Saturday, October 2, 2021

 

 “Yellowtop” or “Fireweed”?

Which yellow daisy is which?


Senecio brigalowensis, BRIGALOW YELLOWTOP (Native, annual)
Senecio pinnatifolius var. pinnatifolius PERENNIAL YELLOWTOP (Native, biennial or perennial)
Senecio madagascariensis*, Madagascar fireweed (Non-native, annual or biennial, a serious weed)


The countryside around Toowoomba is ablaze with yellow daisies at the moment. There are three species involved, but from a distance, the plants seem almost identical.
To some people, they are all “fireweeds” and are treated as equally undesirable.
Two of the three species are native, however, and are important hosts for some beautiful and  increasingly rare native insects.  (See http://toowoombaplants2008.blogspot.com/2017/06/mountain-katydid.html or search for Mountain Katydid, Acripeza reticulata).
So which yellow daisy is which?
It is quite easy to distinguish Madagascar fireweed from the other two species by the shape of its leaves. All Senecios have leaves of a rather variable size and shape, but if you are trying to tell one yellowtop/fireweed from the others, look for the leaves around the middle of a fully-grown plant. They will still be variable, but you can get a good idea of the most common leaf shape.
The leaves of Madagascar fireweed (Senecio madagascariensis*), are spear-head shaped, with teeth, as below:

 

The leaves of both the native species have long thin lobes, which gives them a “whiskery” look. The one shown below is Senecio brigalowensis.



The leaves and leaf-lobes of Perennial yellowtop (Senecio pinnatifolius var. pinnatifolius) tend to be narrower than those of Brigalow yellowtop (Senecio brigalowensis), but there is some overlap so this is not a reliable guide. If the “whiskers” of the leaves have any very tiny teeth on the edges, you have Brigalow yellowtop, but many brigalow yellowtops have no teeth - just the long, thin, thready-looking lobes as above.
The most reliable way of distinguishing between the two natives is to count the bracts (not the petals). The bracts are the tiny green strips which make up the green cup in which the daisy flowerhead sits. You may need a good pair of reading glasses to count them, and at first though this seems like a hopeless task. 

 

However brigalow yellowtop (Senecio brigalowensis) has more than 18 bracts and in practice there are usually about 22 of them. Our local (Darling Downs) perennial yellowtops (Senecio pinnatifolius var. pinnatifolius) have only about 13. Really, by the time you are half-way round you are going to know whether the full count is going to be more like 13 or 22, so it’s not that hard after all. Can you see, by the photo above, that you are looking at perennial yellowtop? Enlarge the photo and you can see only 6 or so bracts on this side. There is not going to be room for a total of 22 altogether, so you hardly need to count them all the way round! The bracts of the perennial yellowtop also tend to be purple-tipped, but this is not always a reliable indicator.

Perennial yellowtops flower later than brigalow yellowtops, and don't tend to produce such a crowd of plants. Their petals are also somewhat longer and slimmer. Once you know both plants you will find you can distinguish them at a glance.


MADAGASCAR FIREWEED Senecio madagascariensis*
Poisonous to horses, cattle, pigs and poultry.


If you have this one, you should get rid of it as soon as you can. It can have SIX GENERATIONS of seed per season. (Native yellowtops breed at a more civilised rate, only producing one generation of seed per season.) You can see why a few Madagascar fireweed plants might turn into a rather big problem rather quickly.
To make it worse, if you pull out plants with flowers but no seed on them, any flowers can mature and produce viable seed while they are drying out in your garbage bin. The seeds have fluffy tops designed to blow in the wind, so those plants that you thought were safely disposed of will spill seed even as your friendly helpful garbo is tipping your rubbish into the truck. The moral of the story is that all Madagascar fireweed flowers, as well as seeds, should be carefully placed into a sealed plastic bag for disposal.


