Chemistry and medicinal properties

There has been very limited investigation of the chemical properties of Lepidosperma tissues. Aplin and Cannon (1971) assessed three Western Australian Lepidosperma species and found that they lacked alkaloids. Kükkonen (1971) identified six different flavonoid compounds in L. concavum but did not identify the individual compounds present. Williams and Harborne (1977) conducted a survey of flavonoid chemistry in Cyperaceae and found that L. tortuosum contained quercetin. In further studies, Harborne et al. (1985) surveyed 16 Lepidosperma species for the presence of flavonoids and found that flavonols were common in Lepidosperma species and included some yellow aurone pigments and an anthocyanin-type pigment, carexidin. Harborne et al. (1985) considered that Lepidosperma can be well characterized chemically by the presence of tricin, quercetin and isorhamnetin, while mostly lacking luteolin and aurones, the latter being present rarely in some species. Pigmentation can play an important role in photoprotection, a factor especially important in species occupying xeric environments (Steyn et al., 2002). Flavonoids play particular roles in plant defence, often deterring herbivores from feeding on the plants (Simmonds, 2001; Morimoto and Komai, 2006). The presence of two potentially allelopathic chemicals (cyperotundone and α-cyperone) has been explored in Cyperus rotundus by Morimoto and Komai (2005) but it is unknown whether these chemicals are more widespread in the Cyperaceae and whether they might be found in Lepidosperma species.

Naturally derived pharmaceutical products remain the primary source of new medicinal drugs and analysis of new plant-derived compounds remains an important part of modern medical research (Newman et al., 2008). Gott (1993) reported the traditional use of the stem bases of L. gladiatum and L. viscidum for use against colds by Aboriginal people in South Australia. This has been investigated by Semple et al. (1998) and Palombo and Semple (2001) who investigated the antibacterial properties of these species, finding that extracts of L. gladiatum and L. viscidum were both active against a range of Gram-positive bacteria. Palombo and Semple (2002) conducted further tests with the most active species, L. viscidum, and found activity against methicillin-resistant Staphylococcus aureus (MRSA) and partial activity against vancomycin-resistant Enterococcus (VRE). Meilak and Palombo (2008) investigated L. viscidum for potential activity against Mycobacterium fortuitum and M. smegmatis but no significant effect was found. A significant amount of work has been undertaken to isolate stilbenes, including chemical analogues of resveratrol, from Scleria holoschoenus (Abdel-Mogib et al., 2001) and a number of Carex species (see González-Sarrías et al., 2011). Resveratrol is a well-known constituent of red wine that has shown benefits in reducing the risk of heart disease and possesses anti-cancer and anti-ageing properties (González-Sarrías et al., 2011). Recently, novel stilbenes have also been isolated from a Lepidosperma species in South Australia and their potential medical benefits are the subject of ongoing research (Duke et al., 2012).

Nutrient acquisition

Cyperaceae are recognized for their ability to colonize a diverse range of habitats. Their prevalence in dry shrublands and woodlands in Australia may in part be explained by their ability to extract phosphorus from nutrient-poor soils. Cluster roots were first described in Cyperaceae by Renner (1935). The production of these specialized root structures in Carex is documented by Selivanov and Utemova (1969) who confused them for mycorrhizal structures. Lamont (1974, 1981, 1982, 1983, 1984) further defined the root type as ‘dauciform roots’ and characterized their ability to enhance nutrient uptake in Cyathochaeta, Gahnia, Lepidosperma and Schoenus. More recent work has shown that many genera and species in Cyperaceae tribes Schoeneae (including Lepidosperma) and Cariceae have the ability to develop such dauciform roots and they may be present in all species in the tribe Schoeneae (Raab et al., 1999; Shane and Lambers, 2005; Shane et al., 2005; Yano et al., 2011).

The dauciform roots of Lepidosperma are among the largest produced in the Cyperaceae (Lambers et al., 2006; Fig. 4). Production of dauciform roots in Lepidosperma is induced by low availability of phosphorus and results in the production of elongated cells that release carboxylates in an exudative burst (Shane et al., 2006). Carboxylates promote the release of soil-bound phosphorus (Shane et al., 2005; Watt and Weston, 2009). The full range of conditions is yet to be determined (Miller, 2005; Shane et al., 2005; Playsted et al., 2006) and Bakker et al. (2005) found that the addition of phosphorus did not influence the production of dauciform roots in Schoenus nigricans.

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Fig. 4.

Dauciform roots of Lepidosperma longitudinale (western form), from Bold Park, Western Australia (photos: Mike Shane).

In addition to dauciform roots, some Lepidosperma species also commonly develop sand-binding roots that can serve to stabilize surrounding soil and aid water uptake and retention (Dodd et al., 1984). The ecological role of these sand binding roots has been explored in detail for the morphologically similar Lyginia barbata (Anarthriaceae; Shane et al., 2009, 2010, 2011). Similar studies should be undertaken in Lepidosperma and allied genera.

While studying the natural abundance of nitrogen in Banksia woodland ecosystems, Lepidosperma sp. Coastal Dunes was shown to have a relatively low level of shoot nitrate reductase (about 40 pkat. per g f. wt) and corresponding low δ¹⁵N (about 1; Pate et al., 1993; Pate, 1994; as L. angustatum). Nitrate is an important macronutrient and plays a vital role in growth (Crawford and Glass, 1998). The low level of shoot nitrate reductase found by Pate et al. (1993) may indicate that Lepidosperma species preferentially use organic nitrogen as found for the Arctic sedge Eriophorum vaginatum by Chapin et al. (1993).

Bowman et al. (1986) studied mineral and nutrient uptake and mobilization by plants across a landscape in south-western Tasmania, finding that L. filiforme had foliar concentrations of 113 µg g⁻¹ phosphorus, 4100 µg g⁻¹ potassium, 950 µg g⁻¹ sodium, 950 µg g⁻¹ calcium and 540 µg g⁻¹ magnesium. This species was able to withdraw 93 % of phosphorus and potassium, 58 % of sodium and 18 % magnesium prior to leaf senescence. Such a high level of internal nutrient recycling means that Lepidosperma species are well adapted to survival in low-nutrient soils.

Studies by Jones (1968) suggested that the addition of fertilizer to natural stands of L. sieberi (as L. concavum) had no significant impact on growth rate over two years. However, results of studies on the effect of overstorey thinning and fertilization for L. urophurum suggest that many respond positively to the addition of fertilizer (Bauhus et al., 2001). Bridle and Kirkpatrick (2003) investigated the impacts of human and animal waste on plant growth and found that the addition of urine increased the cover of L. sieberi (as L. concavum).

