Unusual, human-mediated prevalence of epiphytes in semi-arid New South Wales, Australia

Study area

The study area is focused on Gingie station, ~30 km north-west of Walgett, in semi-arid north-western New South Wales (Fig. 1). Average annual rainfall for Walgett is 470 mm, with ~60% of rainfall falling in the summer months from October to March inclusive (data for Walgett Airport and Council Depot combined, 1879–2021; Bureau of Meteorology, http://www.bom.gov.au/climate/data/, accessed March 2022). Rainfall is variable among years, with 16% of years receiving <300 mm annual rainfall and 10% of years receiving >700 mm. Extended dry periods are common, with Foley’s drought index (Foley 1957) falling below −1 (two-thirds of expected rainfall in the 3 years prior to any given month) nine times since records began in 1879 (Fig. 2). Summer temperatures are hot, with average maximum temperatures of >34°C from December to February. Winters are mild (average daily maximums 18–21°C from June to August) with cool nights (average daily minimums <5°C from June to August).

Fig. 1.

Study area showing major towns and rivers, places mentioned in the text, epiphytes recorded (green circles; epiphytes that were measured are marked with a black dot in the centre of the green circle), and areas (red crosses) and tracks (grey lines) searched in southern Queensland and northern New South Wales. The area containing the Barwon River palaeochannels is shaded yellow.

Fig. 2.

Foleys drought index, showing expected rainfall in the 3 years prior to any given month, for Walgett, New South Wales, 1883–2023 (data sourced from Bureau of Meteorology, http://www.bom.gov.au/climate/data/, accessed March 2022).

The landscape of Gingie and surrounding properties is dominated by low sandhills and swamps that mark a palaeodrainage system of the Barwon River (Fig. 1), where water still runs underground. These palaeochannels are clearly visible on satellite imagery and extend from the present Barwon River, an upper tributary of the Darling River, 160 km north into southern Queensland. This area is here termed the ‘Barwon palaeochannels’. There is no permanent surface water in the palaeochannels, although there are Aboriginal and European wells accessing shallow groundwater, and many ephemeral swamps. Most of the earth tanks in the area were built on semi-permanent swamps. The Big Warrambool, which heads in southern Queensland, runs through the western part of the palaeochannels and into the Barwon River, but does not contain permanent water. The closest permanent surface water is at Cumborah Springs, 15 km north-west of Gingie.

Aboriginal people have inhabited inland New South Wales for at least 45 000 years (Hiscock 2008). The Barwon palaeochannels is known as a ‘border’ region between Gamilaraay/Gomeroi and Yuwaalaraay territories, and is bisected by a major Aboriginal pathway (now roughly followed by the Stock Route along the Cumborah–Walgett road) between the Barwon River and Cumborah Springs to the north-west and the ephemerally flooded Narran Lake to the west. After being driven away from the rivers, Aboriginal people lived in camps around Gingie and at surrounding stations from the 1850s until the 1940s (Fields 2001). Their descendants mostly live in the nearby towns of Walgett and Lightning Ridge and maintain strong spiritual, cultural and familial connections with Country. In the words of Gamilaroi/Yuwaalaraay women and co-authors of this study Priscilla Reid-Loynes and Rhonda Ashby:

Ngali winangaylanha dhawunda Gamilaraaygu nhalay.

[We acknowledge that this is Gamilaraay land.]

Yilaambiyali dhawun nhalay, maran.gu ngiyaningu galumay.

[From the beginning, our ancestors have cared for this land.]

Dhawun nhalay ngiyani dhirral, nhama ngarranmaldanha bigan wilay, winangali, galumali.

[This land is our teacher, it shows/guides us the lore to live, to listen to connect.]

Galumay ngiyani galligu, dhawun.gu, dhulugu dhawunda Gamilaraaygu. Ganunga ngiyaningu dhiiyaan.

[We have always cared for our waterways, country, plants and trees on Gamilaroi country. They are our family.]

Ngiyani Wayamaa winangaya, ganungawu.

[Let us respect the Elders, all of them.]

Nguwa yanayindaay, nguwa yanaylandaay, nguwa yanangayiylandaay.

[Who walked here long ago, now and in the future.]

