Flora of the Houtman Abrolhos

This is a list of the terrestrial flora of the Houtman Abrolhos. Only vascular plants are listed — there have been some collections of mosses, liverworts and lichens from the Houtman Abrolhos, but no information has been published on these non-vascular groups.[1]

The distribution of each species within each island group is provided. A list of islands is provided for species that occur on fewer than ten islands in a group; for species that occur on ten or more islands in a group, an island count is provided. Islands without a formally gazetted name are referred to by informal names, given in quotation marks.

A grey background indicates a naturalised species.

Scientific name	Common name	Distribution			Remarks	Image
		Wallabi Group (45 islands)	Easter Group (34 islands)	Pelsaert Group (41 islands)
Aizoaceae
Carpobrotus sp.			Rat I.
Carpobrotus virescens	Coastal Pigface	13 islands	25 islands	23 islands
Disphyma crassifolium subsp. clavellatum	Round-leaved Pigface	Pigeon I.	Leo I., Rat I.
Mesembryanthemum crystallinum	Iceplant	40 islands	18 islands	30 islands	Naturalised
Sesuvium portulacastrum			Campbell I.
Tetragonia decumbens	Sea Spinach		Crake I., Keru I., White I., Wooded I.		Naturalised
Amaranthaceae
Ptilotus divaricatus	Climbing Mulla Mulla	East Wallabi I.
Ptilotus eriotrichus		East Wallabi I., West Wallabi I.
Ptilotus gaudichaudii		East Wallabi I.	Serventy I.
Ptilotus obovatus	Cotton Bush	East Wallabi I.
Ptilotus villosiflorus		West Wallabi I.
Anthericaceae
Thysanotus patersonii		East Wallabi I., North I., Pigeon I., Seagull I., West Wallabi I.
Apiaceae
Apium annuum		East Wallabi I., West Wallabi I.	Alexander I., Campbell I., Serventy I.
Apium prostratum	Sea Celery	Tattler I.		Middle I.
Daucus glochidiatus	Australian Carrot	East Wallabi I., North I., Pigeon I., West Wallabi I.	Campbell I., Keru I., White I.	Middle I.
Hydrocotyle diantha		East Wallabi I., West Wallabi I.	Rat I.	Basile I., Middle I.
Petroselinum crispum	Parsley		Little Rat I., Rat I., Roma I.		Naturalised
Trachymene pilosa	Native Parsnip	East Wallabi I.
Apocynaceae
Alyxia buxifolia	Dysentery Bush	East Wallabi I., Seagull I. and West Wallabi I.
Asclepiadaceae
Sarcostemma viminale subsp. australe		"Eagle Point Islet", East Wallabi I., Oystercatcher I., Pigeon I., Seagull I. and West Wallabi I.		Basile I., Middle I.
Asphodelaceae
Bulbine semibarbata	Leek Lily	"Eagle Point Islet", East Wallabi I., Little Pigeon I., North I., Pigeon I. and West Wallabi I.	Rat I.	Middle I., Pelsaert I.
Asteraceae
Actinobole condensatum		East Wallabi I., North I., West Wallabi I.
Actites megalocarpa	Dune Thistle	Little Pigeon I., Long I., Oystercatcher I., Pigeon I., Seagull I.		Pelsaert I.
Angianthus tomentosus	Camel-grass	East Wallabi I.
Brachyscome ciliaris		East Wallabi I., North I., Pigeon I.	Little Rat I.
Brachyscome iberidifolia		East Wallabi I.
Calocephalus aervoides	Woolly Beauty-heads	East Wallabi I., West Wallabi I.			Rated "Priority Three - Poorly Known Taxa" in the Department of Environment and Conservation's Declared Rare and Priority Flora List.[2]
Chthonocephalus tomentellus		West Wallabi I.			Rated "Priority Two - Poorly Known Taxa" in the Department of Environment and Conservation's Declared Rare and Priority Flora List.[3]
Conyza bonariensis	Flaxleaf Fleabane	Little Pigeon I., Pigeon I.	Bushby I., Little Rat I., Rat I., Roma I.		Naturalised
Conyza sumatrensis	Tall Fleabane		Rat I.		Naturalised. Harvey et al. (2001) lists C. albida, but this is now a taxonomic synonym of C. sumatrensis.[4]
Erigeron karvinskianus				Gun I., Murray I.	Naturalised
Euchiton sphaericus		East Wallabi I., North I.	Rat I.