Ultramafic/serpentine substrates

Serpentine soils are derived from ultramafic parent rock. They are defined by the presence of extreme mineral concentrations, commonly low calcium, phosphorus and potassium, and high magnesium and nickel (Nagy and Proctor, 1997). Plants occurring on these ultramafic/serpentine substrates often have specific adaptive strategies to deal with mineral toxicity and nutrient deprivation (Nagy and Proctor, 1997; Proctor, 2003). Relatively little is known about floristic communities on ultramafic soils in Australia, despite the presence of a number of species endemic to these communities (Gibson et al., 1992). There is considerable interest in the flora of ultramafic soils in southern Western Australia, particularly on Bandalup Hill, near Ravensthorpe. This hill and the associated Ravensthorpe Range show very high levels of floristic diversity with a high level of local endemism and rarity (Kern et al., 2008). A detailed assessment of Lepidosperma taxa from the Ravensthorpe Range and Bandalup Hill showed that 42 species should be recognized from this area, only five of which are currently named (Barrett et al., 2009). About half of these taxa are locally endemic and 18 of these require conservation assessments to determine whether they should be listed as rare or threatened (Barrett et al., 2009). This geographical region has by far the highest diversity for the genus Lepidosperma, and also has a large number of species in genera such as Eucalyptus and Melaleuca (Kern et al., 2008). The Ravensthorpe Range has a very diverse and complex geological history and this is thought to be one of the reasons for the range's high levels of floristic diversity. Kruckeburg (1986) has suggested that unusual geologies may often act as opportunities for speciation as plants adapt to particular substrates and become unfit outside their particular niche. Speciation across geological boundaries may occur even with continued outcrossing if the out-crossed progeny from the alternative geological parent fail to survive. As a result, a number of closely related species may be found in unusually close proximity in geologically diverse locations (Heslop-Harrison, 1964).

An unidentified Lepidosperma species from south-east Queensland was found to grow effectively in metal-rich soils, absorbing significant amounts of copper and arsenic, and some silver, cadmium, molybdenum, lead and zinc (Ashley et al., 2003). Lepidosperma australe has been recorded as a significant gold-accumulating species in New Zealand where it may have potential as an indicator species for gold prospecting (Ward and Brooks, 1978).

Lepidosperma laterale and L. perteres are locally common in ultrabasic massifs of New Caledonia (Jaffré, 1974). Within New Caledonia, L. pauperum and L. perplanum are both restricted to ultrabasic soils, while L. perteres is not restricted to specific soil types (Morat et al., 1986). Nutrient acquisition varies with soil type, with Jaffré (1976) demonstrating that L. perteres is able to take up significantly higher amounts of nitrogen and potassium from ferrous soils than from brown soils in New Caledonia. The uptake of manganese from ferrous soils was ten-fold greater than that from brown soils while uptake of magnesium from ferrous soils was significantly reduced. There was also a ten-fold reduction in the uptake of silicon from ferrous soils (Jaffré, 1976).

Fire and disturbance response

Long-term survival in ecosystems prone to disturbance or environmental fluctuations is primarily determined by the ability to persist and reproduce. Plants that have the ability to resprout following disturbance events such as fire or grazing tend to allocate greater resources to below-ground biomass than to sexual reproduction, with lower seedling recruitment rates but long generation times (Bond and Midgley, 2003). These characteristics are true of most Lepidosperma species. All Lepidosperma species are clonal perennials and most have been observed in the field by the author. These observations have shown that clones vary in size, from around 5–10 cm for L. inops to over 10 m for L. gladiatum. These clones provide a robust resource to withstand disturbance events and periods of low rainfall. Explicit data on the age of individual clones are not available, but assessment of clone size against annual growth rates suggests that plants of most species probably live for at least 50 years, and some clones are estimated to be in excess of 100 years old (R. L. Barrett, pers. obs.). Such longevity of individuals and resilience to disturbance means that Lepidosperma species can survive with very low recruitment rates and persist in some extreme environments. Given their persistence, they can form a very significant and stable component of the ecosystems in which they occur.

Specht (1981) classifies Lepidosperma species as evergreen hemicryptophytes. Almost all Australian Lepidosperma species that have been observed post-fire have shown capacity to resprout from rhizomes, with vegetative growth rapidly re-establishing or exceeding pre-fire biomass (Bradstock et al., 1997; Ashton, 2000; Barrett, 2000; Hopper, 2000; Brown et al., 2002; Morrison, 2002; R. L. Barrett, pers. obs.). In Lepidosperma, rhizome resources are often sufficient for flowering to occur in the first year following fire (Hopper, 2003; provided the burn season allows for floral initiation and development). Long-term monitoring of L. elatius in wet forests at Wallaby Creek in Victoria revealed a significant increase in density over a period of 50 years in response to the maturation and eventual decline of the eucalypt canopy in the absence of fire (Ashton, 2000). Lepidosperma limicola, a common species in sedge swamps in the Gibraltar Range of New South Wales, was equally abundant in burnt and unburnt sites (Williams and Clarke, 2006). In contrast, it should be noted that some populations of L. filiforme (?= L. flexuosum) in the Sydney region appear to be killed by fire, regenerating only from seed (Kubiak, 2009; R. L. Barrett and K. L. Wilson, pers. obs.). This is possibly due to the relatively shallow rhizomes and habitat in dense heath that is likely to promote hot fires (R. L. Barrett and K. L. Wilson, pers. obs.).

While able to resprout following fire, a form of L. laterale from north-eastern Queensland montane heath communities significantly decreased in abundance following fire, probably due to biomass reduction in a nutrient-limited environment limiting short-term recovery (Williams et al., 2005). Careful fire management was advised to ensure that fire frequency did not have a detrimental impact on this species. Correct classification of the fire response of each species is essential for sustainable management, particularly for rare or ecologically critical species (Gill and Bradstock, 1992). Cary and Morrison (1995) found that L. laterale is one of the few species in sandstone communities in the Sydney region that is able to tolerate high fire frequency (<5 years between fires). Adult plants are able to reproduce and seedlings are able to recruit and persist under these conditions, which may be promoting germination. Lepidosperma laterale also increased in cover following fire on Fraser Island, more so after low- rather than high-frequency fires (Spencer and Baxter, 2006).

Lepidosperma leptostachyum declined in abundance by at least 20 % under a variety of fire regimes in jarrah forest near Manjimup in Western Australia (Burrows and Wardell-Johnson, 2003). They suggested this decline was possibly due to decreasing rainfall patterns. This species has relatively shallow rhizomes that are often close to the litter layer and there may be a high level of mortality for this reason, particularly from hot fires. They also showed a decline in abundance of L. squamatum (s.l.) following spring fires that had an interval of 7–9 years.

