Plant of the month – Aug 2017

SMOOTH RICEFLOWER

(Pimelea glauca)

(Photos: E. Cousins; growth habit, flower cluster; Cape Jervis)

Come spring, you will see this little shrub flowering freely around Cape Jervis. It has 1 cm long blue green leaves, which are arranged very symmetrically around the many stems. The tiny, creamy-white flowers are arranged in balls about 3cm wide, at the end of those stems … you can see how many little flowers there can be in a flower cluster in the second photo above. Each little flower has 4 petals and yellow-tipped stamens. Under each cluster you will find four leaves (called floral leaves) which are slightly larger than the stem leaves; the inner two should have hairy edges. So look for tidy little shrubs covered in white this spring as you walk around Cape Jervis, and see if you can identify this riceflower.

Weed of the month – Aug 2017

COMMON BRIDAL CREEPER

(Asparagus asparagoides)

This creeper smothers native plants. Dormant over our dry summers, it sends out long, vigorous, twining stems after autumn rains. These form a thick, dense mat spreading over shrubs and up trees. The root system consists of a central stem, with many tubers attached. Like the leaves and stems above ground, these underground tubers also form a thick mat. In fact, the root system can be up to 90% of the plant’s total mass.1 So while the creeper is preventing sunlight reaching its hosts above ground, the root system is preventing root growth of plants and seedlings below ground. The green leaves appear in groups on short side branches on the long stems. White flowers in spring are followed by berries which ripen to red. These contain black seeds… one plant can produce thousands. Birds feed on the berries, and excrete the seeds elsewhere, helping the plant spread. Biological controls (rust fungus and beetles) are often used to limit the spread of this pest; digging doesn’t guarantee removal of all the tubers. For more information see the PIRSA fact sheet http://pir.sa.gov.au/__data/assets/pdf_file/0010/145594/Fact_Sheet_BridalCreeper.pdf

1 Bridal creeper (Asparagus asparagoides) weed management guide, at http://www.environment.gov.au/biodiversity/invasive/weeds/publications/guidelines/wons/a-asparagoides.html

 

 

Plant of the month – July 2017

ANNUAL BULBINE LILY

(Bulbine semibarbata)

(Photos: from https://florabase.dpaw.wa.gov.au/browse/profile/1366, https://www.plant-world-seeds.com/images/item_images/000/001/551/large_square/BULBINE_SEMIBARBATA.JPG?1495388088)

Now doesn’t that yellow brighten up a gloomy winter’s day? You might have to wait another few months to see it around though.  The flower of the bulbine lily appears in summer, with 6 bright yellow petals and some inner stamens. Three of these stamens are hairy, which you might be  able to see in the second photo above.  And since the flowers are only about 1 cm across, you might need a lens to see them in real life too! The entire plant is only ankle high, with cylindrical, fleshy leaves (like those of an onion only smaller and brighter). Above the open flower you would normally see more unopened flowers… a bit like a hyacinth: some dying, some open, some unopened flowers along a stem. So come summer, look out for these bright, rare plants along the coast in rocky places, or in the mallee, and enjoy!

Weed of the Month – July 2017

GAZANIA

(Gazania rigens, Gazania linearis)

(photo of Gazania linearis from http://www.naturalresources.sa.gov.au/adelaidemtloftyranges)

We thought it would be beneficial to revisit some of the weeds we have looked at before, such as gazanias. These familiar natives of southern Africa can spread easily in coastal communities, because they withstand salt-laden winds and grow well in sandy soils. They also harbor white snails! Gazanias flower in bronze, yellow and orange shades, often with black markings.  Gazania linearis has short, mostly underground stems and dark green leaves, while the stems of Gazania rigens form a mat above ground, and leaves are paler, more silvery. Either can form a monoculture, outcompeting native species for nutrients and moisture.

Gazania is now a declared plant under the Natural Resources Management Act 2004; it can’t be sold at nurseries etc., and it can’t be transported around the state. The Southern Fleurieu Coastal Action Plan gave gazanias a “priority threat rating” of 8, making them the second highest rated weed in the area, behind bridal creeper. If you want to grow something with similar colours, try a native such as the pretty, yellow Common Everlasting Daisy (Chrysacephalum apiculatum).

(For control measures, see the gazania fact sheet from Natural Resources Adelaide & Mt Lofty Ranges, which can be downloaded  from http://www.naturalresources.sa.gov.au/adelaidemtloftyranges; search for gazania, 2017)

Plant of the month: June

COAST SILVER WATTLE (WIRILDA)

Acacia uncifolia, previously Acacia retinodes

 

 (Photo: E. Cousins, Cape Jervis; foliage, flower cluster.)

This acacia is a good one for attracting birds, butterflies and other insects to your garden. You can’t see this in the photos above, but the trunk of this upright tree is rough, and dark brown in colour. What you can see though are the long thin leaves, with a central vein. These leaves can be up to 20cm long, though the ones on this Cape Jervis specimen were much shorter. They are a green to grey-green colour, and contrast well with the creamy yellow flower clusters. The flowers form balls which then form in clusters along a common stalk.  Like the leaves, the following seed pods can also be long… up to 14cm! The tree produces a gum, which Indigenous peoples softened in water, then ate for relief from chest pain.