Gnaphalium indutum	Tiny Cudweed	East Wallabi I.	Leo I.
Helichrysum luteoalbum	Jersey Cudweed	East Wallabi I., North I., Turnstone I., West Wallabi I.	Little Rat I., Rat I.		Naturalised. Harvey et al. (2001) lists Pseudognaphalium luteoalbum, but this is now a nomenclatural synonym of Helichrysum luteoalbum.[5]
Hypochaeris glabra	Smooth Catsear			Basile I.	Naturalised
Lactuca saligna	Wild Lettuce	Pigeon I.			Naturalised
Olearia axillaris	Coastal Daisybush	Eastern I., East Wallabi I., Long I., North I., Pigeon I., Turnstone I., West Wallabi I.	Campbell I.
Podotheca angustifolia	Sticky Longheads	North I., West Wallabi I.
Reichardia tingitana	False Sowthistle		Campbell I., Rat I.	Basile I., Middle I.	Naturalised
Senecio glossanthus	Slender Groundsel	East Wallabi I., North I., West Wallabi I.
Senecio pinnatifolius		23 islands	17 islands	16 islands	Harvey et al. (2001) lists S. lautus but this name has been misapplied in Western Australia to S. pinnatifolius.[6]
Sonchus oleraceus	Common Sowthistle	20 islands	19 islands	16 islands	Naturalised. Harvey et al. (2001) lists both S. oleraceus and S. tenerrimus on four islands, and S. tenerrimus alone on another. However, the latter name is now considered a misapplication against the former in Western Australia,[7] so here the entries for these names have been pooled.
Urospermum picroides	False Hawkbit	10 islands	10 islands	Burnett Rock, Burton I., Gun I., Post Office I., Uncle Margie I.	Naturalised
Ursinia anthemoides	Ursinia		Alexander I., Leo I., Serventy I., White I.	Burnett Rock, Burton I.	Naturalised.
Vittadinia cuneata var. cuneata	Woolly Vittadinia	Akerstrom I., Barge Rock, East Wallabi I., Marinula I., Seagull I., Turnstone I.
Vittadinia sp.		East Wallabi I.
Avicenniaceae
Avicennia marina	White Mangrove	Akerstrom I., "East Mangrove I.", Marinula I., Oystercatcher I., Seagull I., Tattler I., Turnstone I., West Wallabi I.	Alexander I., Campbell I., Keru I., Little Rat I., "Little Stokes I.", Morley I., Serventy I., Suomi I., Wooded I.	14 islands
Boraginaceae
Cynoglossum australe	Australian Hound's-tongue	East Wallabi I., West Wallabi I.			Harvey et al. (2001) lists this species, but according to FloraBase it does not occur in Western Australia.[8]
Echium plantagineum	Paterson's Curse	East Wallabi I.			Naturalised; classed as a noxious weed.[9]
Trichodesma zeylanicum	Camel Bush	North I.
Brassicaceae
Brassica rapa		Beacon I.			Naturalised
Cakile maritima	Sea Rocket	10 islands	13 islands	12 islands	Naturalised
Hornungia procumbens	Oval Purse	14 islands	Bynoe I., Leo I., Morley I., Serventy I.	Burton I., Pelsaert I.	Naturalised. Harvey et al. (2001) lists Hornungia procumbens on 13 islands, and Hymenolobus procumbens on another, but the latter name is now considered a synonym of the former.[10]
Lepidium lyratogynum		Eastern I.	Bynoe I., Leo I., Little North I., White I.
Lepidium pseudoruderale		Beacon I., Dakin I., Dick I., Eastern I., Saville-Kent I., Seal I.		Burnett Rock, Burton I., Coronation I., Jackson I., "Little Jackson I.", Newman I., Pelsaert I., Post Office I., Square I.
