 2015

BOWER VINE

Pandorea jasminoides
I was amused to hear a backhanded compliment given to this plant, a few years ago. “It doesn’t look like a native!” the speaker said, in a tone which implied that she believed she was bestowing high praise.

Bower vine has become such a familiar sight in our mainstream gardens, that it can be a surprise to discover that not only is it native to Australia, but it is a local plant, growing in the scrubs in the Toowoomba area and along the Great Dividing Range.

These flowers were picked up off the ground in Franke Scrub, Highfields.
As the name “bower vine” suggests, these plants are substantial vines with woody stems, suitable for training over an arch or pergola to make a lovely shady bower. (I suggest planting up to four plants for a quick shade cover.)They are also popular on fences and trellises.

Alternatively, they can be used as a dense, bird-sheltering groundcover, in an open situation where they won’t find anything to climb on. (Let them find a shrub or tree, though, and they’ll take to the heights.)

The pandorea species are named for Pandora, the poor woman who, according to ancient Greek legend, is "responsible" for all the world’s troubles. She was set up, of course. Zeus (a male god, please take note) gave her a box as a wedding present, with the clearly stated aim of tricking humans into accepting an "evil gift".  When she opened it, all unaware of its contents, out they spilled like seeds from the pods of the Pandorea vines. In the myth, these contents were all the troubles of the world, but with Pandorea vines, they are just seeds. They are easy to grow, so if you get hold of one of the pods that are ripening on the vines at this time of year, you can have as many of these lovely vines as you could want.

Bower vines are hardy to Toowoomba droughts, especially if mulched. As with most climbers, their favourite site is one where their roots are in the shade but the canopy is in full sun, where it flowers best.
In a bushfire, these plants are a little more resistant to catching fire than some, which makes them a good plant for fencelines where fires are a concern. No plant is fireproof, though. However, bower vines can be among the first to regrow from their roots once the fire has gone.
They are frost tender when young.








Friday, April 3, 2015

Tree Ferns

The local treeferns will be loving all this rain!
These lovely, lacy fern-umbrellas are wonderful in a shady garden, and some will tolerate a considerable amount of sunlight. It’s a matter of choosing the right species.
We have two local treefern genera – Cyathea and Dicksonia. Of the two, Cyatheas tend to be hardier in our part of the world, and are therefore popular in cultivation.
Unlike Dicksonia antarctica, whose trunk is  covered with soft red-brown hair, the Cyatheas have scales. This surprises me, as what are apparently long narrow scales look like coarse hairs, to me. However, they contrast with the soft hair of the Dicksonia, which is rather nice to touch.

Rough Tree Fern
Cyathea australis
Family: CYATHEACEAE


This may be the best treefern for local gardens. It is hardiest local tree-fern, the most widespread in nature (in our district) and the most commonly grown in gardens. It is the best for tolerating sunshine, drought and (light) frost, and can even regenerate after fires.
It was probably once quite common in the Toowoomba area, in the shady forests on both sides of the range. While tree ferns are usually thought of as rainforest plants, this one also grows in the wetter Eucalypt forests.
It is a tall, stout and sturdy plant. Its "roughness" comes from the blunt prickles on the leftover frond bases which clothe the trunk. Its red-brown scales distinguish it from our other local Cyathea species which has straw-coloured scales.

It can be rather slow-growing, but watering, and mulching to keep the soil moisture level reasonably high helps it grow faster.


Coin-spot Tree Fern
Cyathea cooperi  
Family: CYATHEACEAE

This species may also have once been common in Toowoomba. A few naturally occurring plants still exist in a stream on the south-west side of Mt Kynoch, which flows into Gowrie Creek. It is considered to be a plant of wet rainforests, so these rather surprising survivors, now growing in a closed forest consisting mostly of privet, probably indicate that Gowrie creek itself used to flow through lush rainforest.

Almost as hardy as Cyathea australis, it differs in having a slender trunk, whose the leaf bases usually (but not always) fall off, leaving large, smooth oval spots which give it its common name.
 
The bases of the leaves have a distinctive curve, which give the plant a crown unlike any other local species.

Though it is happy with its head in the sun, it prefers a cool, shady, well-mulched root-run, with as much water as the garden-owner can afford to give it.Given these conditions, it is our fastest-growing treefern species.