Lepidosperma perteres from New Caledonia is rhizomatous and is able to resprout vigorously following fire, often dominating post-fire maquis vegetation (Jaffré et al., 1998). However, it may be negatively affected by frequent fires, which can promote the dominance of other plant species (McCoy et al., 1999). The prevalence of L. chinense in some grasslands in Hong Kong is also attributed to the promotion of fire in these areas (Kadoorie Farm and Botanic Garden, 2003).

Tozer and Auld (2006) measured the degree of leaf scorch in L. neesii in the Sydney region following fire. Their study showed that fire penetration was always less than the depth of the meristematic tissue, thus allowing the plants to resprout following fire. Lepidosperma neesii shows very strong preference for seasonally dry sites with low shade cover, decreasing in abundance in dry shaded areas, decreasing further in moist open areas and becoming very sparse in moist shaded areas (Tozer and Bradstock, 2003). This pattern of habitat preference corresponds to litter levels that provide fuel for fires.

Some Lepidosperma species are readily able to recover from disturbance. Ough (2001) found that L. elatius recovered with equal frequency following both clear-fell logging and wildfire, although total cover of this species was lower in the wildfire site. Partial habitat disturbance due to the development of log removal tracks for timber harvesting in Tasmanian forests had little impact on the density of L. sieberi (as L. concavum; Williamson and Neilsen, 2003). In contrast, Loyn et al. (1983) found that in East Gippsland, L. laterale increased in abundance following fire, but decreased in abundance in areas harvested for timber. Density of L. leptostachyum plants declined following logging operations in south-western Western Australia (Burrows et al., 2002). In urban locations, Lepidosperma species can show remarkable resilience. Rose and Fairweather (1997) found that L. filiforme, L. laterale and L. lineare (as L. gunnii) were all able to persist in the long term in urban bushland invaded by Pittosporum undulatum and numerous other weeds, while many other native species were significantly declining in abundance.

In areas of northern New South Wales that were previously used for plantation forestry of Eucalyptus grandis, but are now included in conservation estates, control of weeds in the understorey led to a significant increase in the density of the persistent species L. laterale (Cummings and Reid, 2008). Control of the invasive species bitou bush (Chrysanthemoides monilifera ssp. rotundata) in native bushland on coastal dunes in New South Wales led to an increase in cover of L. laterale though there were some short-term detrimental effects of herbicide spraying (Vranjic et al., 2011). Burrows and Wardell-Johnson (2003) suggest that L. squamatum (s.l.) disappears from long-unburnt tall karri (Eucalyptus diversicolor) forest, probably due to shading, although it may persist in the seed bank.

While some forms of disturbance are not overly detrimental, in the Buller District of New Zealand, grazing and trampling has resulted in the elimination of L. australe from dairy farms around the wetlands of the Kongahu Swamp (Sorrell and Partridge, 1999). Pelton and Conran (2002) found that vegetation rolling for firebreak construction in sandy heath communities in South Australia had a negative impact on two significant indicator species, L. carphoides and L. laterale.

While investigating energy content and flammability of common forest species in Tasmania, Dickinson and Kirkpatrick (1985) found that L. laterale had an energy content of around 20 000 J g⁻¹, an ash content (excluding silica) of 7–10 % and a silica content of 10 %, making them one of the least significant components of flammable material in the forest.

Germination and dormancy

Cyperaceae ‘seeds’ are technically a nutlet, the fruit comprising more than one carpel, but only a single seed, but as they are very small and one-seeded, they are sometimes referred to incorrectly as an achene (J. J. Bruhl, pers. comm.). Bruhl (1991) has confirmed that the thickened persistent scales at the base of the nutlet are in fact a perianth. Nutlet production is first dependent on inflorescence development. In Lepidosperma, the inflorescences are initiated during winter, with immature buds developing at this time, then undergoing a period of stasis over summer, maturing and flowering within weeks of breaking rains the following autumn (or occasionally after heavy summer rains) (R. L. Barrett, pers. observ.). This pattern is strong in the Western Australian species, but the timing is not as consistent in eastern Australian species (K. L. Wilson and J. J. Bruhl, pers. obs.). Lepidosperma spikelets are bisexual, with hermaphrodite flowers, most species developing several basal sterile bracts, followed by a functionally male flower and terminated by a bisexual flower (Bruhl et al., 1992; Bruhl, 1995; Goetghebeur, 1998). Spikelets are protogynous, the lower functionally male flower developing first, followed by the stigma of the bisexual flower, the stamens of the bisexual flower either developing later or remaining only partially developed (R. L. Barrett, pers. obs.). A few species such as L. jacksonense produce two bisexual flowers per spikelet (Barrett, 2007a). All species are considered to be wind-pollinated and population genetic studies suggest that they are primarily outcrossing (M. D. Barrett and M. Wallace, unpubl. data).

Potential nutlet production varies greatly between species of Lepidosperma, from 1–4 spikelets per inflorescence in L. tortuosum to over 1000 spikelets per inflorescence in L. elatius (Wheeler and Bruhl, 2000; R. L. Barrett, pers. obs.). Almost all species produce a single nutlet per spikelet; however, a few species have been observed to consistently produce two nutlets per spikelet (e.g. L. jacksonense, Barrett, 2007a). In Lepidosperma species, nutlets develop to approximately full size in a matter of weeks following fertilization (R. L. Barrett, pers obs.). These nutlets do not necessarily develop fully, with Wheeler and Bruhl (2000) finding that many nutlets appeared ‘full’ but were in fact lacking a developed embryo, a condition sometimes indicated by wrinkling of the nutlet surface (more prominent with age). Consistent winter rainfall is required to allow embryo fill, so with inflorescence development, two good seasons of rainfall are required for good nutlet development (R. L. Barrett, pers. obs.). This can be a rare combination in arid areas at the edge of the distribution of the genus (R. L. Barrett, pers. obs.).

Embryos were found to be small, only 0·12 mm long in L. clipeicola and only 0·40 mm long in L. elatius and L. laterale, and matched the Schoenus-type embryo morphology (Wheeler and Bruhl, 2000). Vanhecke (1974) studied the embryos of L. chinense, L. laterale (s.l.), L. longitudinale and L. sieberi (as L. squamatum) and found a similar size variation, from 0·20 to 0·32 mm long. The embryos are described as being asymmetric, with well-developed, S-shaped vascular tissue and with the germinal pore towards the base and to the side (Vanhecke, 1974). Of the four species currently held in the Millennium Seed Bank, seed weight (per thousand) ranges from 3·38 g for L. laterale to 7·05 g for L. urophorum (Royal Botanic Gardens Kew, 2008). These relatively small nutlets are more likely to be removed by ants (Westoby et al., 1990).

Only those nutlets naturally released from the inflorescence were considered developed by Wheeler and Bruhl (2000), an observation generally supported by Kodym et al. (2010). Pollen viability was very high (90–95 %) while nutlet viability was very low for L. clipeicola (0·5 %), and higher for L. elatius (72 %) and L. laterale (62 %), although no fruits were germinable due to an inability to overcome dormancy mechanisms (Wheeler and Bruhl, 2000).

