ROCK WATTLE

(Acacia rupicola)

(Photos: C. Schultz; Rapid Bay)

There are lots of prickly wattles; you are probably used to seeing one called Acacia paradoxa (Kangaroo Thorn). This is another prickly one, also with ball-shaped yellow flowers on short stems from the leaf base. However, whereas Acacia paradoxa has thorns growing from the leaf bases, it is the leaves themselves that are prickly on Acacia rupicola, the rock wattle: there is a sharp point at each leaf tip. Those leaves are lance-shaped, about 10 times as long as they are wide: 2.5cm to 2.5mm! The shrub itself grows to about 2-2.5m, is rigid and glabrous (smooth). Young growth can be a bit sticky, and the bush can have a smell of resin. The books say flowers finish in November, so the long curved brown seed pods should be visible in January. Nature doesn’t always read the books – these photos at Rapid Bay mid December had both flowers and ripe seedpods. Don’t get stabbed by those leaves when harvesting seed, and look carefully for insect life! This well camouflaged orb- weaver is the same colour as the dying flowers.

SALTY ICE PLANT

(Mesembryanthemum crystallinum)

 (Photos E. Cousins, Cape Jervis; young plant, close up of leaf, flowering plant showing summer stress)

We have featured this weed before, but a recent posting of its picture on SA Natureteers with a request for identification prompted us to revisit it. The response to the posting from many readers was immediate: GET RID OF IT! The Diggers Club^[1] states this plant “may naturalise in coastal areas” and “Not for SA”…and anyone who wanders around Cape Jervis over winter-summer can see why! This annual herb is a prostrate succulent, about 10 cm high.  Its leaves are covered in large glistening lumps, or bladder cells of water, giving the plant its common name. The plant grows rapidly over winter, but its growth slows in spring. Dry summers can kill the plants, but by then, its seeds have probably already been spread by rabbits (who eat them). Ice plants have several characteristics which make life hard for their neighbours: they can absorb a lot of moisture from the soil, outcompeting most other species; high levels of nitrate which build up under the plants can be harmful to other species; salt accumulates in the plant over its lifetime, and this is then released into the soil when the plant dies back in summer. Less salt-tolerant species suffer because of the salt which can inhibit both grown and germination of native species.

^[1] https://www.diggers.com.au/shop/edibles/salty-ice-plant/s601/

WEDGE-LEAF DAISY

(Brachyscome cuneifolia)

(Photos: C. Schultz; Whole plant, flower and seed; Lands End, Cape Jervis)

There are several pretty daisies on the Fleurieu – the minnie daisy, the satin everlasting, and this one. It is only shin high, with a rosette of leaves at the base. ‘Folium’ means leaf and ‘cuneus’ means wedge, in Latin, hence the common name. The leaves are lobed, and pubescent … which is a botanist’s way of saying they have hairs. Actually, the ‘…come’ part of Brachyscome comes from a Greek word for hair, but the hair on a seed which aids dispersal, not the hair on the leaf! The spring flowers are like your typical daisy… white with a yellow centre, so how can you tell this daisy from others? Well, the SA Seedbank helped out here. You actually need to see the seeds to be sure you have the name right. The seed are flat brown ovals, with tiny hairs on broad margins. The wedge-leaf daisy is rare on the Fleurieu, so we are hoping the seed germinate!

COMMON or SOWN VETCH

(Vicia sativa)

(Photos: E.Cousins, Cape Jervis; a stem, with leaves and seedpods; back of leaf)

There are at least three weedy vetches: the common (or sown), the hairy and the spurred. All are weak annual herbs, with long twining stems. This particular one, sown vetch, can be identified by several leaf characteristics. Firstly, leaves are paired and opposite each other on the stems. Secondly, each of the leaves has a broad flattish top, with a point at the centre top. This can be seen clearly in the second photo above. Also, the leaves are hairy, front and back, also clearly visible in the second photo! The springtime flowers look like those on a sweet pea, but occur singly or in pairs at a leaf junction, and not on a long stem like the sweet pea. These flowers are purply-red to purple in colour. The seedpods also look like those on sweet peas, etc… long straight pods that go brown on ripening. The picture above on the left shows that multiple pods on a stem are common. Originally a fodder plant, this is now a weed over south-east SA.

SCENTED GROUNDSEL

(Senecio odoratus)

(Photos: E.Cousins; stems; flower head; leaves)

Senecios come in many forms, and this month we are featuring both a goody and a baddy. Both have clusters of yellow flowers over summer. However, those of the scented groundsel (our goody) don’t have a disc of long petals; the flowers tend to form tubes with a ‘fluff’ of short (4-6mm) petals on top. Also, the leaf shape and colour is very different in our two Senecios. The dull grey-green leaves of the native scented groundsel, Senecio odoratus, are oval-shaped, with a very distinctive vein down the centre. They are quite firm. The edges have fine teeth at the edge (whereas the South African daisy, Senecio pterophorus has larger indentations on the edges). The top of the leaf is fairly hairless, but the back looks like it is covered with fine cobwebs. Where the leaf clasps the stem, the leaf curls in on itself a bit.