 

Weed of the month: June

LAVENDER

(Lavandula species)

(Photos: E. Cousins; 3 small plants along a walking trail, leaf and flower of French Lavender)

Hardy lavenders are plentiful in our gardens, particularly the English and French varieties. They may have self-seeded in your garden, which is great, but they also self-seed in bushland, with seeds carried on boots, or by wind, etc… not so great! The first photo above shows three healthy seedlings on the edge of a walking trail, over about 1 metre of path.

Easily identified by their aromatic smell and purple flowers these bushy shrubs grow to about knee high, with a dense habit. The leaves of the French Lavender shown are narrow with many lobes on both sides of the centre rib. Another weedy variety, Topped Lavender, has smooth-edged leaves; their flower spikes are topped with some very obvious purple ‘flags’ at the top. Lovely in gardens, with many uses … we just need to make sure that’s where they stay.

Carolyn’s corner: May 2017

Weeds – some are worse than others – but why?

Our weed of the month for May is not a big threat at Cape Jervis – yet, and maybe never, but we will watch and act if necessary. The worst important weeds for any given area can be different but there are formal processes for classifying weeds. There are 32 weeds that have widespread impact, and are listed as “Weeds of National Significance”, based on their invasiveness, potential for spread and environmental, social and economic impacts (http://www.environment.gov.au/ biodiversity/invasive/weeds/weeds/lists/wons.html). We have two of these on site, bridal creeper and boxthorn. Each state also has its own “Declared Weeds”, that land holders are required to control on their own land (http://www.pir.sa.gov.au/biosecurity /weeds_and_pest_animals/weeds_in_sa). Other weed threats, such as Acacia cyclops are more localised. Woody weeds such as olive and cyclops are a BIG problem in the biodiverse coastal heathlands at the Cape because of their rapid growth and their smothering effect. Come out with us for a few hours and we can show you the benefits of removing these weeds and help you recognise young seedlings so they can be removed before they become a big problem.

Photos: hand-pulled ‘cyclops’ seedlings (E. Cousins); resprouting poisoned olive; a sea of baby olives (C. Schultz).

Plant of the month: May

STIFF CHERRY

(Exocarpus aphyllus)

(Photos: E. Cousins, plant; C. Schultz, close-up of stem, at Cape Jervis)

This plant is from the same family as the quandong (Santalaceae) though you wouldn’t think so from the differences in the fruit or foliage!

Aphyllus’ is from the Greek, meaning ‘without leaves’. There are in fact leaves on the thick, rigid branches, but they are TINY (less than 1mm), more like scales!  And expecting a cherry-like fruit or two? Try a small black ovoid (egg-shape) with a squashed creamy-red base (hence ‘Exocarpus’:outside the nut’). Even the yellow flower clusters are small, at less than 4mm. These are present over spring and early summer, and protrude from the branches on short stalks. Tiny leaves, tiny flowers, tiny fruit… yet the olive-green bush can grow over 3.5m tall, with heaps of branches! Although common in many other parts of Australia, it is classed as ‘vulnerable’ on the Fleurieu Peninsula.

Weed of the month: May

PINCUSHION HAKEA

(Hakea laurina)

(Photos: E. Cousins; foliage, young flower and bud; bees on mature flower.)

Such a beautiful flower, and such beautiful foliage! A native of WA, this makes a lovely garden plant…just not so lovely when it escapes into local native bushland! The small bushy tree has flat blue-green leaves, reminiscent of acacias or eucalypts. The edges of the leaves can be tinged with red, while strong vein markings give a striped look so the leaves are fairly distinctive. The autumn and winter flowers though give the plant its common name. On breaking out of their capsules the white protruding stamens are firstly bent, then straighten out like pins from a red base. As you can see from the second photo above, the bees LOVE the nectar these flowers produce (there were more than one dozen of them clustered in that one flower)! Grow one in your own garden, but please, make sure it doesn’t spread elsewhere!

Plant of the month: April

KNOTTY-BUTT PASPALIDUM

(Setaria constricta)

(Photo: E. Cousins, Cape Jervis; habit, stem)

This summer grass was pointed out to us by Corey Jackson (Yankalilla Council/NRM) on our site at Cape Jervis. Why knotty-butt? Well, the rootstock of the grass apparently looks knotted! Why ‘constricta’? Read on! Classified as ‘near threatened’, this grass seems to be doing well this year with the extra rain and cooler temperatures. It grows as a tussock pretty low to the ground at about 20-30cm in height, with a width roughly the same. The grass blades are just 2-3mm wide. The stem bearing the seeds (the ‘inflorescence’) is only about as high as the plant, but much branched. The seeds themselves have no bristles, are about 2-3mm long and with a constriction about ¼ of the way up from the base… so take your magnifier along if you go looking for this one! Possibly a good plant for finches, wrens, and other grass-seed eating birds. Let us know if you see any birds eating the seeds!