Wild South East

a nature blog of south-east Victoria, mostly Gippsland

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Coastal Dune Flora- Pt 2 : Herbs, grasses and scramblers

This is part 2 of a look at the amazing and resilient flora of coastal dunes in southern Gippsland. In part 1 I talked about the shrubs and trees found in this habitat and this post I’ll discuss the often less obvious flora; the herbs, grasses and scramblers.

As I mentioned in the last post on dune flora the fore dunes are usually dynamic and frequently mobile, particularly towards the beach where wind and wave action are unpredictable and often dramatic. At the base of the fore dune the vegetation is often sparse and consists of mostly grasses with some herbs, sedges and low shrubs. Common grasses in this ‘pioneer’ area include Spinifex sericeus (Hairy Spinifex) which often dominates this zone as well as Poa poiformis (Coast Tussock-grass), Austrostipa spp (Spear Grass) and Rhytidosperma spp (Wallaby Grass).

Hairy Spinifex Spinifex sericeus

Hairy Spinifex Spinifex sericeus

A small sea cliff on a dune with Coastal Tussock Grass at the top.

A small sea cliff on a dune with Coastal Tussock Grass Poa poiformis at the top.

In the mid to late 1800’s many dunes were partly cleared and grazed and an initiative to restabilise them was devised which unfortunately involved the introduction of Marram Grass Ammophila arenaria from Europe. This species has since established itself extremely well and has become a serious environmental problem on coastal dunes.

Marram Grass, a serious weed on coastal dunes

Marram Grass Ammophila arenaria, a serious weed on coastal dunes. Here it smothers a native Dune Thistle.

Another serious weed to be found on the lower part of the fore dune is the Mediterranean Euphorbia paralias (Sea Spurge) which was also introduced for dune stabilisation. This widespread weed has a long tap root weed and can alter the shape of the base of the dune to a steeper angle, making it more prone to being undercut by waves.

The introduced Sea Spurge has the ability to alter the shape of dunes.

The introduced Sea Spurge (foreground) has the ability to alter the shape of dunes.

Extending up the face of the fore dune towards the top you often find amongst the shrubs scattered native ground covers and herbs such as the extremely hardy succulent Carpobrotus rossii (Ross’s Noonflower), Senecio biserratus (Jagged Fireweed) and Actites megalocarpa (Dune Thistle).

Ross's Noonflower Carpobrotus rossii

Ross’s Noonflower Carpobrotus rossii, a type of Pigface

Jagged Fireweed Senecio biserratus

Jagged Fireweed Senecio biserratus

Dune Thistles (see above photo of Marram Grass) can look a lot like the introduced thistles and are in the same family Asteraceae. Unfortunately this species may often be mistaken for the weedy variety and I was once told by a person from a large government agency (insert name here) that they got volunteers to remove hundreds of these along a section of coastline before I mentioned to them they are native! Oops.

Once you extend over the crest of the dune the vegetation changes considerably and amongst the shrubs you often notice the abundance of scramblers and climbers extending down the face of the hind dune such as Clematis microphylla (Small-leaved Clematis), Muehlenbeckia australis (Climbing Lignum), Rhagodia candolleana (Seaberry Saltbush) and Tetragonia implexicoma (Bower Spinach). The latter two often grow up to smother other shrubs and can often form dense ‘blankets’ over vegetation and create an important habitat for ground dwelling fauna and refuges for small birds.


Climbing Lignum Muehlenbeckia australis

Small-leaved Clematis Clematis microphylla

Small-leaved Clematis Clematis microphylla

Seaberry Saltbush Rhagodia tetragonoides

Seaberry Saltbush Rhagodia candolleana

Bower Spinach Tetragonia implexicoma

Bower Spinach Tetragonia implexicoma

The soil here is remarkably different too and less mobile due soil fungi, herbs, grasses and other vegetation taking advantage of the protection from wind to bind the soil together.

Mosses and herbs established on stable soil

Mosses and herbs established on stable soil


As you reach the base of the hind dune the vegetation often consists of various climbers (as mentioned above), grasses, herbs and sedges mixed with shrubs and small trees. Grasses regularly encountered are Distichlis distichophylla (Australian Salt Grass), Poa spp (Tussock Grass) and Lachnogrostis spp (Blown Grass).

Australian Salt-grass Distichlis distic

Australian Salt Grass Distichlis distichophylla

Lepidospermum concavum (Sandhill Sword-sedge) is a broad-leaved sedge which can dominate some areas of this zone and is important for some moth species whose larvae feed on the leaves.

Sandhill Sword-sedge Lepidosperma concavum

Extensive area of Sandhill Sword-sedge Lepidosperma concavum (centre of photo) at the rear of a dune.

Australian Hound's-tongue Cynoglossum austral can be common at the base of hind dunes

Australian Hound’s-tongue Cynoglossum australe can be common at the base of hind dunes

Unfortunately the base of the hind dune is often choked with weeds such as African Boxthorn as well as introduced grasses (as in the above photo) and many smaller native species struggle to establish.

African Boxthorn Lycium ferrocissimum infestation at the back of a dune system

African Boxthorn Lycium ferrocissimum infestation at the back of a dune system

This hind dune zone often tends to merge in with other habitats, typically coastal woodland, grassland/sedgeland or swamps and can often include many of the same plants as well as other completely different species.