The scented groundsel makes a good host plant for the endangered native parasitic plant Orobanche cernua var. australiana (see plant of the month, Jan 2017).

SOUTH AFRICAN DAISY

(Senecio pterophorus)

(Photos: E.Cousins; weed habit; a stem; close-up of wings; leaf comparison)

This is another weedy Senecio. It is tall (up to 1.5m high), with multiple stiff stems. These can become quite woody. Yellow daisy-like flowers appear in summer in groups at the top of the stems.  It is really easy to identify this Senecio because where the leaves join the stem, they keep going down that stem to form wings (see  3rd photo above).  So when you run your hand down the stem you can feel these as flappy bits.

The leaves themselves are lance-shaped, and toothed. They are darker on top, pale underneath. The 4^th photo compares the leaves of the weed (on the right) with the leaves of Senecio odoratus (left) (see Plant of the Month).

GOLDEN WATTLE

(Acacia pycnantha)

(Photos: E. Cousins, shrub, leaf, flower; Cape Jervis)

September 1 is Wattle Day, and the photos above illustrate why we celebrate it. That colour jumps out at you and just has to brighten your day!  And it is no wonder this particular wattle was chosen as the National Floral Emblem of Australia in 1998. ‘Pycnantha’ basically translates to “thick, dense, compact flowers”. Hard to know if the ‘thick’ and ‘dense’ refer to a single flower ball, or the profusion you can see in the clusters above, isn’t it? The tree itself is not large, at up to about 8m. Its trunk can be dark, almost black, in southern SA. The leaves are long and thin, curved with a dominant central vein. Flowers present as balls of bright yellow over winter-spring. Later, seed pods will form. These are quite long and narrow (about 12cm by 5mm), brown and straight. It can take 5-6 months for these pods to mature and release their black seeds.

DIOSMA

(Coleonema pulchellum)

(Photos: C. Schultz, flowers, leaves, shrub)

This is a beautiful garden shrub…so why have we chosen it as our “Weed of the Month”? Well, this plant was seen NOT in a garden, but along the drain in the reserve  near Jakaka Ave. The plants are likely garden escapees, although we haven’t had time to check nearby gardens yet. The definition of a weed is a plant that grows where it shouldn’t. Who would have thought gazanias, arum lilies or olives would have become the pests they are? Lovely in gardens, big trouble in remnant vegetation. Back to Diosma…. The aromatic shrub grows about 1m high, with a compact form. Masses of small star-shaped pink flowers are produced over winter-spring, on feathery foliage. Drought and frost tolerant, these South African natives will look great in your garden. Just keep it there – pruning after flowering is a great way to stop seed spreading!

NATIVE or AUSTRAL STORK’S-BILL

(Pelargonium australe)

(Photos: C. Schultz, flowers; a plant at the end of summer)

Another of the little herbaceous plants, this is rare around Cape Jervis. It will only grow about ankle-high, with leaves about 3cm across, so it could be easy to miss. However, it will be flowering over late spring and summer, so watch for the clusters of pale pink flowers then. They will have purple-red veins to help you spot them! The clusters sit above the plant, so that’s another help. Notice how the flower petals separate out as a group of two at the top, then three below. This is a typical feature of pelargoniums. The leaves are pale green with velvety hairs; leaf stems (petioles) are long. The roots of these butterfly-attracting little pelargoniums were an indigenous food source. They like coastal dunes and arid areas, so if you have sandy, free-draining soil, you might like to try these. Prune them hard after flowering to encourage new growth.

SOFT CRANE’S-BILL

or DOVE’S-FOOT

(Geranium molle)

  (Photos: E. Cousins: flower; C. Schultz, plant)

We were confused by this one when we first saw it; for a little while we thought it was a non-weedy native geranium, called Geranium solanderi (Australian crane’s-bill). What gave it away though was a good look at the leaf and flower shapes…and the fact that it did, quite literally, grow like a weed!! The soft crane’s-bill has leaves with a circular outline and lots of lobes not deeply divided (incisions go only a short way towards the leaf stem). The leaves of the Australian crane’s-bill, in contrast, have 5-7 lobes, deeply divided, with each lobe having 3 smaller lobes. How else will you know the weedy one? Stems have long, soft white hairs growing along them (‘molle’ is from the latin for ‘softly hairy’). Also, check out the flowers in spring-summer. They occur in pairs. As you can see in the photo above, flowers have five deeply notched pink-mauve petals around a cluster of dark stamens. The second photo above illustrates how small the flowers are in relation to the leaves… the flowers are only about 8-10mm in diameter. Flowers are followed by fruits with a long beak, the crane’s bill.