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:

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:

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:

Another local with simple, opposite leaves is this one.

Small Fruited Mock Olive, Notelaea microcarpa - for more details on this plant see:

This one has simple, alternate leaves:

Scrub Boonaree, Alectryon diversifolius - for more details on this plant see:

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:

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:
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:

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

Jasminum didymum subsp. racemosum

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


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


Jasminum dianthifolium
(Jasminum suavissimum)


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.

Tuesday, June 4, 2019

Is Cullen tenax seed edible?

I was asked this question after my post on Cullen species,

None of my bushfood books mention it, but I found several internet references to recipes for using the seeds in cooking (a cake, and biscuits).

I could find no references to aboriginal use of it, or to any testing having been done to establish the safety of eating the seeds.

I am aware that enthusiasm for bushfoods has led to some experimentation with foods that may not be safe to eat, so would not suggest that anyone do it, without having some further knowledge.

Can anyone help us here?

Friday, February 8, 2019

Devil’s Marbles

Eremophila debilis

Down south, this plant is known as Winter Apple - and that’s when it usually fruits.

However, like so many of our local native plants, Devil's Marbles is an opportunist. By means mysterious, it decides when its chance of producing a new generation is at its best, and this year it has chosen February. I would love to think that it "knows" rain is coming!

For those who would like to grow this useful and hardy ground cover plant, now is a good time to look for fruits on your properties and on roadsides.

The best technique is to plant one seed per small tube, in good-quality potting mix. Cover it to a depth equal to the diameter of the seed, and keep it damp until it germinates.  Some people say they have good results if the flesh is left on the seed, but I prefer to remove it. You can do this by sucking your seed clean. This is regarded as a bush tucker plant, and is quite safe. I leave it to you to decide whether you like the flavour, which I find quite acceptable (if unexciting) provided the fruit is very ripe.

Once the plants have reached a good size, they are can be planted straight into the garden.

To find a more detailed article about this plant, use the white Search box at top left.

Monday, February 4, 2019

Desert Jasmine

Jasminum didymum subsp lineare (Jasminum lineare)

Despite its name, this is a plant we see on the black soil of the Darling Downs. As the name suggests, it is very drought hardy indeed.

It can be distinguished by its triple leaves from Sweet Jasmine, Jasminum dianthifolium, a plant whose simple leaves look much the same. Sweet Jasmine is a low-growing plant that spreads by underground stems.

Desert Jasmine is a variable plant. In full sun, it grows as a shrub about 60cm tall.

If it finds itself close to suitable support, however, its stems will take to twining, and it becomes a small shrubby climber. This means that it may not grow quite as you expected.

If a shrub is what you want, a bit of discipline with the secateurs can keep it in order if it shows signs of turning into a climber. Otherwise it can be left to express its own creative nature among garden shrubs, on a trellis, or in revegetation or wildlife corridor planting.

Desert jasmine is a delight in the garden, because the tiny flowers have a strong jasmine fragrance.  Like all native jasmines, they attract native bees and other small insects.

The little soft black fruits are very appealing to birds.

Its favourite sites are those which provide it with partial shade.

It is frost hardy.

Monday, January 28, 2019

Triangular Clubrush

Schoenoplectiella mucronata (Schoenoplectus mucronatus, Scirpus mucronatus)

This small species of perennial rush can’t be mistaken for any other plant. It has distinctive yellow-green triangular stems, each ornamented in summer with a neat cluster of golden-brown cone-like “clubs” about 2 cm from the stem-tips. (They resemble posies, and look like something that might be carried by a bridesmaid with attitude!)

The plant is worth growing if for no other reason than for use in floral arrangements.

Shown here in a bird bath, it is easily grown in any small container which holds water. It grows rather fast, so a pot of it is best refreshed each spring by having three quarters of the plant, and its rather dense root ball, removed and replaced with fresh soil or potting mix.

In a pond or dam, triangular club-rushes form a low thicket which grows from the water’s edge to the point where the water is too deep for them, which is at approximately 30cm. They will survive deeper water provide it is temporary, such as in a flood.

It also tolerates some drying out (as shown here at Cressbrook Dam) but probably needs good wet soil not far below the surface.

In creeks, it will only grow where there is permanent water, which must be either still or slow-flowing.

Triangular clubrush is a frog-favourite, and particularly useful for small garden ponds in wildlife friendly gardens.

This is one of the few shade-tolerant rushes. It can survive in full shade provided it is well lit (though it does tend to get leggy), and is equally happy in full sun.

It is also frost hardy.