In most Lepidosperma species, nutlets do not readily germinate without specific dormancy-breaking methods (Bell et al., 1993; Kodym et al., 2010; Dixon, 2011). Kullmann (1981) recorded some germination for L. gladiatum in pot trials, with seedlings emerging between 53 and 72 d after sowing. Many broad studies of natural germination rates have found very low recruitment for Lepidosperma species, even in cases where they are common components of the ecosystem (Lunt, 1997; Wang, 1997; Pettit and Froend, 2001; Fisher et al., 2009). Roche et al. (1997) found low levels of nutlet viability and no germination of Lepidosperma species was achieved from smoke treatments or non-smoke controls. Penman et al. (2008) found a significant germination response to heat treatment and a marginally significant germination response to smoke treatment for L. laterale from near Eden in New South Wales. Enright et al. (1997) found an occasional germination response to smoke in L. laterale from the Grampians National Park, western Victoria. Wills and Read (2002) found a germination response to heat treatment for L. sieberi (as L. concavum) from Gippsland, Victoria. Ward et al. (1997) found no response to heat or smoke in nutlets of L. tenue (= L. leptostachyum) from un-mined jarrah forest. However, they noted that the nutlets were collected in summer and as most fertile nutlets fall in late spring, they may have been using infertile nutlets. Physical disturbance of the soil seed bank of L. gladiatum, a species of coastal sand dunes, has been observed to promote increased germination (K. W. Dixon, pers. comm.).

Mammal associations

Twenty-six mammal species in Australia have been recorded making use of Lepidosperma species as detailed in Table 2 and references cited there. Two are recorded as making use of Lepidosperma tussocks as nest sites, including Gilbert's potoroo (Potorous gilbertii) and the western ringtail possum (Pseudocheirus occidentalis). Seven Lepidosperma species form part of the diet of five mammal species: swamp rat (Rattus lutreolus), western grey kangaroo (Macropus fuliginosus), common wombat (Vombatus ursinus), the endangered quokka (Setonix brachyurus) and the introduced common fox (Vulpes vulpes). The habitat or occurrence of 24 mammal species is specifically recorded as being associated with Lepidosperma species. These include a number of small mammals that depend on dense cover for shelter. The Lepidosperma plants probably also provide habitat for the prey of many species, although this has not been specifically documented.

Dense stands of Lepidosperma species can form stable habitats that are important to the long-term survival of a number of rare and threatened mammal species. Lepidosperma species provide habitat for the critically endangered Gilbert's potoroo and endangered quokka (along with a number of Australia's rarest birds; see below). Both species are found in dense vegetation cover in long-unburnt areas where along with the dominant rush Anarthria scabra, Lepidosperma species form an important component of the understorey (Vetten, 1996; Courtenay and Friend, 2004). The potoroo's nesting sites are usually under a dense cover of sedges (Friend, 2008). This species was considered extinct for around 100 years before being rediscovered near Two Peoples Bay on the southern coast of Western Australia (Sinclair et al., 1996). Bald Island is a small Western Australian island with a large amount of fringing vegetation dominated by L. gladiatum (Abbott, 1980), a species that provides refugial habitat for the Gilbert's potoroo and quokka. Lepidosperma species, which dominate sedgelands or the understorey of woodlands, form a major habitat for a number of rare species including the Tasmanian bettong (Bettongia gaimardi cuniculus), a species now extinct on the mainland (Taylor, 1992), the eastern barred bandicoot (Perameles gunnii), New Holland mouse (Pseudomys novaehollandiae), Kangaroo Island dunnart (Sminthopsis aitkeni), white-footed dunnart (Sminthopsis leucopus) and the swamp antechinus (Antechinus minimus subsp. maritimus) (Table 2).

Within habitats dominated by sedges, further segregation of mammal species can be found. The swamp rat (Rattus lutreolus) and bush rat (Rattus fuscipes) are both found in sedgeland in New South Wales that includes Lepidosperma species. However, the behaviour of the swamp rat effectively excludes the bush rat from the wetter sedgeland habitats (low, open vegetation dominated by Cyperaceae and Restionaceae) dominated by different Lepidosperma species (Lunney, 2008). The swamp rat is the only species recorded eating the rhizomes of a Lepidosperma species (L. filiforme) providing the marsupial rat with an important food resource (Braithwaite et al., 1978; Cockburn, 1981). Evergreen sedges can be an important dietary component for animals such as the western grey kangaroo, particularly once annual plant species have senesced (Shepherd et al., 1997). Under drought conditions, the rare species L. rupestre is heavily grazed by kangaroos in the Kalbarri Gorge, Murchison River (R. L. Barrett, R. D. Phillips and A. Faber, pers. obs.).

The western ringtail possum is usually found in areas with good coverage of Lepidosperma species in the understorey and may nest on the ground where these sedges are particularly dense (de Tores, 2008a). The endangered dibbler (Parantechinus apicalis) survives in long-unburnt heath communities where it is not especially habitat-specific, but does inhabit L. gladiatum thickets on islands in Western Australia (Bencini et al., 2001). The flute-nosed bat (Murino florium), a rare species from northern Queensland, is occasionally found in habitats with an understorey containing L. laterale (s.l.) (Kutt and Schulz, 2000). It is unlikely that this plant species is of any particular importance to the bat in these locations, but it is possible that the sedge provides habitat for insects on which the bat feeds. It is interesting that the introduced fox (Vulpes vulpes) has been recorded as regularly consuming the leaves of L. gladiatum on Cape Woolamai, Victoria (Norman, 1971).

Bird associations

Forty-three bird species in Australia and New Zealand have been noted making use of Lepidosperma species (Table 3, and references cited there). Thirteen are recorded as making use of Lepidosperma tussocks as nest sites. These records include the little penguin (Eudyptula minor) and short-tailed shearwater (Puffinus tenuirostris), with L. gladiatum in Western Australia and L. laterale in Tasmania providing protective cover and stability for sandy burrow substrates. Eleven bird species noted as nesting among Lepidosperma species are mainly found in coastal thickets and dense forest understorey vegetation. These birds include the endangered western whipbird (Psophodes nigrogularis leucogaster and nigrogularis), Mt Lofty Ranges subspecies of the southern emu-wren (Stipiturus malachurus intermedius), rufous bristlebird (Dasyornis broadbenti) and the vulnerable noisy scrub-bird (Atrichornis clamosus, Fig. 5). The actual Lepidosperma species involved is not specified in most records, although pilotbirds (Pycnoptilus floccosus) are recorded as nesting in L. elatius and noisy scrub-birds in L. sp. Manypeaks Large (R. L. Barrett RLB 2476) (recorded as L. longitudinale or L. persecans). Four of the birds nesting in Lepidosperma species have also been noted to incorporate Lepidosperma leaf material in their nest construction (the rufous bristlebird, pilotbird, noisy scrub-bird and western whipbird). The noisy scrub-bird is known to utilize L. effusum, L. gladiatum, L. sp. Manypeaks Large (R. L. Barrett RLB 2476) and the unusual L. tetraquetrum, which has rigid, four-angled culms that are flattened for nest construction (S. Comer, pers. comm.).