BRIGALOW FIREWEED Senecio brigalowensis
Poisonous to horses, cattle, pigs and poultry.
Every few years in spring we have a big flush of these flowers, and this year is a biggie. Our paddocks and some road verges are sheets of yellow. They do like disturbed land. If you want to see a really good display, drive around the northern edge of Toowoomba on the new bypass road. You will notice how the road verges are a mass of colour, but very few plants have spread to the other side of the fence. The same can happen between one paddock and the next, which tells you some things about those paddocks’ different histories or use patterns. Heavily grazed paddocks are more prone to a big flush of yellowtops.
The curious thing is that it is only in some years that we have these big flushes, and it has only been happening here since 2007. Nobody is sure why, but it probably has something to do with our changing climate.
Unless you (or you neighbours) have horses or cattle, these lovely wildflowers can be left alone for you to enjoy, and for small native creatures to feed upon. They are part of our natural Australian environment.
Don’t feed them to the chooks, though.


PERENNIAL FIREWEED (Senecio pinnatifolius var. pinnatifolius Syn Senecio lautus ssp. dissectifolius)
Not regarded as dangerous to livestock.
This plant flowers a little later in the season, and never reaches pest proportions. You will notice it scattered about in paddocks which are grazed by cattle, with no resulting problems. In a well-managed (not overgrazed) paddock, such as the one in the photo below, they are not a problem. Perhaps they taste nasty, so cattle avoid them unless they are in a situation such as a stockyard or stock route, where heavy grazing leaves them with little choice of fodder.

They are a local wildflower to celebrate. What a pity that the issue of whether or not to let them grow is so confused by their weedy relatives.







Friday, September 17, 2021

Which Greenwattle is Which?

Acacia decurrens
SYDNEY GREEN WATTLE
Acacia irrorata
CINNAMON GREENWATTLE

Family: MIMOSACEAE

Photo: Max Henderson. Acacia decurrens.

I have walked past these plants in Duggan and Hancock Parks (Toowoomba) many times, and simply failed to notice that they are not the ordinary local greenwattle, Acacia irrorata, which is a very similar plant.

Photo: Max Henderson. Acacia decurrens.

 
I wasn’t certain whether to be disappointed or delighted. Really, they are an environmental weed. However they are also a part of Toowoomba’s history - a reminder of a lost industry.
Native to the area around Sydney, their value as a source of tanbark was recognised early in our colonial history, and bark-strippers began plundering the naturally-growing plants. To ensure an ongoing supply, Sydney greenwattle plantations were established up and down Eastern Australia, to produce bark for tanning leather. They were also introduced to southern Africa and California. They have naturalised, and are spreading in many of these habitats, where they are now an environmental weed. Around Toowoomba, however, they are not aggressive colonisers, so are not an weed of any serious importance.
Whether they produced better bark for tanning than our local green wattles is doubtful. As we so often see, a certain plant becomes popular,often because it is simply better known, because its natural habitat is near a major cit. Then it planted in other areas regardless of whether there is a better local plant available. The people establishing the Toowoomba plantations would have found the seed of the Sydney greenwattle easy to obtain, and might not have even investigated the qualities of the bark of the local species, let alone wanted to pay staff to collect its seed. Here, they would have been used in our once-thriving and prosperous tanneries.

Our local Acacia irrorata is a plant with a wider natural range extending from Gympie to Gippsland. Down south, they call it “blueskin”. I have no idea why. Perhaps a southern reader will enlighten me? It is also called Cinnamon Greenwattle, because of the cinnamon scent of its leaves - a scent which is absent in A. decurrens.

As new seedlings, both species look remarkable similar. However, distinguishing the two is quite easy, even from a distance, once they have reached a metre or more tall. Acacia decurrens has a shiny, bright green look about it, while Acacia irrorata has softer-looking, non-shiny, dull green leaves. There is also a slight difference in the colour of the flowers, with A. decurrens having more strongly yellow flowers, while those of A. irrorata are a more creamy yellow.

