Flora and vegetation of banded iron formations of the
Yilgarn Craton: Koolanooka and Perenjori Hills
RACHEL MEISSNER AND YVETTE CARUSO
Science Division, Department of Environment and Conservation, PO Box 51,
Wanneroo, Western Australia, 6946. Email: Rachel.Meissner@dec.wa.gov.au
A study of the flora and plant communities of Koolanooka and Perenjori Hills, east of Morawa, recorded 238 taxa,
with 217 native and 21 weeds. Nine priority taxa were found and five new species were identified and are considered
endemic to the hills. Fifty quadrats were established to cover the major geographical, geomorphologic and floristic
variation across the hills. Data from 48 of these quadrats were used to define five community types, with two
subtypes in one community. Differences in communities were strongly correlated with landform and soil fertility.
Patterns of high plant endemicity and restricted communities are similar to those found on other ranges within the
Yilgarn Craton. None of the plant communities found on the Koolanooka and Perenjori Hills is reserved in the
Banded iron formation ranges within the Yilgarn Craton
are highly prospective for iron ore exploration and mining.
Previous studies on greenstone and banded ironstone
ranges in the Goldfields have found high plant endemicity
and restricted vegetation types (Gibson et al. 1997; Gibson
& Lyons 1998a,b; Gibson & Lyons 2001a,b; Gibson
2004a,b). It is hypothesised that similar patterns would
also be found on the ironstone ranges in the Yilgarn
Craton. The current knowledge of the vegetation and flora
that occur on these ranges is poor and based on Beard’s
pioneering vegetation mapping (Beard 1976).
The Koolanooka Hills, Aboriginal for hill of wild
turkeys (Rogers 1996), is located approximately 20 km
east of Morawa. Perenjori Hills is located 10 km southeast
of Koolanooka and 12 km to the northeast of Perenjori
(Figure 1). Both hills are located near the boundary of
the agricultural and pastoral zones in Western Australia,
which roughly correlates with the boundary of the
Eremaean and Southwest IBRA provences (Figure1).
The Koolanooka and Perenjori Hills are part of the
Koolanooka synform, one of several Archaen belts within
the Yilgarn Craton. The hills strike NNW–SSE and N–S
respectively. The banded iron formation within the
Koolanooka synform is part of the middle sedimentary
association. The association contains siltstones, sandstones,
conglomerates interbedded with banded iron formation and
shale. This in turn is intruded by granitoids and bounded
by upper and lower volcanic associations (Baxter & Lipple
1985). Historically, iron ore was mined in the northern
part of Koolanooka Hills between 1966 and 1975 (Baxter
& Lipple 1985). Currently, there is interest in further
exploiting the iron ore resources of Koolanooka Hills.
The climate of the region is dry warm mediterranean
(Beard 1990) with a mild wet winters and hot dry
summers. Mean annual rainfall recorded at Morawa is
333.8 mm, but not as variable in more arid regions (227.8
decile; 453.7 mm 9
decile; recorded 1911 to
cold fronts moving in an easterly direction over the Indian
Ocean. Summer rains are unpredictable and tend to occur
later in the season. Summer rains originate from troughs
and depressions and sometimes tropical cyclones off the
northwest coast of Western Australia (Rogers 1996).
The highest maximum temperatures occur during
summer, with the January as hottest month (mean
maximum temperature 36.7 °C with mean of 7.4 days above
40 °C). Winters are mild with lowest mean maximum
temperatures recorded for July of 18.1 °C. Temperatures
rarely fall below 0 °C in winter (a mean of 0.2 days below
0 °C), with a mean minimum of 6.2 °C in July.
The Koolanooka and Perenjori Hills were described
by Beard (1976) as a single vegetation system, the
Koolanooka system, consisting of Allocasuarina
Koolanooka vegetation system was endorsed by the
Minister for Environment as a Threatened Ecological
Community (TEC) in 2001. The TEC, plant assemblages
of the Koolanooka system, is based upon Beard’s (1976)
vegetation system described above, covering the entire
extent of both hills, approximately 4500ha. It is currently
ranked vulnerable following English and Blythe (1999).