Soft Tree Fern
Dicksonia antarctica  
Family: DICKSONIACEAE

This is our thirstiest local tree fern. In our district, we find it only in the damper rainforests on the edge of the Great Dividing Range.
It can be distinguished from our other treeferns, the Cyathea species, by the softness of its red-brown hairs.
 
It reminds me of an orangutan, but Tasmanians know it as a  "man fern", apparently because the thick trunk is so often about the size and proportions of a man. While there are plenty of upright specimens, the plant often leans, or simply lies down.


The hairy trunk provides niches for lots of little epiphytes, especially little ferns. This could be used to great advantage in a damp garden. Unlike the Cyatheas, this plant absorbs water through its trunk, so it is often grown with help from automatic sprinklers.
In the wild, it has suffered from the fact that it can be transplanted simply by cutting off the trunk at ground level, planting it in its new site, and watering it well. The temptation to plunder nature for a plant which is worth quite a lot of money is too difficult for some people to resist. Unfortunately, in the Australian climate, with its regular droughts and water restrictions, it has proven too easy to kill before it has become properly established.
While it is a lovely plant, its water needs mean that gardeners might feel that one of the Cyathea species is a more environmentally friendly choice.

All three of our local tree fern species grow in the Bunya Mountains, and all of them can be seen at different points beside the short walking track from the Dandabah car park to the Festoon Falls.





Tuesday, March 24, 2015

Orange Boxwood


Denhamia disperma (Maytenus disperma)
Family: CELASTRACEAE
This little local dry rainforest tree is fruiting in Franke Scrub at present. 
 
It’s yellow-orange seed capsules usually have one or two of the nut-brown seeds, but here’s an unusual one with three.

A neat little tree, with a dense canopy of shiny brown leaves, this would be an ideal small shade tree for a suburban garden. It is unlikely to exceed 6m high, in a garden situation.
The photo below, of a four year old tree, shows how it has a dense canopy from an early age.
 

Like most of our local dry rainforest trees, it is fast-growing if given mulch and water in it’s first year or two of life.
It’s a good bird- attracting tree. The dense leaves provide shelter and nesting sites, the flowers attract insects at breeding time, and the seeds provide an annual food crop.

Tuesday, February 17, 2015

What’s Happening to my Native Bee Hive?

We are very fond of our hive. It was given to us after its discovery in a felled tree, and we made this nice little position for it, facing north-east and sheltered from most of the heat of the summer sun. In winter, the different sun angle plus a bit pruning of the native jasmine (Jasminum didymum subs. racemosum) overhead makes sure it is sun-warmed.



The bees are stingless native honeybees, Tetragonula carbonaria (Trigona carbonaria).
Their hive has thrived, and each day a stream of busy little workers heads back to the hive, with healthy corbicular loads of pollen on their back legs. Although we hadn’t noticed it, some would also have been carrying resin, which they use to make their comb.

Its door usually looks like this:

(The pairs of yellow dots are the rear ends of bees scurrying into the hive laden with pollen, their little black bottoms invisible in the photo.)

Then a few days ago we noticed it looked like this:


Alas, what has happened is that my little native bees have found a cadarghi tree, Corymbia torreliana (Eucalyptus torelliana), whose sticky seeds have been abandoned all around the mouth of the hive.
Cadarghi is a north Queensland gumtree which doesn’t grow naturally south of Ingham. It was widely introduced into southern Queensland as a fast-growing shady garden plant, and has thrived, becoming an environmental weed which damages local ecosystems.
It is interesting botanically, because it has been discovered that native bees disperse its seeds, and this is the first known example of bees as dispersal agents.
The bees don't mean to bring the seeds home. They only want the resin out of the gumnuts, and (no doubt to their annoyance) the seeds stick on to their load of resin. Getting rid of them after cleaning, they are likely to disperse the seeds within 10m of my hive. Here is one of my little bees, carrying out a C. torreliana seed which has accidentally been brought into the hive.



Every 10 seconds or so in the working day, another bee brings out another seed, so hundreds of seeds are being dropped around my garden. Frankly, I could do without this! I already weed out privet, lantana, camphor laurel, jacaranda, Chinese celtis and lantana. Another environmental weed tree is something I do not need.