Photo: Acacia irrorata

Acacia decurrens has a noticeable gland on the leaf-stem (petiole). Both of them have glands further along, between the leaflets, but A. irrorata has no gland on the petiole.

Photo: Max Henderson. Acacia decurrens.

 The fresh yellow growth tips also differ. Those of A. A. decurrens are usually hairless, while A. irrorata has growth tips that are softly hairy to the touch.

The tiny leaflets of A. irrorata are no longer than 5mm long. In A. decurrens they are always longer then 5mm, and can be as much as 15mm.

Which One to Grow?
Local people choosing to grow a plant species for environmental reasons should choose Acacia irrorata because it occurs naturally in the Toowoomba district. It has always been very common locally. (It is the plant that Greenwattle Street is named for.) It is a fast-growing plant with a life-span of not much more than 15 years, which makes it an excellent choice for beginning the task of restoring a wildlife habitat where the land has been cleared of trees. It is also a great plant for creating a fast windbreak, where several rows of trees are to be planted. One row could be of this species, which will be up and doing the job while the more long-lived species are getting their act together.
It attracts a very wide variety of insects, so brings in birds and other insect-eating wildlife species.



Photo: Acacia irrorata

Thursday, August 26, 2021

Gargaloo - something to add

 Parsonsia eucalyptophylla 

 




I love it when a reader tells me something I didn't know.

 Jane Pye of Walgett read my original blog about this pretty, drought-hardy vine, and wrote to ask me about its tuber. Could I could confirm that it was poisonous? She added "There is a lot of it here around the old kamilaroi camps so seems odd they encouraged a poisonous vine - why not the bush banana instead? "

 Having had no idea that it even had a tuber, I was no help to her. I have never thought to dig up the roots of one and examine them. I couldn't find any botanical descriptions which mention a tuber, so perhaps no botanist has ever dug one up, either. I did find a reference that said that cattle and sheep "eat it" apparently without ill effect. Sheep are known to dig up some tubers, but perhaps this comment refers only to the above-ground parts of the plant. Could the gargaloo tubers be too deep for the sheep to find? Or perhaps the first nibble tells them that it tastes bad, so it gets left alone. 

Presumably a gargaloo which has been eaten to the ground can then regrow from the tuber.

My original blog about the Gargaloo can be found at https://toowoombaplants2008.blogspot.com/search?q=gargaloo

An article about the  poisonous tuber can be found here: https://archive.lls.nsw.gov.au/__data/assets/pdf_file/0011/495749/archive-vines.pdf 

Jane has an excellent blogsite of her own, which I recommend to you. You can find it at https://scartrees.com.au/

 

A gargaloo seed capsule (below).  The ripe seeds have little silky "parachutes" which help spread the seeds. Just a few of these seeds may have been lucky enough to land in a suitable spot to create a new plant.

  Gargaloo flowers have a lovely honey scent. The plants west of Toowoomba seem to me to have a more appealing fragrance than those on plants further east. They appeal strongly to butterflies.

 And finally, a photo which shows the distinctive flower shape of Parsonsia flowers - but will also appeal to the readers of a certain very popular children's book by Richard Scarry. 

 Here's Goldbug!  

(Double click on the photo to enlarge it, and you will see him.)

Friday, December 4, 2020

Python Tree

Gossia bidwillii. 

 
Australia specialises in trees with beautiful trunks. This is one of our loveliest.



 

It is a small tree. For the most part it is found in vine scrubs and dry rainforests along the range, but also occurs in the remnants of the Gowrie Scrub, a once-large scrub which stretched from Highfields and North Toowoomba through Gowrie Junction to Kingsthorpe and beyond. It is very suitable for suburban gardens.


Its name comes from the smooth mottled python-like trunk, which is cool to the touch even on a hot day. (Some people call it “refrigerator tree”. ) Its shape often suggests muscles under the skin. The specimen below, which has obviously had a hard early life, shows these “muscles” to an exaggerated extent.