R. Meissner & Y. Caruso
ᮡ) on Koolanooka and Perenjori Hills. The 340 m contour is shown,
The aim of the present work was to undertake a
detailed floristic survey of the Koolanooka and Perenjori
Hills and to identify the plant communities that occur on
the ranges. This was achieved by detailed flora lists, and
description of plant communities based on a series of
permanently established quadrats. Ultimately, the aim is
to place these communities in a regional context with other
banded ironstone ranges throughout the Yilgarn Craton.
Fifty 20 x 20 m quadrats were established on the crests,
slopes and foot slopes of Koolanooka and Perenjori Hills
in October 2005 (Figure 1). These quadrats were
established to cover the major geographical,
geomorphologic and floristic variation found in the study
area. Each quadrat was permanently marked with four steel
fence droppers and their positions determined using a GPS
unit. All vascular plants within the quadrat were recorded
and collected for later identification at the Western
Data on topographical position, disturbance,
abundance, size and shape of coarse fragments on the
surface, the amount of exposed bedrock, cover of leaf litter
and bare ground were recorded following McDonald et
al. (1990). Additionally, growth form, height and cover
were recorded for dominant taxa in each stratum (tallest,
mid- and lower).
Twenty soil samples were collected from the upper 10
cm of the soil profile within each quadrat. The soil was
bulked and the 2 mm fraction analysed for B, Ca, Cd, Co,
Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, S and Zn using
the Mehlich No. 3 procedure (Mehlich 1984). The
extracted samples were then analysed using Inductively
Coupled Plasma – Atomic Emission Spectrometer (ICP-
AES). This procedure is an effective and cost efficient
alternative to traditional methods for evaluating soil
fertility and has been calibrated for Western Australian
soils (Walton & Allen 2004). pH was measured in 0.01M
at soil to solution ratio of 1:5. Effective cation
exchange capacity (eCEC) was calculated from the sum
of exchangeable Ca, Mg, Na and K (Rengasamy &
Churchman 1999). Exchangeable Ca, Mg, Na and K were
obtained by multiplying the values of Ca, Mg, Na and K
obtained from ICP-AES by a standard constant.
Quadrats were classified on the basis of similarity in
species composition on perennial species only, to be
consistent with other analyses of banded ironstone ranges
(Gibson 2004 a, b). Perennials were also more consistent
across season and amount of pre-survey rainfall. Life form
followed Paczknowska and Chapman (2000), where
perennial is defined as a plant whose life span extends over
2 or more growing seasons. The quadrat and species
classifications were undertaken using the Bray and Curtis
coefficient and Flexible UPGMA (Unweighted pair-group
mean average; â = -0.1; Belbin 1989). Indicator species
and species assemblages characterising each community
were determined following Dufrene and Legendre (1997)
using the INDVAL routine in PC-ORD (McCune &
Mefford 1999). Quadrats were ordinated using SSH
(semi-strong hybrid multidimensional scaling),
correlations of environmental variables were determined
using the PCC (Principal Component Correlation) routine
and significance determined by the MCAO (monte-carlo
attributes in ordination) permutation test in PATN (Belbin
tested using Kruskall-Wallis non parametric analysis of
variance (Siegel 1956), followed by non-parametric
comparison (Zar 1999). Correlations between
environmental parameters were analysed using Spearman
Rank correlation coefficient.
Nomenclature generally follows Paczkowska and
A total of 237 taxa from 53 families were recorded from
the 50 established quadrats and adjacent areas. Of these
237 taxa, 216 were native and 21 weeds. The dominant
families in order were Asteraceae (39 species, 3 weeds),
Myrtaceae (21), Poaceae (21 species, 11 weeds),
Mimosaceae (19) and Chenopodiaceae (11).
