The 148ha reserve is about 10km south of Pingelly where the Hotham River crosses the Great Southern Highway. Before European settlement, this area was particularly productive for Noongar people, having freshwater pools teeming with fish, gilgies, birds and animals. It is also the location of the ill-fated Pingelly town dam.
​Land clearing for agriculture caused the river and pools to silt and become salty, but the reserve is still an interesting and attractive place.
​I found this dolerite hand axe ,which fitted well in my hand, in the bed of the river. I left it in the reserve.

To enter the reserve turn into a side road/ parking bay at the sign just before you cross the Hotham River bridge going to Pingelly. All roads and trails through the reserve are dead end. About 400 metres along Lange Road is an unmarked track to the north. Cars can drive in to an obscure roundabout, which is a good spot to stop to explore for wildflowers. Soon after, the track becomes sandy - only suitable for 4WD vehicles. Keeping to the left the track ends at the Hotham River. Remains of the dam retaining wall is a 450 metre moderately difficult  walk through weeds and bush west along the river bank. 

This remarkable reserve has three main landscape types

• 1 The Hotham River, comprising a series of channels where the river     has changed course.


• 2 Adjoining sand dunes to the south.


• 3 An ephemeral pool adjoining the dunes then an upward slope of woodland, balgas and scrub overlying sand over gravel or clay and gravel soils.

  

To the east of the reserve is a large dune-surrounded saline wetland. Banksia sand dunes adjoining the river are uncommon in this area. Adjoining examples are Kokeby and the Yenyenning lakes to the north, Lake Yealering to the east, and Lake Toolibin to the southeast. Ancient land movements blocked and diverted ancient rivers to create lakes and wetlands at these places.
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This wetland marks the junction of the Hotham River South, Calcoran Brook, and Hotham River North on the northern edge of the Hotham River catchment. North and South Hotham rivers make a U-turn at the reserve to flow west/southwest, and there are unusual ephemeral ponds on the upside of dunes.

​So, what caused the Hotham South River to take a sharp turn here and why are there dunes and wetlands?  My simplified explanation follows.

What created this landscape?
This region is underlain by a  stable piece of continental rock called the Yilgarn Craton, which is mainly granite and gneiss, some of the world's oldest (over 3 billion years) rocks. As the craton formed, then joined and separated from others in supercontinent cycles, the bedrock cracked. These cracks are faults, and dolerite dykes (where magma beneath the continent has squirted up into the gaps. This area has more dykes than usual.
About 540 million years ago Australia was connected to the supercontinent Gondwana by Greater India to the west, and Antarctica to the south. Mountains associated with these connections eroded away to leave a subdued landscape. In this area, land sloped gently to the coast, but waterways often deviated along underground faults and dykes.
India gradually separated from WA creating a rift valley (the Swan Coastal Plain), which received sandy sediments via west flowing rivers from a divide around Corrigin.

​66 million years ago the Darling Range gradually rose up as a range of ridges east of the Darling Fault. An associated valley on the eastern edge of the range shows as a line of waterways roughly following the Great Southern Highway from Cuballing (Hotham River South), then up to Dalwallinu (Avon and Mortlock Rivers).
This and a possible east-west uplift just south of Pingelly, blocked rivers upstream of the reserve to create a lake. During periodic geological climate changes the lake filled and dried. In arid climate phases, sand blown from the dry lakebed formed dunes that were colonised by Banksias.
Eventually the river cut through a rise on the western side of the lake leaving the dunes and wetlands that exist now.

​The last feature is the seasonal pond on the upside of dunes in the reserve. Why would sandy dunes hold back water?
The answer is revealed in a radiometrics map. The red colouring in the image indicates a large dolerite dyke underneath the river channel and dune area. Dolerite weathers to reddish clay soils. In winter, subsurface water flowing down from sandier soils to the south meets less permeable dolerite clay and rises to the surface – hence a pond adjoining the dunes.
​Dolerite dykes are frequently found on the downside of salt areas, and may have also influenced the river direction.

Exploring the Reserve
Despite bring mined for sand and gravel and once having tracks associated with the pump and reservoir, there is a diverse range of lanscapes and vegetation which is mostly in good condition. I thoroughly enjoyed walking through the bush, but inexperienced walkers could become lost, and as in all our bush, kangaroo ticks may be a problem if one walks through vegetation in late spring, summer and autumn.
Orchid lovers can enjoy the range of spider and other orchids by exploring open land adjoining Lange Road.