A feature of the Barwon palaeochannels is the high density of Culturally Modified Trees including hundreds of scar trees where bark has been removed by Aboriginal people for constructing shelters, watercraft and containers (Long 2005), and numerous ring trees whose growing limbs were manipulated by Aboriginal people to form circles or rings (Power 2013), as documented and photographed by Jane Pye on the ‘Scar Trees’ website (https://scartrees.com.au). Where possible throughout this manuscript, we provide Gamilaraay/Yuwaalaraay as well as modern common names for plants mentioned, as compiled by McKerney and White (2011) and Menkins (2012).

Gingie was one of the first pastoral stations in the region, being taken up around 1843. In 1902, Gingie encompassed 73 650 ha, but over time blocks have been split off and today it is ~22 250 ha. The Pye family have held this station since 1916. Clay plains have largely been cleared for agriculture, but the palaeochannel woodlands on sandy rises remain largely intact apart from patchy but widespread ringbarking, wherein a strip was cut around the circumference of the base of the trunk to kill the central trunk and any higher limbs, practised from the 1880s (many of these trees subsequently resprouted) and poisoning of eucalypt trees in the 1980s. There are areas of smaller outer palaeochannels to the east of the main system, within predominantly cleared cropping lands.

Locating and recording epiphytes

Epiphytes were intensively searched for and recorded on Gingie and surrounding properties by Jane Pye in collaboration with local Indigenous people, particularly Gamilaraay/Yuwaalaraay Elder Allan Tighe, between 2018 and 2023. The core area searched intensively, here termed the ‘Gingie palaeochannels’, is ~30 km long and 15 km across. Much of this area is not accessible via vehicle tracks, and an all-terrain vehicle was primarily used. Remnant woodland on the outer Barwon palaeochannels was also searched for epiphytes. Some vines and climbing shrubs are relatively common as epiphytes in semi-arid Australia, notably gargaloo (Parsonsia eucalyptophylla), nepine/guwiibir (Capparis lasiantha) and native jasmine (Jasminum didymium), as are annual and perennial grasses, forbs and sub-shrubs. Only non-climbing woody shrubs and trees are considered here.

For each epiphyte found, host and epiphytic species were recorded, and whether the host and epiphyte were alive or dead. Approximately 70% of epiphytes found during these surveys were noted as ‘big’, ‘medium’, ‘small’ or ‘tiny’; the others were located opportunistically, and this information was not systematically recorded. We measured the diameters of a subset of these, and size classes were approximately defined as: ‘big’, largest stem >15 cm diameter at 10 cm height; ‘medium’, main stem 5–15 cm diameter at 10 cm; ‘small’, main stem 1.5–4 cm diameter; and ‘tiny’, saplings or seedlings, main stem <1 cm diameter. Obvious human modification to the host tree, including to create the host site (trunk or branch hollows, central crotch or scar), was often noted but not recorded systematically.

In April 2021 and April 2022 we visited 189 epiphytes throughout the Barwon palaeochannels, encompassing all species represented by at least five individuals (Table 1) and aiming for as broad a geographic spread across the palaeochannel area as possible (Fig. 1). We recorded GPS location, broad habitat, host species and diameter at breast height (DBH) of host (where there were multiple stems at 1.5 m, each stem was measured separately); whether the tree had been modified by humans through removal of bark (Long 2005), cutting of limbs, ringbarking or poisoning (deduced from growth habit, presence of old ringbarking cuts or poison holes and local knowledge); and hollow characteristics including size (measured as surface area of hollow where it abutted trunk or branch), height above ground, architecture and whether it appeared to be created by anthropogenic activity (either pre- or post-contact). For each epiphyte, we identified the species and recorded its stem diameter at 10 cm height and estimated its height. We also recorded the distance to the nearest human-modified tree. Where anthropogenic modification involved cutting of branches, we recorded whether the cut was apparently made by a stone (rough, uneven cut) or steel (smooth, clean cut) axe, although in some cases this was impossible to discern, and these were noted as being of ambiguous origin.