Rare and Priority Flora
Nine priority taxa (designated P1, P2, P3) were found
during the survey of Koolanooka and Perenjori Hills.
• Acacia acanthoclada subsp. glaucescens (P3) is an
intricately branched shrub to 2 m with pungent
branchlets and glaucous phyllodes. It was found
growing in open forests and mallee woodlands and
of E. ebbanoensis or E. loxophleba subsp. supralaevis.
It has been previously found on Koolanooka Hills.
• Baeckea sp. Perenjori (J.W. Green 1516) (P2) is a
small myrtaceous shrub to 1.5 m with pink flowers.
This taxon is restricted to the Morawa and Perenjori
region. In this survey, it was found growing on the
crests and slopes of Perenjori and Koolanooka Hills.
• Gunniopsis rubra (P3) is a small succulent herb to
10 cm growing on water gaining sites in sandy loam.
A single collection was made of this taxon from a
colluvial outwash site, growing under mallee
woodlands of Eucalyptus subangusta subsp. pusilla and
Eucalyptus ebbanoensis subsp. ebbanoensis.
• Melaleuca barlowii (P1) is a myrtaceous shrub to
1.8 m known mainly from the Mullewa and Morawa
area growing on roadside reserves. It has been
collected previously from Koolanooka Hills. In this
survey, it was collected from two sites on Koolanooka
Hills, growing in shrublands of Allocasuarina
acutivalvis on a lower and mid slope.
• Millotia dimorpha (P1) is a small yellow flowered
daisy characteristically with two rows of glandular
involucral bracts. This species is poorly collected, and
originally known only from Koolanooka Hills and
Kadji Kadji Station. It has recently been found
growing on the slopes of Mount Karara, east of Kadji
Kadji (Markey and Dillon, 2008).
• Mribelia sp. Helena and Aurora (B.J. Lepschi 2003)
(P3) is a perennial, leaf less but pungent shrub to
3m. Originally found only on the Helena and Aurora
Ranges in the western Goldfields, it was found
growing on the mid to upper slopes of Koolanooka
Hills with A. acutivalvis and E. ebbanoensis. This is a
new record for Koolanooka Hills and a range
extension of over 400km for the species.
• Persoonia pentasticha (P2) is a proteaceous shrub to
2 m with pungent five ribbed leaves. In this survey,
it was found at two sites on crests of Koolanooka
Hills, growing in open forests of A. acutivalvis and
• Rhodanthe collina (P1) is an annual daisy with small
delicate flowers. It is known mainly from the pastoral
stations near Paynes Find on flats and water gaining
sites. A single specimen was found on Koolanooka
Hills on a rocky midslope. This is a new record, range
extension and population for the area.
• Stenanthemum poicilum (P2) is small shrub to 50 cm
that was found growing on the crests and upper slopes
of Koolanooka Hills in open mallee forests and
woodlands of E. ebbanoensis and A. acutivalvis. It has
been previously collected from rocky sites in the
Morawa area. This a new record for Koolanooka
During the survey, six new species were identified. These
taxa are apparently endemic to the Koolanooka and
Perenjori Hills. Further surveys are required to determine
the distribution and population size of each taxon. Further
taxonomic work is also required to determine taxonomic
rank of several of the taxa.
• Acacia muriculata is a shrub to 2 m found growing
only on the slopes and crests of Koolanooka Hills in
open mallee forests and woodlands of E. ebbanoensis
and A. acutivalvis. It characterised by hair y
verruculose-ribbed branchlets and falcate phyllodes
with solitary globular flowers (Maslin & Buscomb
2007). It has recently been listed as Priority One
species and is known only from Koolanooka Hills.
• Acacia graciliformis is an openly branched shrub to
2 m with slender stems and short pungent phyllodes.
It was found at four sites growing in Eucalyptus
woodlands crests and slopes of Koolanooka Hills.
This species is closely allied to Acacia mackeyana and
A. dissona which differ significantly from the species
in their phyllode nervature (Maslin & Buscomb
2007). It has been listed as a Priority One species
due to its restricted habitat and location.