The bees try to leave their seeds outside before entering their home which is why some seeds are clustered around the door. This bee in the photo below seemed to have almost succeeded. The seed hung by a little sticky thread from the resin on its back leg. It gave up the attempt, and limped into the hive with the seed still attached.



The bees will probably not manage to clean out all the seeds in their hive. What they leave behind may clog passageways and prevent ventilation and free movement of bees.  I have since scraped away the external seeds, which you can see (Photo 3) were beginning to block the doorway, reducing the flow of the air to interior. But I can do nothing about the seeds inside.

Meanwhile there is a risk that the C. torreliana resin which they are now using for interior construction, will start to melt on a hot day. (It has a lower melting point than the other resins they have been using.) We can just hope that the hive’s shaded position and its insulated container will keep it safe from internal collapse.

These native bees are essential pollinators of large numbers of native plant species, and are the only pollinators of some of them. There is a risk that the spread of this harmful tree species, and the resulting damage to the population of our local pollinators, will interfere with the fertilisation of seed of who know which species of native plants. Pollination of Australian plant species is still only very partially studied, so there is much still unknown about how many plants are pollinated. In the fragmented modern remnants of our ecosystems, people are noticing that some healthy trees don't seem to be producing a new generation of seedlings. Perhaps our unwitting damage to populations of pollinators is part of the problem.

........................................................................................


To quote from a Biosecurity Queensland website on Weeds of Australia:
“Cadaghi (Corymbia torelliana) is regarded as an environmental weed in south-eastern Queensland and as a potential environmental weed in New South Wales. It is becoming a serious weed in Queensland, where native bees collect its resin-coated seeds and spread it into eucalypt forests all over south-eastern Queensland.
This species has a very dense canopy of large leaves that is well suited to the rainforests of northern Queensland. When growing in open woodlands, outside its native range, it creates a heavy shade over the native understorey plants and prevents them from growing. It therefore has a significant potential to modify the diversity and structure of the native forests in sub-tropical Australia....
... The sticky resin from the fruiting capsules is collected by native stingless bees (e.g. Trigona carbonaria) and can completely clog the honeycombs and sometimes also seal the bee hive entrance, killing all the bees inside. This tree  often gets covered in a sooty fungus, which can dirty or discolour things that are underneath it (e.g. vehicles, pavers and outdoor furniture). The large horizontal limbs are also prone to snapping off and damaging property.”

(http://keyserver.lucidcentral.org/weeds/data/03030800-0b07-490a-8d04-0605030c0f01/media/Html/Corymbia_torelliana.htm )

A 2013 study on Australian stingless bees by Megan Halcroft, Robert Spooner-\Hart, and Anne Dollin  adds this information:
“Corymbia torelliana seeds are mainly dispersed by gravity; 88% of seeds drop to the ground soon after the fruit opens. However, one or two seeds remain within the gum nut and all are dispersed by Trigona. Resin is produced in the gum nut... When the bee enters the nut to collect resin, the seeds attach to the sticky corbicular load. Seeds are dispersed by bee(s)...and may be spread during the flight back to the nest or transported to the nest itself. This may be up to 1 km away from the tree...
... Trigona are strongly attracted to the resin from C. torelliana and the colonies stop normal foraging activity to collect as much of this resource as possible. As foragers return to the nest some attempt to dislodge seeds on the nest exterior, while others transport seeds directly into the nest cavity. The colony removes some, but not all, of the introduced seeds and these are either disposed of, up to 10m outside the nest or adhere to the sticky surface of the nest entrance... reducing airflow within the nest...
... Resin from C. torelliana may have a lower melting point than many other plant resins. Collection of the resin and its seed occurs during the hottest months of the year in Australia — December to February... and as temperatures rise, the resin begins to soften. Reports of structural collapse due to seed weight and resin softening are not uncommon, particularly if ambient temperatures exceed 39°C. As a result, some beekeepers remove their hives from C. torelliana areas during resin flow to prevent colonies from collecting the resin and seed mixture. While many Australian beekeepers consider C. torelliana to be a major management problem, others consider it to be a useful source of pollen, nectar and resin.”