Regional surveys and analyses

We searched for epiphytic occurrences of trees and shrubs in other areas of arid and semi-arid eastern Australia through surveys in poplar box and coolabah woodlands in similar climatic zones between September 2020 and January 2024 (Fig. 1). We drove roads throughout the distribution of Eucalyptus populnea and Eucalyptus coolabah in semi-arid southern Queensland and northern New South Wales, including along the Barwon palaeochannels to the north of Gingie (here termed ‘Palaeochannels north’), and situated survey sites where we saw an epiphyte from a slow-moving vehicle or in other areas of potential habitat (i.e. remnant woodland dominated by E. populnea, Eucalyptus largiflorens or E. coolabah). Such ‘windshield surveys’ have some drawbacks; however, they are able to cover large areas where roads pass through representative examples of widespread target habitat (Elzinga et al. 2001). For each survey site, we recorded broad habitat, approximate area searched, time spent searching, total number of potential host hollows seen, density of hollows per hectare, abundance of shrubs (abundant, common, scattered, rare), total number of potentially epiphytic species (defined as those documented occurring as epiphytes in this study) occurring at the site, and presence and density of anthropogenically modified trees (Aboriginal or European).

All data were entered into Excel spreadsheets and mapped in ArcGIS and Google Earth. The factors influencing presence of epiphytes at search sites were investigated using Generalised Linear Models in the R package (R Core Team 2022). To complement the field variables described above, the average relative humidity at minimum temperature, average relative humidity at maximum temperature, average annual rainfall and average evaporation were extracted for each site from SILO, a modelled surface informed by a network of weather stations (Jeffrey et al. 2001). Multiple models were attempted using a combination of variables. Non-significant variables were excluded, and models were chosen based on the lowest Akaike information criterion (AIC). A log transformation was used to normalise variables when required and data were checked for heteroscedasticity. The random effect of site was tested for and removed after being found non-significant. Two models were retained: one using the densities of anthropogenically modified trees and hollows to account for the area searched, and one based on the presence of anthropogenically modified trees and hollows to eliminate any area-based bias.

We mapped the distribution of all species with >20 epiphytic occurrences from the Australasian Virtual Herbarium (AVH 2023) and overlaid this with vegetation mapping of ecosystems dominated or co-dominated by E. populnea, E. coolabah and/or E. largiflorens, the most common host species. We also included communities dominated by Eucalyptus brownii, which is closely related to, and replaces, E. populnea in the north-east of its range and has a similar growth habit. In Queensland, all Regional Ecosystems (REs) with E. populnea, E. coolibah, E. brownii or E. largiflorens described as dominant or codominant were included (Queensland Herbarium 2021). REs dominated by mulga but with emergent or scattered poplar box were not included. In New South Wales, Plant Community Types dominated by one or more of these eucalypt species were extracted (Department of Planning and Environment 2022; Roff et al. 2022). This allowed us to identify areas with potential epiphyte occurrence in eastern Australia.

We also questioned 15 ecologists and land managers who live and work in inland eastern Australia about whether they had observed trees or shrubs growing in other trees. Together these informants had >400 years of experience working in these environments. If the respondents answered affirmatively, we requested GPS points or location descriptions, photos, identification of host and epiphyte species, and any other observations.

Barwon palaeochannel survey

In total, 712 woody epiphytes were documented in the Barwon palaeochannel system, including 33 ‘doubles’, where two epiphytes were living in the same host tree, and three ‘triples’. The core area of epiphyte occurrence, the Gingie palaeochannels (Fig. 1), contains 88% of those documented and covers ~40 km², within which there is a density of >10 epiphytes km⁻². Fifty-six epiphytes were found in the same palaeochannel system to the north-east of Gingie, and 34 were found in outer palaeochannels to the east of the main system in country that has mostly been cleared for cropping. All of these epiphytes are hereafter referred to as the ‘Barwon palaeochannel’ epiphytes.

The majority of the 673 host trees (accounting for double and triple epiphytes in a single tree) were poplar box/bibil (E. populnea, 90%), and 6% were coolibah/gulabaa (E. coolabah). Five dead host trees may have been either E. coolabah or E. populnea, and one E. coolabah or E. largiflorens. There were nine host cypress pines/guraay (Callitris glaucophylla), five black box/guburuu (E. largiflorens), four ironwood (Acacia excelsa), and one each of whitewood (Atalaya hemiglauca), belah/murrgu (Casuarina cristata), river red gum/yaraan (Eucalyptus camaldulensis), leopardwood/bagala (Flindersia maculosa), needlewood (Hakea leucoptera), and supplejack/ganyanay (Ventilago viminalis). Over 80% of host trees were alive; the remainder had died naturally, had been poisoned in the 1980s or were cut stumps. Numerous host trees had been ring-barked or cut for timber historically (Fig. 3d), but the majority of these were resprouting.

Fig. 3.