Coastal Dune Flora -Part 1: Shrubs and trees

The flora of coastal dune systems deserve a lot of respect. Millions of years of evolution and adaptation has given these plants an unusually high tolerance to strong salt-laden winds and soil which is frequently mobile and low in nutrients. This harsh environment is also generally lacking in water and what water is available is usually salty or brackish. Plants here have developed an arsenal of physical adaptations to these conditions such as leaves designed for low water loss, prolific seed dispersal and general growth habits, amongst many others.

The first thing you notice when looking at a coastal dune is the vegetation on the fore dune (the side facing the sea) is typically of similar height and usually in a dense, stunted form.


Stunted shrub vegetation consisting of predominantly Cushion Bush, Coastal Tea Tree, Coast Beard Heath, White Corea and Coastal Wattle.

The pioneer zone (the lower section closer to the beach) typically consists of sparse vegetation including grasses, herbs and some shrubs. These are the frontline protection for the rest of the dune and plants here typically have strong stems and a network of mesh-like root systems which stabilize the lower dune. They are, however, subject to frequent high tides or storm surges which destabilises this zone. Once you move over the crest of the dune away from the sea to the hind dune the vegetation begins to increase in size and diversity and often becomes more open. Here the soil has become more stable due to the decrease in wind and the increase in herbs, groundcovers, mosses, lichens and fungi which bind the soil. The water holding capacity also increases due to the layer of humus in the soil.

One of the most successful and prominent species in Gippsland’s dune systems is the Coastal Tea Tree Leptospermum laevigatum.


Coastal Tea Tree Leptospermum laevigatum produces a prolific amount of flowers.

This species’ defences include thick, leathery leaves and a habit of growing in dense stands, both of which help to reduce water loss. It also produces a huge number of seeds in each capsule and this increases the chance of successful germination. On the fore dunes Coastal Tea Tree tend to grow in dense, stunted forms whereas behind these dunes they can form tall, tangled thickets up to 8m in height.

Another common species is the Coast Beard Heath Leucopogon parviflorus.


Coast Beard Heath Leucopogon parviflorus is a slow growing but hardy species which produces masses of small flowers in spring.


This also has stiff, leathery leaves and like the Coastal Tea Tree it can be found growing in stunted forms on the fore dune as well as taller forms in more protected areas on the hind dune. It doesn’t produce the amount of seed as Tea Trees, instead forming white fleshy round fruits.

The Coastal Wattle Acacia longifolia ssp sophorae is a brilliant stabilizer of sand dunes and is often one of the pioneer species on newly formed sand drifts. Wattles usually develop a long, deep tap root and also have the ability to fix nitrogen from the atmosphere making them one of the heavy-weights of the dune system. It’s these characteristics which make this species a major environmental problem outside of it’s natural range.


Coastal Wattle Acacia longifolia ssp sophorae


Coast Banksia Banksia integrifolia is one species which, although quite hardy, hasn’t developed the degree of tolerance to salty winds as the previously mentioned plants. As such it is often sparse and stunted on the fore dune but can be prominent and occasionally very large on the land side. Coastal Banksia flowers most of the year but rarely in summer and honeyeaters especially love the flowing nectar it produces.

Coastal Banksia Banksia integrifolia

Coastal Banksia in full bloom

One distinctive species in the dune system is the Cushion Bush Leucophyta brownii.  This rounded and very compact shrub has whitish-grey foliage and tends to grow in exposed sites. Due to its compact form it helps to protect and bind the soil as well as offering refuge for small animals. The leaves are reduced and flattened against the stem which helps it reduce moisture loss.


The compact nature of the Cushion Bush Leucophyta brownie

Other common shrubs or trees found on coastal dunes include:

Boobialla Myoporum insulare. Another successful species this medium sized shrub has developed waxy leaves which again protect it from losing moisture.

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Waxy leaves of the Boobialla Myoporum insulare


Drooping or Coast Sheoak Allocasuarina verticillata. This is a large shrub or small tree almost predominantly found on the backs of dunes and all members of this genus have evolved highly modified branches and leaves. The teeth-like leaves are reduced to extremely tiny whorls at the nodes of the long and slender branchlets. As the leaves are so small the branchlets actually perform most of the function of photosynthesis thus reducing the amount of water lost through transpiration. Due to this fact Allocasuarinas have colonised a large part of Australia including many dry and extreme environments.


Coast Sheoak Allocasuarina verticillata


Cone, flowers and leaves of Coast Sheoak.

White Corea Corea alba. This low shrub grows in all parts of the dune system and develops white tubular flowers in late winter to spring which small honeyeaters particularly like.


White Corea Corea alba.

White Corea Corea alba

White Corea Corea alba

Although coastal dune systems are extremely hardy they are no match for the ignorance and greed of property developers and as such have been devastated in many areas for housing and ‘aesthetics’. In fact the role these dunes play is immense and include protecting inland environments from intrusion from high winds, salt-laden air and storm surges, not to mention the biodiversity and ecology of these areas. Dunes also provide a reservoir of  sand to replenish beaches in the event of destructive weather events.

Upcoming posts will include the other flora of these fascinating dunes.