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Fig. 5.

Nest of the vulnerable noisy scrub-bird (Atrichornis clamosus) built in, and with leaves of, the rare sedge Lepidosperma sp. Manypeaks Large (R. L. Barrett RLB 2476), Manypeaks Range, Western Australia. (A) Female on ‘runway’ of nest (photo: Graeme Chapman). (B) Nest made primarily from sedge leaves (photo: Sarah Comer).

Ten Lepidosperma species form part of the diet of 12 bird species: emu (Dromaius novaehollandiae), southern emu wren (Stipiturus malachurus), three finch/firetail species and seven parrots, including the endangered New Zealand kakapo (Strigops habroptilus). The record of emus eating the nutlets of L. carphoides is particularly interesting, as emus are noted long-distance dispersers of plant species (e.g. Calviño-Cancela et al., 2006; He et al., 2008). The habitat or occurrence of a further 17 bird species is specifically recorded as associated with Lepidosperma species; these include many small forest understorey insectivores, including the grey fantail (Rhipidura fuliginosa) and four fairy wren species (Malurus spp.) as well as endangered ground-layer birds such as the spotted quail-thrush (Cinclosoma punctatum anachoreta) and western bristlebird (Dasyornis longirostris). It is also of interest that there are no records of a number of gramnivorous birds such as doves and pigeons feeding on Lepidosperma fruit, but this may be due to a lack of precise observations at the right time of year rather than an absence of utilization.

Reptile associations

Lepidosperma clipeicola is an important habitat plant for an arboreal snake, Stephens' banded snake (Hoplocephalus stephensii). This snake spends a great deal of its foraging time in the culms of L. clipeicola (Fitzgerald et al., 2002a, b). Prey species of this threatened snake are regularly caught while among dense stands of L. clipeicola culms and maintenance of healthy populations of this sedge are important for the long-term survival of the snake (Fitzgerald et al., 2004).

The federally endangered Blue Mountains water skink (Eulamprus leuraensis) inhabits swamps dominated by sedges including L. limicola, and protection of these habitats is critical for the long-term survival of the skink (Keith and Benson, 1988; LeBreton, 1996; NPWS, 2001). Along with the helmeted honeyeater (Lichenostomus melanops subsp. cassidix), the vulnerable swamp skink (Egernia coventryi) is found in a sedge-rich Eucalyptus camphora swamp with L. laterale, a habitat that is listed as endangered in Victoria (Turner and Rylah, 2003). Three skink species are found in Eucalyptus regnans forest with an understorey including L. elatius: the southern forest cool-skink (Niveoscincus coventryi), the southern water skink (Eulamprus tympanum) and the trunk-climbing cool-skink (Pseudemoia spenceri) (Brown and Nelson, 1993). Reptile ecology is poorly understood in these forest ecosystems and habitat complexity is considered critical to maintaining animal diversity (Lindenmayer, 2009). Michael et al. (2010) have shown that many reptile species occurring on granite outcrops require specific rock structures and specific vegetation structures to maintain viable populations and this needs to be considered in the management of granite outcrops where Lepidosperma species are often prominent.

Amphibian associations

Lepidosperma concavum has been recorded as potential breeding habitat for the vulnerable green and golden bell frog (Litoria aurea) on Bowen Island in New South Wales (Osborne and McElhinney, 1996). The rare Nornalup frog (Geocrinia lutea) and Karri frog (G. rosea) can be found calling from stands of L. effusum and L. tetraquetrum (Wardell-Johnson and Roberts, 1993). Lea's frog (Geocrinia leai) often lays its eggs in sedges overhanging wetlands and waterways (Pen, 1999). The slender tree frog (Litoria adelaidensis) requires dense vegetation including sedges fringing waterways for protective habitat (Pen, 1999).

Insect associations

The presence or absence of butterflies and moths with species- or genus-specific plant associations can be useful indicators in ecological restoration projects (Lomov et al., 2006). The three-spot skipper butterfly (Motasingha trimaculata) is dependent on Lepidosperma and Phlebocarya (Haemodoraceae) species as larval food plants and female adults remain close to these food plants (Symon, 1980; Braby, 2000; Sands and New, 2002).

The moth genus Elachista has a number of species with larvae dependent on Lepidosperma species and Kaila and Ståhls (2006) indicated the possibility of species-specific inter-relationships with further studies of their taxonomy required. Kaila (2011) has now shown that there are indeed a large number of species-specific relationships between Elachista and Lepidosperma. At least 34 Elachista species depend on Lepidosperma species for their larval stage, forming distinctive mines in leaves (Fig. 6; Table 4). For many more species, the host plant remains unknown. Multiple Elachista species may utilize a single species of Lepidosperma by occupying different parts of the same leaf; however, in most cases, Elachista species are restricted to a single host species (Kaila, 2011). Due to the lack of taxonomic knowledge in the genus Lepidosperma and a lack of current identification tools, many of the host Lepidosperma species could not be fully identified by Kaila (2011) and a summary of the current taxonomy as far as can be interpreted is presented in Table 4. There are numerous moth species in tussock grasslands of New Zealand (including Elachista species) that have larval associations with Cyperaceae species, but the genera of Cyperaceae involved were usually not recorded, so the utilization of Lepidosperma species remains uncertain (White, 2002).

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Fig. 6.

Elachistine moths associated with Lepidosperma species. (A) Elachista tetraquetri (host = L. tetraquetrum); (B) Elachista flavicilia (host = L. effusum); (C) mines of Elachista gladiograpta on L. gladiatum; (D) (1) mines of Elachista gladiatrix on L. gladiatum; (2) Elachista gladiograpta on L. gladiatum; and (3) Elachista spongicola on Machaerina arthrophylla (photos: Lauri Kaila). Scale bars: A, B = 2 mm.