The site also remarks:
“Not declared or considered noxious by any state government authorities.”

 http://www.beesbusiness.com.au/articles/Halcroft%20et%20al_ch3%20pot%20honey.pdf
 

Tuesday, February 10, 2015

Rainforest Plant ID Workshop


Presenters: Gwen Harden and Bill McDonald


Sunday 22nd February 
commencing at 8.30 am for a 9 am start

WHERE: 210 West Street, South Toowoomba (between South and Alderley Streets)
Parking in Derwak Street off West Street

COST: $5.00 per person. Morning Tea included

REGISTER: Hugh Krenske hkrenske@210west.org.au, or Ph 4635 1758, or 0418 748 282.
Places are limited, so it’s best to book soon.

LEARN: to identify plants of Rainforests and our local Dry Scrubs, using the new interactive USB key for computers, “Rainforest Plants of Australia” by Gwen Harden, Hugh Nicholson, Bill McDonald, Nan Nicholson, Terry Tame and John Williams
For more information on the key, see http://rainforests.net.au

This new USB key makes it easy for amateur plant enthusiasts, and people new to botany or unfamiliar with our local plants, to identify the natives of our rainforests, scrubs, and vine thickets.
Of the 1139 plants in the key, about a quarter are native to the eastern Darling Downs, so the key is of immediate practical use in our local area. It can give us the ability to identify many of the plants we find on our roadsides and our properties, and in our National Parks and Conservation Reserves.
It comes with good descriptions of all the plants, line drawings, and an average of over 10 brilliant photos for every plant species.
 

BRING: 
1. Your key if you have one (You can purchase one at the workshop for $70)
2. Your laptop if you have one. Please check that your laptop has the necessary system
requirements to run the key at http://rainforests.net.au. RUNS ON WINDOWS AND MACS.

SPECIAL OFFER: Gwen will have copies of the key available at the workshop for $70.00.
She will also have for sale copies of the famous “red book” and “green book” - “Rainforest Trees and Shrubs” and “Rainforest Climbing Plants”, by Gwen Harden, Bill McDonald, and John Williams. There will be an opportunity during the morning for those who want to learn “keying out” plants from these books, rather than from the computer key.

OPTIONAL:
1. Share a BYO lunch.
2. Early afternoon Rainforest Walk and Talk with Bill and Gwen in the rainforest secton of the Boyce Garden (corner Mackenzie and Range Streets). This is one of the last remnants of rainforest
within the Toowoomba city limits.

This workshop is hosted jointly by Toowoomba Field Naturalist Club and Friends of the Escarpment Parks Toowoomba Inc. 

Saturday, February 7, 2015

Warrior bush

Apophyllum anomalum
Family: CAPPARACEAE
Female warrior bushes in Irongate conservation reserve are laden with fruit at the moment.



They are obviously very attractive to birds, as many of these fruits have been “robbed”, the seeds  taken and the skins left on the bush.



People can eat the fruit, too, should they want to, which is the reason this plant is sometimes known as “native currant”. (As there are some half a dozen other Australian plants also called native currants, and as the fruit isn’t really much like a currant at all, this is not a particularly useful common name!) They are sweet tasting, so won't give you a nasty shock if you put them in your mouth, but they are hardly worth the trouble. There is very little flesh between the inedible skin and the fruit.



Warrior bushes have tangled, somewhat spiny branches. Young plants have small, narrow leaves, but as they mature they lose them and the job of photosynthesis is done by the green branches alone.

  

The tiny spines make them a little unfriendly, though the branches tend to form a tight canopy which doesn’t put itself in the way of passers by. Birds like to nest in their protection.

Warrior bushes are in the same family as our native caper plants, and like them they host the various species of caper butterflies, which can be seen in great numbers almost all year round at Irongate.

Livestock also eat the branches, undeterred by the spines. The result is often a neat, well shaped bush. In sheep country they develop a clean-stemmed lollipop look, which teaches us how well the plants respond to pruning.

  

Old trees have wonderful trunks. This magnificent specimen at Gowrie Junction could well be several hundred years old.

This would be a very good plant for a formal garden, but don't expect quick results from a seedling. Warrior bushes would be best placed in between other shrubs, to mature and grow in their own time.
They are frost hardy, and tolerate extreme drought.