 

The distinctive upper roots at the base of the trunk are often exposed, and are a feature which helps you identify the tree in the wild.



 

The shiny green leaves resemble lillypilly leaves, except that they have red-brown twigs, which help you to to distinguish them.



 

They are a brilliant, translucent red when new, and make a great show in the garden.


 
Python trees have juicy, edible fruits. 



 

If you pick one in the wild to try, don’t forget to plant the seed in a suitable spot after you have sucked it clean. This species is in decline, and would appreciate the little bit of help to produce the next generation.

Sunday, May 31, 2020

Talking about Leaves

Botanical jargon can seem off-putting to a beginner, but it is worth the trouble of learning a bit of it. Knowing some of the botanical words makes aware of what details about leaves to look for, and the more we know about what to look for, the more details we notice.

So let’s start with a few easy botanical terms, and what they mean.

Alternate or opposite leaves?
If you’re looking at a plant and wondering what it is, this is one of the first identifying features to look for.

Opposite simply means that the leaves are in pairs. Here is a specimen of a local climber with opposite leaves.


Stiff Jasmine, Jasminum simplicifolium - for more details on this plant see: https://toowoombaplants2008.blogspot.com/search?q=pearls

Alternate means the leaves are joined onto the twig (botanical term: branchlet) one at a time, not in pairs. The plant below has alternate leaves along its slightly zig-zagged branchlets.


Scrub Wilga, Geijera salicifolia - for more details on this plant see:
https://toowoombaplants2008.blogspot.com/search?q=bone-chilling.


Simple or Compound Leaves?

This is a little trickier. A simple leaf is never divided into leaflets. Simple leaves come in a lot of different shapes, but there is always is just a single leaf-blade, joined directly to the branchlet. The Jasmine and the Wilga above have simple leaves.
So does the plant below - and you will notice that they are opposite.


Red Olive-plum Elaeodendron australe var. integrifolium, - for more details on this plant see:
https://toowoombaplants2008.blogspot.com/search?q=olive-plum


Another local with simple, opposite leaves is this one.


Small Fruited Mock Olive, Notelaea microcarpa - for more details on this plant see:
https://toowoombaplants2008.blogspot.com/search?q=Rosenthal


This one has simple, alternate leaves:


Scrub Boonaree, Alectryon diversifolius - for more details on this plant see:
https://toowoombaplants2008.blogspot.com/search?q=dormitory


And here’s another one which also has simple, alternate leaves:

Breynia, Breynia oblongifolia.

Instead of being simple, leaves can be compound.
This means that the leaf is divided up into sub-leaves (botanical term: leaflets). This cam be confusing, because leaflets look rather like leaves!

The picture below shows ONLY THREE leaves. They are the kind called compound leaves, rather than simple leaves.


White Beetroot Tree Elattostachys xylocarpa - for more details on this plant see: 
https://toowoombaplants2008.blogspot.com/search?q=multiple-trunked

Two of its leaves are divided into five leaflets each, and the other leaf has only two leaflets.
You could mistake those leaflets for simple leaves, couldn’t you?



 White Beetroot Tree Elattostachys xylocarpa

The difference can be seen by looking at the join between the leaf-stalk and the branchlet. (The botanical term for this join is “axil”.) Can you see that there is a shoot coming from the axil? Only leaves have those shoots. There is never a shoot at the base of leaflets. The position of the shoot tells you that you are looking at compound leaves.
  
(And did you notice that this plant has alternate leaves?)

So does this one below - and its compound leaves are very large.

Deep Yellowwood, Rhodosphaera rhodanthema, - for more details on this plant see: https://toowoombaplants2008.blogspot.com/search?q=deep+yellowwood
 
Note the tiny shoot in the leaf axil, by my finger. The shoots in leaf axils are sometimes just very small points, so you need to look carefully for evidence that this is a compound leaf.