Note that all bush tracks are sandy and potentially boggy. Only drive cars into area 2 to where there is a turn around spot. If using a 4WD please drive slowly and sparingly as this country is easily destroyed. Note, there is dieback in bush to the east of the reserve. Do not drive off tracks.

Area 1 gives a good cross section of the gentle slope down to the dunes. Mostly it is fairly easy and attractive walking country. Apart from a couple of small breakaways, soils are mostly sand over clay/gravel underlain at depth by granite or dolerite bedrock. Vegetation varies according to bedrock, with thicker bush and more orchids/other flowers on  paler sandy soils. 

​You can also often tell soil types by change in ant hill colour as you walk.There is a small group of Caladenia roeii clown orchids on the upslope of the road between the two low rises.

Area 2. Drive down the unmarked track and park at the (indistinct) roundabout.
2a is attractive open woodland on the upper side, which has a fine display of Chapmans Spider Orchids in September

2b is a short walk west from the parking loop. The ephemeral pond bounded by a line of Melaleuca phoenicia shrubs (ex Callistomen phoenicous) then dunes, is a geological oddity. It was once fresh, but has become slightly saline due to salt released from the subsoil of cleared land at the top of the slope. Most winters it hosts wetland plants, algae, and aquatic invertebrates. 

2c is a band of low sand dunes and interdunal hollows as you walk towards the river. Landscape and vegetation varies depending on depth of sand, with many different types of shrubland, but there are few orchids. Dunes consist of Banksia prionotes acorn banksia, Banksia attenuata candlestick banksia, and Allocasuarina huegeliana (rock sheoak) with little understorey.
​Interdunal areas are shrublands which vary greatly depending on the depth of sand over clay, and moisture availablity. They  are attractive in late spring due to the range of flowering species, which include some that are locally rare (e.g. Calytrix acutifolia, Grevillea anethifolia).
This has been a dry spring with fewer flowers than normal. 

Area 3 River.
The river area consists of the Hotham River, associated dry channels and fringing vegetation. The fringing vegetation is very weedy with lots of introduced grasses and Bridal Creeper. The old dam is about 450 metres west of the point where the track ends. LIttle remains apart from a line of posts, and to reach it is a scramble through uneven weedy land unless the river is dry and one can walk along the river bed.
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The dam and it's history is contained in this blog.

Area 4. This is a narrow strip of land containing a drain going between the highway and Power Street to the river. Lots of green spider orchids and flowering shrubs in September.

The devastating 2022 wildfire, which started near North Yiiliminning Nature Reserve has had an interesting consequence. In spring 2023 I discovered two very showy  native plants in burnt areas, which had not been recorded in the area.
Alyogyne huegelii and Solanum symonii are both recorded in Florabase as mainly coastal species.
How can this be?
In my opinion it is a by product of plant type, soil type, fragmented natural vegetation and changed fire management.

• Both species are fire ephemerals, which only live for 6  to 8 years, and need fire for seed to germinate.
• Both occur here on sloping heavy red soil from mafic (dolerite) rocks, which usually occurs as lines from cracks in basement granite rock. These soils are less common in our reserves, because they are good farming soils.
• Scattered wheatbelt reserves are not actively managed. Ockley and Birdwhistle reserves had not been burnt for decades

Alyogyne huegelii (Wheatbelt Hibiscus) is presently a dense understorey on a mafic loam slope in Ockley Nature Reserve. I clearly recall visiting this spot before the fire and taking a photo, which I later deleted because it was an unattractive view of scattered mallees on bark strewn ground with almost no understorey. It is now a dense mass of Alyogyne and other shrubs - Oh I wish I had kept that before fire image!

I also found several flowering Goodenia etheira plants on lateritic sand soil at Ockley Nature Reserve. This downy small flowered plant is only recorded further north in the Central Wheatbelt. I wonder how many other 'new discoveries' may be in the burnt area?

On light textured soils the main fire ephemerals have been Gyrostemon subnudis and Kennedia prostrata, which have emerged in profusion at Birdwhistle Rock.

The name 'Velvet Bush' comes from a dense cover of short hairs on foliage and flowers.  They are commonly called paper flowers because of the papery sepals surrounding the small flowers.
Characteristics are

• Small to medium shrubs.
• Flowers and foliage are generally covered with stellate (star shaped) hairs, which can give them a furry or prickly appearance.
• Mostly pink/purple flowers composed of coloured sepals; (petals are tiny or absent.)
•  Flowers lack nectar, and are  buzz pollinated by generalist native bees, which feed on pollen released from stamens that form a column surrounding the style. 
• Dry fruit, which release seeds.