The magnificent sunmoth (Synemon magnifica) relies on L. viscidum/L.concavum (and possibly L. laterale) as a larval food plant with the larvae feeding on the rhizomes of the plant (Common and Edwards, 1981; Common, 1990; Zborowski and Edwards, 2007). The white-banded sunmoth (Synemon directa) is thought to breed on L. gladiatum (M. Williams, pers. comm.; ABRS, 2009). Larvae of the endangered graceful sunmoth Synemon gratiosa from the Perth region primarily feed on Lomandra, but is also reported to feed on Lepidosperma species (Burbidge, 2004). Larvae of several other Synemon species are also known to feed on Lepidosperma species in Western Australia, but the exact species associations are yet to be determined (T. Edwards, pers. comm.). Larvae of Synemon parthenoides are known to feed on L. carphoides in South Australia and Victoria (Douglas, 2008). A newly recognized Synemon species, the Kangaroo Island sunmoth, restricted to Kangaroo Island, feeds on L. viscidum (Grund, 2011; A. Young pers. comm.; Fig. 7).

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Fig. 7.

The rare Kangaroo Island sun moth (Synemon sp.) on Lepidosperma viscidum, Kangaroo Island, South Australia. The larval casing can be seen in the bottom right of the image (photo: Andrew Young).

Larvae of several species of Miscera also feed on the rhizomes of Lepidosperma species, including M. desmotoma and two undescribed species in Victoria and M. centropis in Western Australia (Kallies, 2004; Zborowski and Edwards, 2007; T. Edwards, pers. comm.; A. Kallies, pers. comm.). Larvae of a Miscera species have been observed feeding on the roots of the rare species L. gibsonii when grown in pots in a glasshouse in Perth, but the origin of the moths is uncertain (B. Miller, pers. comm.). The sedge moth Glyphipterix gemmipunctella also feeds on several Lepidosperma species in eastern Australia (A. Kallies, pers. comm.).

While morabine grasshoppers are polyphagous, studies by Blackith and Blackith (1966) suggest that L. gladiatum, a species naturally occurring in their habitat, is specifically avoided. Predation of Lepidosperma culms and leaves by insects has only been observed on rare occasions (R. L. Barrett, pers. obs.) and there may be some form of defence such as the flavonols identified by Harborne et al. (1985). The high silica concentration in the leaves and culms may also be an effective deterrent (Norton, 1967). Six grasshopper species are known to feed on Lepidosperma species, Propsednura peninsularis apparently feeding only on L. laterale (Rentz et al., 2003; Table 5).

The katydid Chlorodectes loquax is associated with a Lepidosperma sp. in coastal New South Wales (possibly L. concavum) (Rentz, 1985). Seven of the 11 species of the katydid genus Kawanaphila (K. gidya, K. goolwa, K. iyouta, K. mirla, K. nartee, K. ungarunya and K. yarraga) are usually found in association with a variety of Lepidosperma species (including L. carphoides and L. tenue). The Lepidosperma species provide a protective habitat during the day with the katydids feeding on the pollen of a variety of plant species by night (Rentz, 1993, 2010). Kawanaphila species are possible dispersal agents for pollen due to hairs on their bodies effectively holding pollen (Rentz, 1993).

Many plant species have seeds that are distributed by ants. The activity of ants in native vegetation is very important and can be a key factor in the success of ecosystem function of restored communities (Grimbacher and Hughes, 2002). Berg (1975) appears to have been the first to observe myrmechory in Lepidosperma, after recording a decorator ant [Monomorium (Chelaner) sp. cf. rothsteini] collecting the nutlets of a Lepidosperma species. Siddiqi et al. (1976) recorded ants dispersing the nutlets of L. laterale. Drake (1981) found that the ant Aphaenogaster longiceps collected significant numbers of L. laterale nutlets on North Stradbroke Island, Queensland, and noted the hypogynous scales to function as an elaiosome type. Rice and Westoby (1981) found that L. elatius is a myrmecochore and suggested that L. filiforme, L. flexuosum, L. laterale, L. lineare, L. urophorum and L. viscidum (= L. concavum) may also be myrmecochores. Ants from the genera Iridomyrmex and Phedole were observed to remove seeds of L. laterale in cafeteria experiments conducted in natural habitats on Bribie Island, south-eastern Queensland (Barton, 1994). French and Westoby (1996) recorded myrmecochory in L. flexuosum, L. laterale and L. urophorum in fire-prone sites in the Sydney region. Barton (1994) determined the presence of lipids in the hypogynous scales, confirming their role as an elaiosome.

In December 2009, in the Bald Knob State Forest, northern New South Wales, the author observed that ants (an Iridomyrmex sp.) rapidly collected ten nutlets of L. laterale (s.l.) that were picked ripe from the plant and dropped on bare ground in the vicinity of an ant nest. The whole nut was collected (the ants gripping the relatively large nutlets by the hypogynous scales) and taken into the nest (Fig. 8). No discarded nutlets or hypogynous scales were observed around the entrance to the nest.

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Fig. 8.

Iridomyrmex sp. collecting mature nutlets of Lepidosperma laterale (s.l.) in the Bald Knob State Forest, northern New South Wales. Nutlets were gripped by the white hypogynous scales, an elaiosome type recognized by Berg (1975).

A number of ants (Chelaner, Iridomyrmex, Myrmecorhynchus, Prolasius, Solenopsis and Strumigenys species) are most common in tall open forests, often with L. elatius dominant in the understorey in sites at Wilsons Promontory in Victoria (Andersen, 1986). The golden spiny ant (Polyrhachis ammon) regularly builds its nests in tussocks of L. laterale in woodland in New South Wales (Gibb and Hochuli, 2003). Other unidentified ants have been observed preferentially nesting in Lepidosperma tussocks in Western Australia (R. L. Barrett, pers. obs.).

While there are some records of native bees collecting pollen (Houston, 2000), Lepidosperma species are all considered to be wind pollinated, as are most Cyperaceae (Goetghebeur, 1998). There are some exceptions (Friedman, 2011), and more observations would be beneficial as it is likely that bees collecting pollen do occasionally cause pollination. The implications of wind pollination for speciation in monocotyledons have been widely discussed (see Barrett et al., 2000; Friedman and Barrett, 2009a, b; and references therein).

Three native bee species have been recorded collecting pollen from L. ?gladiatum: Amegilla pulchra (Apidae), Megachile macularis (Megachilidae) and Stenotritus sp. SM7 (Stenotritidae) (Houston, 2000). Given that the majority of Lepidosperma species rapidly flower en masse following season-breaking rains in late autumn in south-west Western Australia and in the Mediterranean climate parts of South Australia and south-west Victoria, at a time when relatively few native plants are flowering, this may well be a critical source of pollen for these and other bee species at this time of year. As Lepidosperma flowers are protogynous, these pollen-collecting bees are unlikely to cause pollination of Lepidosperma species. The introduced European Honey Bee (Apis mellifera, Apidae) has also been noted to collect pollen from Lepidosperma species (Paton, 1996) and collection of pollen of L. gladiatum has been observed in Perth suburbs (M. Wallace, pers. comm.).