Examples of epiphytes documented on the Barwon River palaeochannels, north-western New South Wales: (a) large Ehretia saligna growing in hollow created by falling branch; (b) Capparis mitchellii growing in apparent stone axe cut in Indigenous-created scar on Eucalyptus populnea; (c) Apophyllum anomalum in central crotch of multi-stemmed Eucalyptus coolabah on outer Barwon palaeochannels; (d) large Geijera parviflora in mid-trunk of multi-stemmed Eucalyptus populnea that has likely resprouted after ringbarking in the 1920s; (e) multi-trunked Eucalyptus populnea with four Indigenous-created scars (two visible in image) and Capparis mitchellii epiphyte; (f) hollow in a multi-trunked Eucalyptus largiflorens on the Ginghet south-west of the Barwon palaeochannels, showing soil accumulation. An image archive of epiphytes on the Barwon palaeochannels is available at www.scartrees.com.au/galleries.

Twenty-one tree and shrub species were recorded growing as epiphytes in the Barwon palaeochannels. Peach bush (Ehretia saligna) and wilga/dhiil (Geijera parviflora) were the most common epiphytes, comprising 24% and 23% of all epiphytes recorded, respectively (Fig. 3a, d). Both species were strongly associated with E. populnea and were not recorded in E. coolabah hosts with the exception of a single E. saligna. Currant bush/wayaara (Apophyllum anomalum, n = 70; Fig. 3c), boonaree/bunbarr (Alectryon oleifolius, n = 45), supplejack/ganayanay (Ventilago viminalis, n = 41), native orange/bambul (Capparis mitchellii, n = 39; Fig. 3b, e), whitewood/birraa (Atalaya hemiglauca, n = 32), budda/badha (Eremophila mitchellii, n = 29), quinine/gadibundu (Alstonia constricta, n = 245), boobialla/buubiyala (Myoporum montanum, n = 19), gumby gumby/guwiirra/miyaymiyaay (Pittosporum angustifolium, n = 18), and shrubby riceflower (Pimelea microcephala, n = 17) were all well represented as epiphytes. The remaining eight species are rare epiphytes in the study area, with between one and three examples of each, except white cypress/guraay (C. glaucophylla) with seven epiphytic occurrences recorded (Table 1). Sixteen epiphytes were dead with no bark remaining and were unable to be identified, and two epiphytes were tiny seedlings or resprouts that could have been A. constricta, E. saligna, P. angustifolium or G. parviflora.

Of the epiphytes documented, 95% were alive, and most of these were healthy with no dead branches and many were flowering and/or fruiting. The only species of epiphyte with a relatively high proportion (24%) dead was E. mitchellii. A range of size classes was recorded for all epiphyte species, indicating a range of plant ages. Where size class was recorded (n = 304) or diameter measured (n = 169), 25% were classified big, 21% medium, 32% small and 22% tiny (see Methods for definitions of size classes). A small number of live epiphytes had old, dead stems, indicating that they had died back, probably during dry times, and then resprouted. The Gingie and outer palaeochannels had a wide range of epiphyte sizes but were the only areas to contain ‘big’ epiphytes; all epiphytes found in the northern palaeochannels were of <15 cm diameter and 79% were of <5 cm diameter.

Detailed measurements

In total, 176 epiphytes and their 159 host trees were measured in the Barwon palaeochannels. The majority of host trees (n = 149) were E. populnea, with seven E. coolabah, two F. maculosa and one C. glaucophylla. Most host eucalypts were large, and the majority (82%) were multi-stemmed; 57% had at least three stems and 23% five or more stems. Average DBH of the largest stem was 46 cm (range 16–120 cm, excluding the two leopardwoods that had DBHs of 21 cm and 8 cm). On all but six host trees, DBH of the largest stem was at least 20 cm.

Almost 70% of host trees had been modified by humans in some ways (mostly with cut branches or stumps, from both stone and steel axe cuts, scar trees or ringbarked; Fig. 3b, d, e). Others may have been modified (e.g. branches cut or tree burnt historically, resulting in a multi-stemmed habit; Burrows 2013; Rayner et al. 2014), but unless this was obvious, these were not classified as anthropogenically modified. Those host trees that were not obviously modified themselves were typically <100 m from an unambiguous Culturally Modified Tree, usually a scar tree, which are common throughout the Barwon palaeochannels.