• Caesia sp. Koolanooka Hills (R.Meissner & Y.Caruso
78) is a geophyte to 30 cm with pale yellow flowers
growing on crests and slopes of Koolanooka and
Perenjori Hills. The species is closely related to Caesia
sp. Wongan (K.F. Kenneally 8820) but with smaller,
pallid flowers and spreading anthers. It may belong
to a sub-group of the genus that is endemic to
ironstone ranges, including such species as Caesia
sp. Ennuin (N.Gibson & M.N.L yons 2737)
, pers. comm.). The occurrence on the
clay soils on flats and plains.
• Dodonaea scurra is a dioecious shrub to 1 m with
verticillate leaves and solitary flowers. It is closely
allied to Dodonaea caespitosa but is distinguished by
relatively more clustered leaves per node and distinctly
rounded capsules with simple scattered hairs
(Shepherd et al. 2007). It was found only on the
slopes and crests of Koolanooka Hills in several
different communities. There was one previous
collection in the Western Australian Herbarium of
this taxon, which was misidentified, from the
Koolanooka Hills. It is has recently been listed as
Priority One due to its limited distribution to
• Drummondita rubroviridis is a spindly shrub to 1.5 m
with glandular clavate leaves, held recurved to
horizontal, and subsessile, solitary flowers that possess
red petals with green tips (Meissner & Markey 2007).
It is closely related to D. wilsonii and D. ericoides,
both taxa with restricted distributions (Mollemans
1993). This species was only found on the slopes
and crests of Koolanooka Hills, growing mainly in
open mallee forests and woodlands of E. ebbanoensis
and A. acutivalvis.
• Lepidosperma sp. Koolanooka (K. Newbey 9336)
is a sedge to 50 cm found growing on the slopes
of Koolanooka and Perenjori Hills in open forests
and shrublands of A. acutivalvis or A. campestris.
Although previously collected from Koolanooka,
it was not recognised as a new species until the
current survey collected sufficient material for the
status to be determined with confidence. It is
closely related to another newly discovered granite
endemic, Lepidosperma sp. Karara (H.Pringle
3865) found growing on granite outcrops on
Flora of taxonomic interest
• Hibbertia aff. exasperata belongs to a complex,
including Hibbertia rostellata, Hibbertia nutans and
Hibber tia uncinata, of unresolved taxonomy
(Wheeler 2004). Fur ther work needs to be
undertaken to elucidate the taxonomic relationships
within this complex. The species was collected only
from the slopes and crests of Koolanooka Hills,
mainly from mallee woodlands of E. ebbanoensis and
• Eucalyptus ebbanoensis subsp. glauciramula is a mallee
to 3 to 6m and was collected from both ranges. It
was commonly the dominant Eucalyptus and was
found across the landscape, from crests to lower
slopes and plains. It has previously been collected
from the range. The nearest populations are nearly
400 km to the east in the Goldfields.
• Labichea lanceolata subsp. brevifolia is a shrub to 3m.
It was found growing at single site on a midlsope of
Koolanooka Hills, in an open forest of A. acutivalvis.
The taxon is found in three discreet areas; around
Esperance, York and an outlying nor thern
population. The specimen collected in this survey
belongs to the northern variant of the taxon, found
in scattered populations between Geraldton and
Morawa. These collections have narrow leaves and
look superficially more like Labichea eremaea than
4 rather than 5 sepals. Revision of this taxon is
• Tetraria aff. capillaris is a sedge with curly leaves
growing to 50 cm. It was found growing at a single
site on Koolanooka Hills in Allocasuarina acutivalvis
subsp. acutivalvis woodland with M. nematophylla,
H. aff. exasperata and L. sp. Koolanooka (K.Newbey
9336). It is closely allied to Tetraria capillaris and
this complex is in need of taxonomic revision
, pers. comm.).