​Orriginally in the Sterculariaceae family, they have been amalgamated with other former families by taxonomists into a large Malvaceae family using genetic analysis. As an amateur I am confused. Florabase, has dual identification for these genera.
Top of page -Malvaceae / genus (Thomasia, Guichenotia, Lasiopetalum) 
Below  Family Sterculariaceae (Subfamily Byttnerioideae), Tribe Lasiopetalae.

​To the average person Thomasia and Guichenotia species are very similar. 
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Thomasia
​The most common species in this area are Thomasia foliosa and Thomasia macrocalyx. They both have small pink flowers composed of sepals with a single midrib, which are joined about halfway up to form a corolla tube. Although not showy, the flowers have a delicate interior.  They flower in June-July.

Thomasia macrocalyx is a tough hairy shrub with 1cm flowers, which I see in granite or dolerite rock soil. There are no petals, only pink sepals surrounded by green bracts. The smooth ovary is enclosed by large longish dark heart-shaped stamens, which open at the top. When native bees fold over the flower tip and buzz their wings, powdery pollen is sucked up through pores at the end of the stamens and lodge into the bee's body hair, and the flower stigma is fertilised by pollen on the bee from other flowers.

Guichenotia have have narrower leaves and several ribs in the calyx, but the difference is subtle. Luckily the two species in the Narrogin area, G. macrantha and G. micrantha which occur on sandier soils are very similar. The exterior of the sepals have  dark coloured hairs, which show up as a star shape when taking an photo of the flower with the sun behind it. Makes a great image.

Lasiopetalum
Thid genus can easily be distinguished from Thomasia and Guichenotia by the sepals, which lacks ribs and are split almost down to the base. I found Lasiopetalum microcardium at Harrismith Nature Reserve.

Now a few Red Herrings
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Cyanostegia lanceolata is in the Malvaceae family, but has both petals and sepals and isn't hairy. But they do have light patterned , light coloured sepals, when the ring of dark purple petals  I have also been fooled by the petals, particularly when they are folded as being dark Malvaceae anthers. 
It flowers in September on gravelly soil and has stunning flowers, which glow from a distance with the sun behind them.  

Halgania anagalloides in the Boraginaceae family also has small  flowers with a calyx, blue petals, and a protruding ring of buzz pollinated anthers, which is also shared with Solanaceae (tomato) flowers. it is smallish shrub.

More information on identication
Seednotes 

My interest in ochre was rekindled recently, when I explored the Claypit Nature Reserve near Wickepin. Years ago as part of a mining lease there, the side of a mesa was excavated to get adjoining white and red ochre clays for brickmaking. The white section formed over granite, and red over a dolerite dyke.

​The importance of ochre for first nations people is summarised in this article on the ancient Weld Ranges Ochre mine.

An ochre pit at Dryandra National Park is one of over 440 recorded around Australia. For a nation this large, it is a small number, hence the value of ochre as an item of trade.

A good local example is the Uellelling Hill kaolinite mine east of Wickepin. The image below of a cutting in the exploration phase displays typical layers of an old laterite profile.

• ​The gravel layer contains most of the plant roots.
• The mottled zone layer is a transition to the pallid zone layer, which is stained by iron leaking down from the gravel layer.
• The pallid zone layer is decomposed bedrock, which has been weathered to clay and sand, and infilled with extra clay 

​The clay is a type of kaolinite called halloysite, which has many uses ranging from fine porcelain, paint additive, medicine and dentistry. Unlike other clays halloysite consists of microtubes rather than sheets.
​Electron microscope images of halloysite forming around bacteria lead on to a great story of soil development where plants lift minerals up from the depth in soil water, and microbes and fungi convert them to lateritic gravels, bauxite or clays.

​Pallid zone clay is also packed with salt, which was uplifted with soil water by native trees. When land was cleared, this salt washed down into rising groundwater and created our severe wheatbelt salinity problem.

White dams dotted around our landscape show the widely distributed pallid clay. If early Noongars had bulldozers, ochre would have been easy to get!
However, ochre only outcrops naturally on breakaway slopes. Granitic breakaways contain white ochre and less commonly yellow ochre (which contains an iron oxide called limonite). Red ochre contains an iron oxide called haematite which is mostly found on steep red-brown breakaways, which have formed off very iron-rich rocks such as dolerite.  Green ochre (containing a nickel oxide) is rare, only being found on ultramafic rock breakaway areas such as the Goldfields.
Good ochre contains very little sand.