The collembola species Xenylla cf. obscura has been found living in Lepidosperma tussocks in South Australia (da Gama, 1979). A scale insect Paraonidiella cladii (as Chrysomphalus) is known to feed on Lepidosperma species (Fernald, 1903). Other scale insects have been observed, but not formally identified (Fig. 9). Slater (1975, 1976) recorded L. squamatum (s.l.) (as L. angustatum) as a host plant for both nymphs and adults of the sap-sucking bug Ontiscus obscurus (Lygaeidae), which feeds on the nutlets of this species.

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Fig. 9.

Scale insect on the rare Kalbarri sword sedge (Lepidosperma rupestre), Kalbarri Gorge, Western Australia.

Snail associations

Regan et al. (2001) and Taylor et al. (2003) have recorded L. elatius as a component of the habitat of a rare land snail (Tasmaphena lamproides) in north-eastern Tasmania. The introduced common garden snail (Helix aspersa) is commonly found on L. gladiatum on the Swan Coastal Plain in Western Australia (R. L. Barrett, pers. obs.).

Arachnid associations

While sampling Lepidosperma specimens, a large number of unidentified spider species have been found foraging, or building webs in the tussock bases (R. L. Barrett, pers. obs.). One is most likely from the ground-dwelling spider genus Miturga (Miturgidae) which commonly builds silken retreats in protected sites such as in sedge tussocks or at the base of shrubs (M. Rix, pers. comm.; Fig. 10). Lepidosperma australe is a habitat species for the rare red katipo spider (Latrodectus katipo) in New Zealand (Patrick, 2002). In Western Australia, five short-range endemic spiders, the synotaxid Calcarsynotaxus benrobertsi, the archaeids (assassin spiders) Zephyrarchaea barrettae, Z. melindae and Z. robinsi and the malkarid Perissopmeros darwini, are all found under or near the shaded leaves of Lepidosperma species (mainly L. sp. Bluff Knoll Robust (G.J. Keighery 12595) and possibly L. persecans; Rix et al., 2009; Rix and Harvey, 2012a; S. Barrett, pers. comm.). These spider species are only known from a few peaks and gullies in the Stirling Range National Park (Rix et al., 2009; Rix and Harvey, 2012b). Similarly, Main's assassin spider Zephyrarchaea mainae is restricted to litter lodged in the crown of Restionaceae species, L. gladiatum and L. effusum, which grow under long-unburnt stands of weeping peppermint (Agonis flexuosa (Willd.) Sweet; Rix and Harvey, 2009, 2012a). This habitat also supports a range of smaller spiders on which the assassin spiders feed (Rix and Harvey, 2009). Assassin spiders represent a relictual lineage with similar fossil relatives dating back to the Jurassic (150 Mya) (Platnick, 1991; Rix and Harvey, 2012a, b).

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Fig. 10.

Silken retreat from a juvenile ground-dwelling spider in the genus Miturga (Miturgidae) built in the base of a large Lepidosperma tussock, Mount Lesueur, Western Australia.

Freshwater organisms

Freshwater pools in creeks and rivers provide habitat for a wide range of organisms. In summer months, numerous animals, including fish, lampreys and freshwater crayfish, require shade provided by fringing vegetation during the day. Sedges such as Lepidosperma play an important role in many riparian areas (Pen, 1999). Three species of freshwater crayfish, the Dunsborough burrowing crayfish (Engaewa reducta), the Margaret River burrowing crayfish (Engaewa pseudoreducta) and the Walpole burrowing crayfish (Engaewa walpolea), are found in southern Western Australia and all are considered to be federally endangered (Department of Environment and Conservation, 2008). These species occur in small swamps and creeklines that are dominated by dense vegetation (including several Lepidosperma species) that provides cover for their fragile burrows in the banks of pools (Burnham et al., 2007). In north-eastern Tasmania, the endangered Scottsdale burrowing crayfish (Engaeus spinicaudatus) is found in creek and swamp habitats where L. elatius is a common part of the vegetation cover and L. filiforme is also occasionally present (Wapstra et al., 2006). Traylor et al. (1996) have identified 192 aquatic invertebrate, fish and amphibian species in south-western Australian ecosystems, many of which are likely to be reliant on the condition and species composition of wetland vegetation where Lepidosperma species are often prominent. Specific associations with wetland vegetation patterns and individual plant species are yet to be studied for the majority of these animal species.

Macroinvertebrates

Dense riparian vegetation, including L. tetraquetrum, which can form monospecific stands along creeklines, is highly beneficial to the health of macroinvertebrate communities in these ecosystems (Armstrong et al., 2005).

Microbial activity

The combination of living stands and dead litter of L. longitudinale supports microbial activity, which captures excess phosphorus from agricultural systems and incorporates it into the wetland sediments (Chambers, 1988; Chambers et al., 1993). Sedge communities bounding wetlands, waterways and estuaries act as an important nutrient trap (Pen, 1999; Brearley, 2005). Lepidosperma longitudinale often dominates wetlands with impeded drainage (Benson, 1981; Brearley, 2005). While little is known of specificity (or even taxonomy), amoebae have been found associated with the rhizosphere of L. semiteres (Foster, 1988).

Fungal associations

While smuts are considered detrimental to the host plant, reducing seed production through infection of the inflorescence, Savile (1979) and Lutz et al. (2012) have highlighted the value of rust and smut fungi in providing an independent assessment of evolutionary trends in the Cyperaceae. Two smut species were described from Lepidosperma species by McAlpine (1910) as Tolyposporium lepidospermae and T. rodwayi, both now included in Moreaua. Websdane et al. (1994) recorded smuts on five Lepidosperma species from Western Australia, assigning them to the genus Tolyposporium. Vánky and Shivas (2008) have now recorded five smut fungi on 15 Lepidosperma species (Table 6), including the monotypic genus Heterotolyposporium which is only known from L. ensiforme in Tasmania (Vánky and Shivas, 2008; Lutz et al., 2012). Additional records have recently been made from a broad range of Lepidosperma species from south-western and south-eastern Australia but the fungal species are yet to be identified (R. L. Barrett, M. D. Barrett, J. J. Bruhl and K. L. Wilson, pers. obs.; Fig. 11).

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Fig. 11.

Fungal smut-infected spikelets of Lepidosperma costale at Wubin Rocks, Western Australia.

McAlpine (1902) described the ascomycete Metasphaeria lepidospermae from a Lepidosperma species in Victoria near Werribee as having a significant impact on the species, actually killing hundreds of plants. The ascomycete Nemacyclus gilvus was named from dead leaves of L. laterale (Rodway, 1918; Dennis, 1958).

The septorioid fungus Clypeopycnis lepidospermatis (teleomorph Mycosphaerella lepidospermatis) occurs on L. gladiatum (Priest, 2006). The generic placement of this fungus is in doubt and it possibly represents a Cyperaceae-specific genus currently only known from L. gladiatum (Priest, 2006).

