Appendix 1. List of plants restricted to the western Arnhem Land plateau (±30- km buffer) ***entirely within 5-km buffer, **entirely within 10-km buffer, *entirely within 20- km buffer Scientific name Family No. of Buffer records Acacia amanda MIMOSACEAE 8 *** Acacia brockii MIMOSACEAE 20 *** Acacia filipes MIMOSACEAE 6 Acacia gracilenta MIMOSACEAE 13 ** Acacia sp. laterite (I.D.Cowie 8754) MIMOSACEAE 5 *** Acacia malloclada MIMOSACEAE 4 Acacia multistipulosa MIMOSACEAE 20 ** Acacia proiantha MIMOSACEAE 8 Acacia rigescens MIMOSACEAE 3 *** Acacia scopulorum MIMOSACEAE 37 Acomis kakadu ASTERACEAE 9 *** Allosyncarpia ternata MYRTACEAE 254 Alyxia evansii APOCYNACEAE 1 *** Amyema tridactyla LORANTHACEAE 19 Boronia amplectens RUTACEAE 1 *** Boronia laxa RUTACEAE 19 *** Boronia prolixa RUTACEAE 17 *** Boronia quadrilata RUTACEAE 1 *** Boronia rupicola RUTACEAE 5 *** Boronia suberosa RUTACEAE 4 *** Boronia tolerans RUTACEAE 5 *** Boronia verecunda RUTACEAE 10 *** Boronia viridiflora RUTACEAE 1 *** Boronia xanthastrum RUTACEAE 9 Cajanus aromaticus FABACEAE 25 * Calytrix decussata MYRTACEAE 41 * Calytrix faucicola MYRTACEAE 23 * Calytrix inopinata MYRTACEAE 3 *** Calytrix micrairoides MYRTACEAE 14 * Calytrix rupestris MYRTACEAE 8 *** Calytrix surdiviperana MYRTACEAE 12 *** Clausospicula extensa POACEAE 8 * Corchorus aulacocarpus TILIACEAE 3 *** Corchorus macropterus TILIACEAE 12 *** Corchorus sublatus TILIACEAE 9 * Corymbia oocarpa MYRTACEAE 19 * Cryptandra sp. Jabiru (L.A.Craven 6484) RHAMNACEAE 5 *** Cryptandra gemmata RHAMNACEAE 7 * Cycas arenicola CYCADACEAE 13 *** Cyperus sp. Edith River (M.Lazarides 124) CYPERACEAE 8 * Dicarpidium sp. Katherine Gorge (C.R.Dunlop 5225) STERCULIACEAE 20 *** Duboisia arenitensis SOLANACEAE 1 *** Dubouzetia australiensis ELAEOCARPACEAE 12 *** Eriachne axillaris POACEAE 6 Eucalyptus gigantangion MYRTACEAE 24 * Eucalyptus glomericassis MYRTACEAE 33 Eucalyptus koolpinensis MYRTACEAE 24 *** Fimbristylis arnhemensis CYPERACEAE 17 *** Fimbristylis sp. Mount Brockman (R.C.Hinz 362) CYPERACEAE 5 *** Gardenia jabiluka RUBIACEAE 3 *** Gardenia kakaduensis RUBIACEAE 20 Glinus sessiliflorus MOLLUGINACEAE 4 * Goodenia cirrifica GOODENIACEAE 60 * Goodenia potamica GOODENIACEAE 5 Grevillea aurea PROTEACEAE 21 *** Grevillea brevis PROTEACEAE 17 *** Grevillea dunlopii PROTEACEAE 10 * Grevillea formosa PROTEACEAE 26 * Grevillea glabrescens PROTEACEAE 13 ** Grevillea polyacida PROTEACEAE 20 * Grevillea rubicunda PROTEACEAE 11 *** Grevillea versicolor PROTEACEAE 8 *** Gynochthodes australiensis RUBIACEAE 170 * Helicteres sp. Kakadu (L.G.Adams 3089) STERCULIACEAE 36 ** Heliotropium amnis-edith BORAGINACEAE 3 Hibbertia arnhemica DILLENIACEAE 18 Hibbertia sp. Marrawal (K.G.Brennan 3194) DILLENIACEAE 4 *** Hibbertia sp. Mount Howship (C.R.Dunlop 6656) DILLENIACEAE 8 *** Hibiscus aneuthe MALVACEAE 3 *** Hibiscus brennanii MALVACEAE 4 *** Hibiscus byrnesii MALVACEAE 23 * Hibiscus inimicus MALVACEAE 6 *** Hibiscus menzeliae MALVACEAE 20 *** Hibiscus riceae MALVACEAE 5 *** Hibiscus symonii MALVACEAE 26 ** Hibiscus thegaleus MALVACEAE 1 Hildegardia australiensis STERCULIACEAE 12 *** Indigofera verruculosa FABACEAE 8 *** Jacksonia sp. bifida (K.G.Brennan 599) FABACEAE 3 *** Jacksonia sp. flexuosa (K.G.Brennan 2364) FABACEAE 2 *** Jacksonia sp. pendens (L.A.Craven 5990) FABACEAE 13 Jacksonia sp. stellaris (N.B.Byrnes 1787) FABACEAE 12 *** Lechenaultia ovata GOODENIACEAE 9 *** Lindernia sp. dissected leaf ((N.B.Byrnes 1520) SCROPHULARIACEAE 12 ** Lithomyrtus cordata MYRTACEAE 45 * Lithomyrtus grandifolia MYRTACEAE 20 Lithomyrtus kakaduensis MYRTACEAE 22 ** Lithomyrtus linariifolia MYRTACEAE 13 * Lithomyrtus repens MYRTACEAE 30 Lophopetalum arnhemicum CELASTRACEAE 106 Melaleuca cornucopiae MYRTACEAE 37 * Melaleuca stipitata MYRTACEAE 6 *** Melodorum rupestre ANNONACEAE 112 Memecylon arnhemensis MELASTOMATACEAE 10 *** Micraira compacta POACEAE 10 *** Micraira dentata POACEAE 5 *** Micraira inserta POACEAE 3 *** Micraira multinervia POACEAE 6 *** Micraira pungens POACEAE 10 *** Micraira spinifera POACEAE 4 * Micraira subspicata POACEAE 10 * Micraira tenuis POACEAE 34 * Micraira viscidula POACEAE 9 *** Microcorys elliptica LAMIACEAE 5 *** Mitrasacme floribunda LOGANIACEAE 15 *** Mitrasacme geniculosa LOGANIACEAE 3 * Mitrasacme troglodytica LOGANIACEAE 1 *** Mukia sp. Gunlom (J.L.McKean 864b) CUCURBITACEAE 25 ** Neobyrnesia suberosa RUTACEAE 20 ** Nymphoides planosperma MENYANTHACEAE 5 *** Ochrosperma sulcatum MYRTACEAE 5 *** Oldenlandia intonsa RUBIACEAE 2 *** Oldenlandia thysanota RUBIACEAE 39

1 Pachynema hooglandii DILLENIACEAE 18 * Pachynema praestans DILLENIACEAE 33 * Petraeomyrtus punicea MYRTACEAE 36 *** Phoringopsis byrnesii ORCHIDACEAE 8 *** Phyllanthus cauticola EUPHORBIACEAE 2 *** Pityrodia byrnesii VERBENACEAE 6 *** Pityrodia gilruthiana VERBENACEAE 20 *** Pityrodia lanceolata VERBENACEAE 33 Pityrodia megalophylla VERBENACEAE 4 Pityrodia puberula VERBENACEAE 10 *** Pityrodia pungens VERBENACEAE 29 * Pityrodia serrata VERBENACEAE 6 *** Pityrodia spenceri VERBENACEAE 11 Platysace arnhemica APIACEAE 26 * Polycarpaea incana CARYOPHYLLACEAE 15 Polycarpaea microceps CARYOPHYLLACEAE 17 ** Polycarpaea tenax CARYOPHYLLACEAE 13 * Ptilotus rotundatus AMARANTHACEAE 4 ** Rhynchospora sp. Arnhem (P.K.Latz 2999) CYPERACEAE 28 Sauropus dunlopii EUPHORBIACEAE 12 *** Sauropus filicinus EUPHORBIACEAE 7 *** Sauropus gracilis EUPHORBIACEAE 1 *** Sauropus