At least 93 of the 170 hollows that hosted epiphytes (55%) were directly anthropogenically created (encompassing 46 apparently Indigenous-created and 47 created post-contact through cutting branches or historical ringbarking), with a further seven potentially of anthropogenic (Indigenous) origin. Thirty hollows were natural (obviously created by fallen branches or in the central crotch of an apparently unmodified multi-stemmed tree); the remaining 40 are considered probably of natural origin but occurred in modified trees and their formation may have been assisted by human modification of the tree.

Fifty-seven host hollows were created by cutting of a branch or stump; 12 of these cuts appeared to have been created by stone axes (characterised by rough edges, as though made with a blunt object), 23 were unambiguously steel axe (including one chainsaw); the origins of the remainder were ambiguous. Nineteen host hollows were directly created by Indigenous scars where bark had been removed for materials. Fifty-three hollows occurred in the central ‘bowl’ of a trunk created by multiple stems, which in many cases probably resulted from cutting or burning of a central stem.

Hollows hosting epiphytes were, on average, 0.85 m above the ground (range 0–4 m). Average hollow size was 1550 cm² (range 12–56 000 cm²); however, this was highly variable, skewed by a few very large hollows, with a median hollow size of 431 cm². Over 80% of hollows were horizontal; aspect where it existed was highly variable and displayed no consistent pattern.

Of the 176 epiphytes measured (Table 1), 170 were alive. Average diameter at 10 cm of the largest stem was 10.4 cm (0.3–45 cm) range. One-quarter were multi-stemmed. Average height of epiphytes was 3 m (0.1–15 m). C. mitchellii, Alectryon oleifolium and G. parviflora tended to be the largest epiphytes, whereas the shrubs P. microcephala and M. montanum were the smallest. E. saligna and A. anomalum both occasionally grew into large trees, but were mostly represented by smaller specimens <10 cm in diameter.

Regional epiphyte surveys

Over 5000 km of gazetted roads and property tracks through woodlands dominated by E. populnea, E. coolabah and E. largiflorens in southern Queensland and northern New South Wales were driven at 40–70 km h⁻¹ with a passenger observer scanning for epiphytes, and 130 areas of 0.25–100 ha were searched on foot; 312 individual woody epiphytes were documented during these surveys and 82 of these were measured (Fig. 1, Table 2).

The largest cluster of epiphytes (n = 213) found during regional surveys centred on Ginghet and Marra Creeks, ~50 km south-west of the Barwon palaeochannels. These were spread over ~500 km² and were recorded during on-foot surveys between May 2020 and January 2024. This area lies between the Macquarie River and Marra Creek and is drained by Ginghet and Marra Creeks and smaller channels, which bisect palaeochannels, sandplains and swamps dominated by E. largiflorens and E. populnea. Almost 65% of host trees were E. populnea, and the remainder mostly E. largiflorens, with three E. coolabah and four C. cristata hosts. Most epiphytes were G. parviflora (51%), followed by E. saligna (15%); the other 16 species had between one and 17 representatives (Table 2). With the exception of spiny fan-flower (Scaevola spinescens) and Ellangowan poison bush (Eremophila deserti), all were also recorded as epiphytes in the Barwon palaeochannels.

Twenty-seven epiphytes were found in the area immediately surrounding but outside of the Barwon palaeochannels, roughly bounded by Thallon in Queensland, Lightning Ridge and Narran Lake, all growing in E. populnea (Fig. 1; Table 2). Clusters were found around the permanent Cumborah Springs to the north-west of Gingie (17 small–medium epiphytes in an area of ~8 km²) and on a low, stony rise above the Moonie River just north-east of the Barwon palaeochannels (eight small–medium epiphytes in an area of 0.25 km²). Both areas were characterised by multi-trunked E. populnea with extensive anthropogenic modification (both pre- and post-contact, including cut branches and historical ringbarking).