Science Division, Department of Environment and Conservation, Western Australia
Science Directorate, Botanic Gardens & Parks Authority, Kings Park and Botanic Garden, Western Australia
Initial analysis of the data with all species excluding
singletons (species which occurred in only one plot)
compared to an analysis of data with only perennial species
revealed little difference in the groupings and ordination.
Ninety eight perennial taxa were included in the final
analysis. Subspecies of E. ebbanoensis and A. acutivalvis
were reduced to species level for the analysis, due to the
difficulty in differentiating between subspecies without
sufficient flowering or fruiting material.
Forty eight quadrats out of the fifty established on the
ranges were used in the final analysis. In the initial analysis,
two quadrats were outliers and subsequent removal
improved the ordination stress. Quadrat KOOL26 was a
species poor Eucalyptus salmonophloia woodland occurring
over limestone and KOOL36 was an open shrubland of
had a high percentage of weeds present, probably due to
high levels of disturbance. Both sites had high levels of
calcium, magnesium and high pH.
Community groups were separated into 5 groups,
based upon clear pattern in the final dendrogram. This
pattern was also the first division separates the
Allocasuarina shrublands and thickets (Communities 1-4)
from the more fertile woodland sites (Community 5;
Figure 2). The second division separates communities
restricted mainly to the crests, upper and mid slopes of
Koolanooka Hills (Communities 1 and 2) from
communities common between Perenjori and Koolanooka
Hills (Community 3) and communities found on the lower
slopes of Koolanooka (Community 4). These divisions
can also be clearly seen in the sorted two-way table of the
sites and species classification (Table 1).
In total, five community types, one with two subtypes,
Community 1 – Woodlands, mallee shrublands and
shr ublands of A. acutivalvis, E. ebbanoensis over
shrublands of Acacia spp. and Myrtaceae spp. The
community occurs only on crests and slopes of Koolanooka
Hills and can be further divided into 2 subtypes.
Community type 1a – This community is found only on
Koolanooka Hills on all landforms except colluvial
outwashes. It is described as mallee shrublands, shrublands
and woodlands of A. acutivalvis, E. ebbanoensis and
Melaleuca spp. over shrublands with Micromyrtus
racemosa, G. paradoxa and M. sp. Helena and Aurora (B.J.
Lepschi 2003) present. The community had the lowest
mean species richness ( annuals and perennials) of all
communities (mean 32.3 ± 0.6 species per quadrat). The
best indicator species are Acacia neurophylla subsp.
neurophylla, Cheiranthera filifolia var. simplicifolia,
D. rubroviridis, E. ebbanoensis, G. paradoxa, Micromyrtus
racemosa subsp. racemosa, Melaleuca atroviridis, M. sp.
Helena and Aurora (B.J. Lepschi 2003) and Thysanotus
Community type 1b – This community is only found on
the slopes of Koolanooka Hills. It is best described as
woodlands and shrublands of A. acutivalvis with an
understorey of L. sp. Koolanooka (K.Newbey 9336),
Pimelea avonensis, and Acacia nigripilosa subsp.
nigripilosa. Mean species richness was 34.0 ± 0.5 species
per quadrat. Indicator species were A. nigripilosa subsp.
Hills (R.Meissner & Y.Caruso 78), L. sp. Koolanooka (K.
Newbey 9336), M. nematophylla, P. avonensis and
Tricoryne elatior. This community is characterised by taxa
from Species groups D and G (Table 1).
Community type 2 – This community occurs only on
Koolanooka Hills, mainly on crests and upper slopes and
contains taxa from Species group A (Table 1). It can be
described as mallee woodlands and shrublands of
second highest species richness with a mean of 38.6 ± 1.3
species per quadrat. Indicator species were S. poicilum,
H. aff. exasperata, A. acutivalvis and Ptilotus obovatus
Community type 3 – This community occurs on midslopes
and crests of Koolanooka and Perenjori Hills. It can be
described as open woodlands, shrublands and open
shrublands of Allocasuarina spp., M. nematophylla, and