rimophilus EUPHORBIACEAE 16 *** Schoenus sp. Deaf Adder Gorge (C.R.Dunlop 4444) CYPERACEAE 11 *** Scleria sp. Jabiru (L.A.Craven 6342) CYPERACEAE 23 *** Simaroubaceae sp. Mary River (I.D.Cowie 1454) SIMAROUBACEAE 6 *** Solanum asymmetriphyllum SOLANACEAE 44 ** Spermacoce brevidens RUBIACEAE 6 *** Spermacoce cardiophora RUBIACEAE 1 *** Spermacoce caudata RUBIACEAE 6 *** Spermacoce congestanthera RUBIACEAE 12 ** Spermacoce discreta RUBIACEAE 7 *** Spermacoce diversistyla RUBIACEAE 12 ** Spermacoce erectiloba RUBIACEAE 48 Spermacoce erosa RUBIACEAE 5 * Spermacoce lamprosperma RUBIACEAE 6 * Spermacoce parviceps RUBIACEAE 2 *** Spermacoce reticulata RUBIACEAE 12 ** Spermacoce tectanthera RUBIACEAE 1 *** Spermacoce trichosiphonia RUBIACEAE 6 *** Stylidium accedens STYLIDIACEAE 8 *** Stylidium divergens STYLIDIACEAE 2 *** Stylidium simulans STYLIDIACEAE 4 *** Symplectrodia gracilis POACEAE 4 *** Symplectrodia lanosa POACEAE 27 *** Syzygium arenitense MYRTACEAE 9 *** Tephrosia humifusa FABACEAE 7 Tephrosia sp. conduplicate (B.L.Rice 3139) FABACEAE 13 Thecanthes filifolia THYMELAEACEAE 38 Toechima sp. East Alligator (J.Russell-Smith 8418) SAPINDACEAE 3 *** Triodia aristiglumis POACEAE 2 *** Triodia aurita POACEAE 1 *** Triodia contorta POACEAE 9 *** Triodia radonensis POACEAE 2 *** Triodia uniaristata POACEAE 6 *** Triumfetta oenpelliensis TILIACEAE 2 *** Utricularia arnhemica LENTIBULARIACEAE 40 * Utricularia cheiranthos LENTIBULARIACEAE 6 * Utricularia rhododactylos LENTIBULARIACEAE 4 ***

2 Appendix 2. List of plants with 90–99.9% of their distribution restricted to the western Arnhem Land plateau (±30-km buffer) Scientific name Family No. of records Arnhem Land Northern plateau Territory Acacia convallium MIMOSACEAE 34 38 Acacia echinuliflora MIMOSACEAE 17 18 Acacia lacertensis MIMOSACEAE 34 36 Acacia linarioides MIMOSACEAE 42 45 Acacia sericoflora MIMOSACEAE 45 48 Arthrochilus latipes ORCHIDACEAE 29 31 Asteromyrtus magnifica MYRTACEAE 62 66 Calytrix megaphylla MYRTACEAE 37 41 Corymbia arnhemensis MYRTACEAE 110 111 Croton byrnesii EUPHORBIACEAE 44 49 Eriachne compacta POACEAE 28 29 Fimbristylis composita CYPERACEAE 177 187 Gardenia faucicola RUBIACEAE 55 56 Hibiscus arnhemensis MALVACEAE 29 32 Labichea saxicola CAESALPINIACEAE 31 32 Lithomyrtus densifolia MYRTACEAE 23 25 Merremia sp. Kakadu (C.R.Dunlop 5659) CONVOLVULACEAE 28 30 Micraira adamsii POACEAE 46 47 Nymphoides furculifolia MENYANTHACEAE 39 40 Pityrodia jamesii VERBENACEAE 33 35 Pityrodia quadrangulata VERBENACEAE 35 37 Spermacoce aurantiseta RUBIACEAE 15 16 Thryptomene remota MYRTACEAE 47 49 Triodia plectrachnoides POACEAE 66 77 Verticordia decussata MYRTACEAE 40 43

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