In other areas, epiphytes were found as isolated specimens or in localised clusters, either seen from a vehicle or found during targeted foot searches. All of the remaining 67 epiphytes were found on alluvial levees, plains or swamps associated with major drainage systems including the Moonie, Balonne, Castlereagh, Maranoa, Warrego, Paroo and McIntyre Rivers, except for a small Eremophila longifolia growing in a silver-leaf ironbark (Eucalyptus melanophloia) on a low, spinifex-dominated sand dune and a G. parviflora growing in an E. populnea hollow on a red earth plain, both near Charleville, and three epiphytes (two Brachychiton rupestris and an Archidendropsis basaltica) growing in E. populnea hollows on a mulga-dominated tableland of the Enniskillen Range south-west of Blackall (Fig. 1). The largest concentrations were found in an area of 2.9 km² south of the Castlereagh River on the Cumbadoon Way, where 18 epiphytes (mostly wilgas) were found in poplar boxes, and in an area of 0.04 km² south of St George adjacent to the Balonne River, where nine sally wattles (Acacia salicina) were found growing in E. populnea trees that had been ringbarked and resprouted, creating a central crotch for the seedlings to establish and grow. Nine additional species (i.e. not documented in the Barwon palaeochannels) were recorded as epiphytes (Table 2). All except nine host trees were E. populnea, and 54% of host hollows were anthropogenically created. Most epiphytes measured were small or medium, with just seven having a DBH >15 cm including two huge A. salicina near Dunkeld on the Maranoa River and three A. oleifolius, two near Charleville and one on the Moonie River at Nindigully.

Epiphyte presence at search sites where habitat variables were recorded (n = 79) was positively correlated with density of Indigenous Culturally Modified Trees (P = 0.013), density of post-colonial (European) modified trees (P = 0.007) and total number of potential hollows seen (P = 0.002). The two former variables were also positively correlated with each other (P = 0.008). Mean annual rainfall was weakly negatively correlated with epiphyte presence (P = 0.027), probably reflecting the fact that most epiphytes were found in the Barwon palaeochannels area, where average rainfall is 420–440 mm per annum, and were rarely found in the lower and higher rainfall areas to the north-west and north-east of this area (Figs 1 and 4). The number of potential epiphytes present at a site was higher where epiphytes were found (Fig. 4), but this was only significant on its own and was not a good predictor within the model based on the AIC.

Fig. 4.

Boxplots showing habitat variables as related to epiphyte presence and absence at survey sites in northern New South Wales and southern Queensland (n = 79). CMTs, Culturally Modified Trees. ‘Potential hollows’ describes sites within trees that could potentially host epiphytes. Potential epiphyte species include all those recorded growing epiphytically in the study area.

The eight species commonly recorded as epiphytes occur widely across inland eastern Australia, and many extend into other areas of arid and semi-arid Australia (Fig. 5). In total, 30 mapped REs in Queensland and 14 Plant Community Types (PCT) in New South Wales are dominated by E. populnea, and five by the closely related E. brownii. Twenty-nine REs and five PCTs are dominated by E. coolabah, and two REs and eight PCTs by E. largiflorens. Most of the extensive E. coolabah-dominated ecosystems occur in more arid regions and do not overlap with high concentrations of potential epiphytic species. Large areas of E. populnea and E. largiflorens occur in central and southern Queensland and central-western New South Wales and overlap with numerous potential epiphyte species (Fig. 5).

Fig. 5.

Specimen collection records (AVH 2023) of the eight species with at least 20 recorded epiphytic occurrences in this study. Ehretia saligna and Geijera parviflora, the two most common epiphytes, are represented by black dots; other species (Alectryon oleifolium, Alstonia constricta, Apophyllum anomalum, Atalaya hemiglauca, Capparis mitchellii, Eremophila mitchellii, Ventilago viminalis) by white dots. Eucalyptus populnea and E. brownii-dominated Regional Ecosystems/Plant Community Types are shaded dark grey; E. coolabah and E. largiflorens are shaded light grey. The 500-mm isohyet delineating the semi-arid zone is shown as a dashed line. Green triangles indicate epiphytes recorded during this study; red crosses show areas searched with no epiphytes found.

Of the 15 ecologists and land managers interviewed, three were able to provide photos and details of woody epiphytes. One of these epiphytes (a Brachychiton populneus growing in an E. populnea) occurs near the Langlo River in south-west Queensland (Chris Crafter, pers. comm. March 2022), and is included in the results presented here. Also reported were a C. glaucophylla growing in an E. camaldulensis in the Flinders Ranges (Mike Bremers, pers. comm., June 2022), and a Banksia marginata in an E. camaldulensis in western Victoria (Attila Kapitany, pers. comm., November 2011). Two other respondents stated that they may have observed this phenomenon but could not provide a specific example with a location, whereas the remaining 10 respondents stated that they had not observed epiphytic occurrences of woody species in semi-arid or arid areas.