Green Pearls

Jasminum simplicifolium
Family: OLEACEAE
If pearls came in green, I think this is what they would look like.


My stiff jasmine Jasminum simplicifolium  is laden with them at the moment.
When they ripen, they will look like this:


 and will be very appealing to fruit-eating birds.

The flowers that produced them looked like this:


Note the variation in the number of "petals". These jasmines can have anywhere between five and eight.

As with many white flowers, they would have been pollinated by moths attracted by the perfume. For those who are curious to find out whether moths are indeed the pollinators, a quick check of the perfume at night, after the day’s heat has worn off, will tell you. If the perfume is stronger (and Jasmines all have a lovely perfume), then you know that the plant has evolved to attract moths. You may even see the culprits while you are investigating.

A likely pollinator, is this big hawk moth.
 

Pollinators don't necessarily breed on the plant that produced the flowers they feed on, but this Psilogramma menephron does breed on native jasmines. (It is known as the “privet hawk moth”, because it also breeds on the introduced privet, as well as a number of other native and introduced  host plants).

Hawk moths have long tongues, and the long tube of the jasmine flower may have evolved to attract them while preventing other less effective pollinators from reaching the nectar at the base of the tube.

You need to be quick to catch a hawk moth feeding/pollinating, because these fast-flying night feeders dart in to a flower, hover (like a hummingbird) for just a split second, then dart off again.

We saw this Psilogramma menephron caterpillar on our Jasminum didymum subsp. racemosum last month.

Isn’t it a lovely thing? It was being attacked by ants at the time, and it was wriggling about catching them and biting them.

It looks almost ready to pupate. When quite ready, it would have dropped off and burrowed into the ground.

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?

Something special, in Rainy Weather.

Tar Vine Boerhavia dominii
FAMILY: NYCTAGINACEAE

Some of you will be familiar with this delightful little plant.



I photographed the one below near Wyreema,



and the one below this was at McEwan State Forest near Pittsworth. As you can see, the leaves vary a bit from place to place.



The plant itself is not showy enough to ever become popular as a garden ornamental, but is pretty, all the same. The tiny flowers are exquisite. As a romantically-inclined farm child from the Darling Downs, I was sure they would be fairy favourites.

A friend from Pittsworth sent me these photos yesterday, showing the amazing transformation of the seeds after rain. She says the little blobs which have developed to encase the seeds are “slimy”.






Aren’t they beautiful? Like little pearls! If you click on the photos, you can get a good look at the details.

On the second rainy day, the seeds are falling off, and collecting under the plant, looking "like frogspawn".


The reason for it all is that the seeds contain mucilage, which swells when wet, encasing the seed in a little damp ball to improve its chances of staying wet long enough for the newly germinated seeds to have a good chance of growing. Now would be a very good time to move some of those seeds into a bare dry patch that needs a bit of ground cover, and tuck them under a light cover of damp soil, being careful to preserve their mucilage coating. They can cope with a very tough, sunny site that gets very dry.

The mucilage has another function as well. It is designed to stick to the fur of passing mammals.This technique has helped the plant to spread itself about over much of Australia.

ADDENDUM: Since I published this blog, a correspondent has told me several other things about this plant.
The secret of its survival in hard, dry conditions is its persistent  taproot. This root is edible, and is still collected for this purpose by people living a traditional lifestyle in Central Australia. (If you want to try it, please be cautious. It may need to be cooked first). The leaves of the closely related B. diffusa are often used as a green vegetable in many parts of India.
Apparently it is unpopular with farmers, and can actually reduce the value of a farm because it is a difficult "weed" to kill by any means including poison, and tends to tangle in a plough. Pastoralists, however, regard it as a good, palatable pasture plant. Horses are said to get fat (and lazy) on it.