Also note the white sap oozing from the places where I have snipped off leaves, so I could show a clear photo of a single leaf. Relatively few trees have white sap, so this is an important identifying feature. (I washed my hands afterwards, an important precaution after handling this kind of plant.)

White beetroot tree and Deep Yellowood have the kind of compound leaves called pinnate leaves. Pinnate is a word about feathers. Can you see how the leaves in the photo above are arranged a bit like a feather - with a leaflets lined up on either side of the central rib, like the barbs of a feather? The central rib of the leaf is called the rachis. (Pronounced RAH-KIS) The strong central spine of a feather is a rachis, too.

Trifoliate Leaves

Here is another plant with compound leaves. In this case, its leaves are opposite.




Triple Leaf Jasmine, Jasminum didymum subsp. racemosum - for more details on this plant see:
https://toowoombaplants2008.blogspot.com/search?q=didymum

 
Despite its deceptive common name, it is the leaflets that are triple, not the leaves. If you look closely (double click on the photo) you can see the beginnings of shoots in the leaf axils.

Plants with compound leaves, having three leaflets arranged in this pattern are called “trifoliate” (or some people prefer “trifoliolate”, which is such a tongue twister that the word is dropping out of use, despite its being more correct). So the jasmine above has opposite, trifoliate leaves.

Here is another example of compound leaves which are trifoliate.

Tingletongue, Dinosperma erythrococcum. 
 
Can you see that there is a tiny shoot at the base of those trifoliate leaves? And that the leaves are opposite?

Now for a plant family - one with spikes.
A word that helps you identify quite a few of the trees in our local scrubs and dry rainforests is Sapindaceae, (Usually pronounced SAP-IN-DAY-SEE)
It is the name of a plant family, and we have an unusually large number of its members here in our local area. They all have alternate leaves. A few, (like the Scrub Boonaree) have simple leaves, but most of our local Sapindaceae have pinnately compound leaves.
Members of this family can be picked out from other plants with pinnate leaves by a small spike at the tip of the rachis, just where the top leaflet-stem joins on.


Scrub Boonaree, Cupaniopsis parvifolia. FAMILY: Sapindaceae

 You will also find spikes on the rachis-tips of a plant we looked at, earlier in this blog.


White Beetroot Tree Elattostachys xylocarpa.  FAMILY: Sapindaceae

We’d better have a closer look


 White Beetroot Tree, Elattostachys xylocarpa. FAMILY: Sapindaceae

And here's another member of the Sapindaceae family.



Pitted Coogera, Arytera foveolata. FAMILY: Sapindaceae
 
The spikes at the tip of the rachis, of its pinnately compound, alternate leaves, are rather blunt.
 
 
Pitted Coogera, Arytera foveolata. FAMILY: Sapindaceae


Looking at the back of the Beetroot Tree's leaflets, you can notice another interesting feature.


White Beetroot Tree, Elattostachys xylocarpa.

There are little hairy pits, at each junction of a side vein with the main central vein,. These pits are called domatia. The word means “little homes”, and that’s exactly what domatia are.


White Beetroot Tree, Elattostachys xylocarpa.
 
Domatia are good investments for the trees that have them. They have evolved these structures so they can be landlords. Small mites move in, and “pay their rent” by preying on small insects which would otherwise eat the leaves.

Some species of plants have them, and some don't. Where domatia are present, they give another clue to the identity of the plant.

These leaves also have domatia.
Pitted Coogera, Arytera foveolata

You could easily overlook them, couldn't you? If you double-click on the photo they will be easier to see, and now that you know the word, domatium, perhaps you will look with more interest at the backs of leaves and leaflets.

And I hope that you will be more aware of whether leaves are alternate or opposite, and whether they are simple or compound. If they are compound, you can look to see whether they are trifoliate or pinnate. If they are pinnate you can check  whether they are members of the Sapindaceae family.

What else can you learn about leaves?