Cooke (1891) described Anthostomella lepidosperma from a Lepidosperma species in Victoria. Anthostomella lepidosperma is now considered to be a synonym of A. leptospora (Lu et al., 1999). Coniosporium pterospermum (= Arthrinium pterospermum) has been recorded from Lepidosperma in Victoria (McAlpine, 1895). Hennings (1901) described the Sordariomycete fungus Pestalotia lepidospermatis from L. angustatum in Western Australia. McAlpine and Tepper (1895) described a new stone-maker fungus (Laccocephalum basilapiloides = Polyporus basilapidoides) from the mallee of South Australia, noting that it was regularly found among tussocks of L. viscidum (s.l.).

Mycorrhizal and microbial associations

Generally, Cyperaceae are considered to be non-mycorrhizal (e.g. Powell, 1975). Lepidosperma squamatum (s.l., as L. angustatum) has been recorded as being ‘usually uninfected’ by mycorrhizal fungi (Lamont, 1984). More recently, Meney et al. (1993) have recorded seasonal infection by arbuscular mycorrhizal fungi (Acaulospora sp. and Glomus sp.) in L. gracile (probably = L. leptostachyum). Some authors consider it unlikely that these records represent a true mycorrhizal relationship, although this is difficult to prove conclusively (Brundrett, 2009). Brundrett (2002) suggests that the presence of non-mycorrhizal nutrient acquisition through the presence of dauciform roots may have facilitated the success of the Cyperaceae. This is a common strategy in soils with very low available phosphorus (Lambers et al., 2008). It may be that a mycorrhizal relationship is only present under specific circumstances. In studies of the normally non-mycorrhizal genus Hakea, Boulet and Lambers (2005) found in H. verrucosa, a species with cluster roots similar in function to the dauciform roots found in Lepidosperma, that arbuscules were present in roots in ultramafic soils with high nickel and low phosphorus concentrations. It may be that Lepidosperma species (and other Cyperaceae) are mycorrhizal under certain environmental conditions, which disadvantage the carboxylate-releasing strategy of dauciform roots. Perrier et al. (2006) and Lagrange et al. (2011) have confirmed that arbuscular mycorrhizas are regularly found in the roots of the metallophytic species L. perteres in the metal-rich ultramafic soils of New Caledonia. Muthukumar et al. (2004) concludes that many Cyperaceae should be considered to be mycorrhizal, although often only under particular environmental conditions, with the specific benefits of these relationships still remaining unknown.

Early studies of plant species influence on microbial presence in the rhizosphere in sandy heath in Victoria by Thrower (1954) found a large number of microorganisms associated with the root zone of L. sieberi (as L. concavum): two Oomycetes. seven Zygomycetes. seven Sordariomycetes. two Saccharomycetes. 29 Eurotiomycetes. one Leotiomycete. two Dothideomycetes and one Actinobacteria. The exact nature and ecological implications of the relationship between the plant and rhizosphere mycota remain to be demonstrated. The Sordariomycete fungus Coniella duckerae (Yip, 1987) was described from the rhizosphere of L. sieberi (as. L. concavum).

Pathogenic infection

While it appears that some level of infection can occur (Phillips and Weste, 1984), all Australian Lepidosperma species are considered to be resistant to Phytophthora cinnamomi, possibly due to their ability to produce new roots beyond the infection zone relatively quickly (Phillips and Weste, 1984; Weste et al., 2002). Several species appear to benefit from reduced competition following the death of susceptible taxa in infected areas (Weste, 1981; Podger et al., 1990; Duncan and Keane, 1996; Shearer and Dillon, 1996; Kirkpatrick and Harris, 1999; Cahill et al., 2008; Dunstan et al., 2008; Mordecai, 2011). Weste and Kennedy (1997), Weste et al. (2002) and Weste (2003) recorded a significant long-term increase in the density of L. semiteres in the Grampians, Victoria, in sites affected by P. cinnamomi. Weste (1981) recorded L. sieberi (as L. concavum) becoming dominant following the death of susceptible species due to P. cinnamomi infection near Melbourne, Victoria. Podger et al. (1990) isolated P. cinnamomi from the roots of L. sieberi (as L. concavum), but they did not observe any level of pathogenicity. Shearer et al. (2007) caution that Lepidosperma species may still be at risk from associated habitat change, noting some decline in L. angustatum in southern Western Australia without any signs of direct infection by P. cinnamomi. Changes in plant community structure due to the invasion of P. cinnamomi may have significant effects on animals reliant on plant cover for protection and resistant species such as Lepidosperma become even more important in these situations (Wilson et al., 1994).

Shearer et al. (1998) found that Lepidosperma species are also resistant to the pathogenic fungus Armillaria luteobubalina in coastal areas of Western Australia.

I thank Matt Williams (Department of Environment and Conservation, Perth) for comments on Synemon spp.; Myles Menz and Ryan Phillips (Kings Park & Botanic Garden, Perth) for assistance in locating fauna literature; Ryan Philips and Alea Faber (Kings Park & Botanic Garden, Perth) for assistance with fieldwork; Juliet Wege (Western Australian Herbarium, Perth) provided an unpublished estimate of the number of species of Stylidium; Karen Wilson (Royal Botanic Gardens, Sydney) and Jeremy Bruhl (University of New England, Armidale) provided comments on the manuscript and unpublished field observations; Matt Barrett and Mark Wallace (Kings Park & Botanic Garden, Perth) provided assistance in the field and observations; Alan Anderson (CSIRO, Darwin) identified the ant in Fig. 8 to genus based on photographs; Ted Edwards (CSIRO, Canberra) Andrew Young (Kangaroo Island, South Australia) and Axel Kallies (Walter and Eliza Hall Institute of Medical Research, Victoria) kindly provided unpublished information on butterflies and moths; Michael Rix and Mark Harvey (Western Australian Museum, Perth) supplied references on spiders in Western Australia; Sarah Barrett (Department of Environment and Conservation, Albany) provided field observations on a number of species; Ben Miller and Kingsley Dixon (Kings Park & Botanic Garden, Perth) and Hans Lambers (The University of Western Australia, Perth) and two anonymous referees provided comments on earlier drafts of this manuscript that significantly improved the structure of the paper. Zoe Davies is thanked for her attention to detail in reviewing this paper. Images were generously provided by: Michael Shane (The University of Western Australia, Perth) – Fig. 4; Sarah Comer (Department of Environment and Conservation, Albany, Western Australia) and Graeme Chapman (http://www.graemechapman.com.au/) – Fig. 5; Lauri Kaila (Finnish Museum of Natural History, Finland) – Fig. 6; Andrew Young – Fig. 7. This work was supported by an Australian Postgraduate Award to the author from the Commonwealth of Australia.