​To see a jaw dropping breakaway, visit Buckley's Breakaway 70km east of Kulin

I found an easy way to make good ochre.

• Put the ochre sample in a bucket and add enough water to make liquid
• Swirl the liquid vigourously, then pour clay and water slurry off into another bucket leaving sand behind
• Leave the water and clay for a couple of days until the clay settles out leaving water above. Adding salt may help.
• Pour off the water leaving the clay slurry behind to evaporate to a creamy consistency

I take some samples in jars when I talk to visitors. The kids love it and as shown by the Foxyochrefoot image, even some adults indulge. it washes off easily. 

Further reading

• ​Ochre is of the Earth
• Exploring the biological dimension to pedogenesis with emphasis of the ecosoystems, soils and landscapes of southwestern Australia W. Verboom and J.F. Pate
• Why are plants and soils in the Narrogin area so diverse?

The 45 hectare Claypit Nature Reserve  is 33 kilometres east of Narrogin and 7 kilometres west of Wickepin. The reserve appears to be much larger because it surrounds a 5 hectare water reserve, and is surrounded by extensive uncleared land on private properties. The reserve is fenced on east, west and southern sides, but the fence on the west includes a wedge of private bushland in pristine condition. There is no boundary fence on the northern side. Most of the bush is in excellent condition, with relatively few weeds. The entry road splits into a continuing but rougher direct approach, and a more pleasant loop on the left. There are no facilities. Excellent bird watching location.

​​The reserve is a remnant of an ancient undulating upland plain, which separates the Avon and Hotham River catchments.
The multi-million year old plain can be likened to a layer-cake, with a top layer of gravel, sand, or ironstone overlying a pale/mottled/red clay (pallid zone) over decomposing granite or dolerite bedrock. Pallid zone is basically kaolinite clay and quartz grains. A very pure deposit is being mined at Uelelling Hill. It is also the clay in ochres.
A sign adjacent to the Narrogin Kondinin Road is a trifle misleading in associating the reserve with the mafic Binneringie Dyke, which is some kilometres further south. Underlying rock here is mainly granite with a few  intruding dolerite dykes. White granite kaolinite intruded by narrow red kaolinite seams from dolerite dykes can be seen on sides of cuttings as you drive to the water tank.

The ancient plain remnants are gravelly mesas, which are mostly bounded by steep-sided breakaways. Gravelly soil on the mesas has  wildflower-rich often Proteaceae shrubland, which interspersed by wandoo, rock sheoak, and brown mallet woodland.
Hard setting loam and clay soils from the pallid/pink zone on breakaway slopes and upland surroundings downslope are mostly dominated by  Brown Mallet woodland.
 Open Wandoo woodland and more dense Rock Sheoak thickets in and around granite outcrops have more fertile soils formed from basement rock.
​Much of the reserve is fairly easy walking country  but there are no signposted walk trails and people with a poor sense of direction may get lost.

I suggest a visit to the following two areas.

1. WICKEPIN WATER WATER TANK
​Park next to the water tank.

The tank has a capacity of 9 million litres, which is pumped through a pipe from the  Harris River Dam near Collie. Constructed in 1964, the tank is part of a water network that is very important to the district. before this, salinity of land and water sources,which began in the early 1900's caused severe fresh water shortages for people and livestock. Before scheme water, Wickepin residents were dependant on local wells and in desperate circumstances, water from the Wickepin Railway Dam.

​Two informal trails provide access to diverse and wildflower-rich country.
A track winding downhill around the water tank  to a granite outcrop features a range of spring wildflowers. Note impressive Tangled Grevillea clumps. The granite outcrop is on the northern boundary of the reserve. Please avoid treading on delicate lichens in and around the rock.
​Surrounding rocky bushland is choked with dead vegetation and can be difficult to walk through.

An easy walking informal track leads to the breakaway. This is pleasant gravel wildflower country. if you look carefully in land to the west, you may be lucky enough to see some Cowslip/Little PInk Fairy Orchid hybrids. Please leave them intact?- they are precious and uncommon.

2. CLAYPIT
The bare area was an old mining lease to excavate clay for house bricks produced in Narrogin. The red clay overlies a 30 metre wide east-west dolerite dyke, and white from relatively low quartz granite, are also sources of ochre. I collected and made my own red, orange and white ochre from here!
An informal dead-end track on the western side is an easy walk to the west with a breakaway on the left (south) side. The area is pleasant open bushland with some shrub understorey.