Thursday, January 2, 2020

TRIPLE-LEAF JASMINE
Jasminum didymum subsp. racemosum
FAMILY: OLEACEAE







This common local plant is one of our four local species of jasmine. A mature plant produces large numbers of tiny, fragrant white flowers in summer, and is a favourite feeding spot for insects including various species of native bee.  The dense foliage offers good nesting sites for small birds, which are also attracted by the insect smorgasbord, and the fruits, which ripen to black.



When I planted it twenty years ago, my idea was to cover this trellis with the jasmine to make a
screen.

 

As you can see, the jasmine had other ideas!  Despite failing to gain the neat screen I had planned for, I have since grown to love the plant’s non-conformist shape. Almost completely concealed in the above photo is a native beehive, appreciating the shade in the heat of summer.



In autumn, I give the jasmine a trim to let in the sun. The hive is situated on the eastern side of the trellis with a northern aspect, so it is snugly situated to pick up the winter sunlight until mid-day, while sheltering from our cold August winds.



 The triple-leaf-jasmine was slow to grow in its first year or two, and I planted some desert jasmine (Jasminum didymum subsp. lineare) on the same trellis. It is still there, but a little difficult to find among the much greater bulk of its broader-leafed cousin’s canopy.





This jasmine (and probably most of the other jasmine species) is happy to be refreshed by hard pruning. I recently decided it was time to take my plant back to basics, because I was concerned that its weight might be putting too much strain on the twenty-year-old trellis. I trimmed it down to its woody skeleton. What I learned from picking up the clippings was that despite their apparent bulk, the weight was negligible and I need not have worried. What an excellent plant this would be for a rooftop garden or large balcony - the size of a substantial shrub, but without the weight.
I removed every scrap of leaf, and for a few weeks I worried that I had overdone it. What it I had killed my beloved jasmine?!!  To my relief it has bounced right back.




As the photo shows, it is still stubbornly determined to make its bulk at the top of the trellis. Meanwhile I have cut off its flowering stems for this summer, so will have to wait another year for flowering. A gentle trim no later than March should help the new growth to thicken up still more, and give the plant time to put on a good insect-feeding display next summer.

In the wild, This jasmine often grows as a tangled shrub-like thicket, providing shelter for wildlife of many kinds. the photo below, however, shows one which has used a shrub - long since dead - as a trellis. The result is a little jasmine tree, something that could be reproduced in a garden, with the right kind of support.


 



Tuesday, December 31, 2019

SWEET JASMINE


Jasminum dianthifolium
(Jasminum suavissimum)

FAMILY: OLEACEAE
 


This little plant, like all the jasmines, can be a twiner with the ability to climb. However it can also spread underground, and is more often seen as a small, low-growing plant in grasslands. Its substantial underground root system means that it can withstand grazing, and (as seen below) attacks by a Council grader. What seem to be a group of plants in the picture probably comes from a single root.




It has what I think is the best perfume of all the local jasmines. You might like to compare it with the other local jasmine species (Jasminum simplicifolium,  Jasminum didymum subsp.  racemosum,
Jasminum didymum subsp. lineare, and the natural hybrid, Jasminum simplifolium x suavissimum), to find your own favourite. The perfume is strongest in the evenings and early mornings, which is typical of moth-pollinated flowers.




Provided they are found by pollinators, the flowers will be followed by small, succulent black fruits, which appeal strongly to small birds.

In a garden, the best situation for this plant might be an a mulched shrubbery, where it can wander at will, popping up wherever it likes. However it can be grown in many situations, including in a pot where it can be left to trail over the edge, or provided with a tiny trellis. Once established, it can be pruned as hard as you like to help it to grow into a bushy plant.

It likes the dappled light among trees, or a situation where it gets sun for only part of the day,  and tolerates all soils except heavy poorly drained clay.  It survives frost by dying down to its roots, regrowing in spring. Its lifespan is not known, but you can expect it to be long-lived.