Lepidium puberulum		Eastern I., "First Sister Islet"	10 islands		Rated "Priority Four — Rare Taxa" in the Department of Environment and Conservation's system of Declared Rare and Priority Flora List.[11]
Raphanus raphanistrum	Wild radish	Pigeon I.	Alexander I., Little Rat I., Rat I., Serventy I.	Basile I., Gun I., Murray I., Pelsaert I., Post Office I.	Naturalised
Raphanus sativus	Radish		Alexander I.	Basile I., Burnett Rock	Naturalised
Sisymbrium irio	London Rocket		Suomi I.		Naturalised
Sisymbrium orientale	Indian Hedge Mustard	Beacon I.	Little Rat I., Rat I.	Burnett Rock	Naturalised
Cactaceae
Opuntia stricta	Common Prickly Pear		Rat I.	Basile I.	Naturalised
Campanulaceae
Wahlenbergia gracilis			Rat I.
Wahlenbergia multicaulis			Rat I.
Capparaceae
Capparis spinosa	Coastal Caper	"Eagle Point Islet", East Wallabi I., Little Pigeon I., Oystercatcher I., Pigeon I., Seagull I., Tattler I., Turnstone I., West Wallabi I.
Caryophyllaceae
Cerastium glomeratum	Mouse Ear Chickweed			Eight I., Three I.	Naturalised
Petrorhagia dubia	Velvet Pink		Rat I.		Naturalised. Harvey et al. (2001) lists P. velutina, but this is now a taxonomic synonym of P. dubia.[12]
Polycarpon tetraphyllum	Fourleaf Allseed	East Wallabi I., Little Pigeon I., Pigeon I.	Little Roma I.	Basile I., Jackson I.	Naturalised
Sagina apetala	Annual Pearlwort	East Wallabi I.			Naturalised
Silene gallica	French Catchfly		White I.		Naturalised
Silene nocturna	Mediterranean Catchfly		Alexander I., Bynoe I., Little Rat I., Morley I., Serventy I.		Naturalised
Spergularia diandra	Lesser Sand Spurry			Gun I.	Naturalised
Spergularia rubra	Sand Spurry	12 islands	Little Rat I., Roma I.	Pelsaert I., Three I.	Naturalised
Spergularia sp. 5 Leeman			Rat I.		Harvey et al. (2001) lists S. nesophila, but this is an unpublished manuscript name, which is considered a nomenclatural synonym of the above.[13]
Stellaria media	Chickweed	West Wallabi I.			Naturalised
Celastraceae
Stackhousia sp.		West Wallabi I.			Harvey et al. (2001) lists this under Stackhousiaceae, but it is now generally treated under Celastraceae.[14]
Stackhousia sp.		East Wallabi I., North I., West Wallabi I.			Harvey et al. (2001) lists this as Stackhousia viminea, but this name has been misapplied in Western Australia against three species: S. clementii, S. muricata and S. intermedia.[15] Harvey et al. (2001) treats Stackhousia under Stackhousiaceae, but it is now generally treated under Celastraceae.[14]
Tripterococcus brunonis		East Wallabi I.			Harvey et al. (2001) lists this under Stackhousiaceae, but it is now generally treated under Celastraceae.[14]
Chenopodiaceae
Atriplex amnicola	Swamp Saltbush			Gun I., Murray I., Pelsaert I.
Atriplex bunburyana	Silver Saltbush		Rat I.
Atriplex cinerea	Grey Saltbush	27 islands	21 islands	22 islands
Atriplex paludosa	Marsh Saltbush	Little Pigeon I., Long I., Mangrove I., North I., Pelican I., Pigeon I., Tattler I., West Wallabi I.
Atriplex paludosa subsp. baudinii			Rat I.
Atriplex vesicaria subsp. variabilis	Bladder Saltbush	Seagull I.
Atriplex sp.	Saltbush	17 islands	10 islands	18 islands
Chenopodium album	Fat Hen		Rat I.		Naturalised
Chenopodium melanocarpum	Black Crumbweed	East Wallabi I.
Chenopodium murale	Nettle-leaf Goosefoot	Beacon I., North I., Pelican I., West Wallabi I.	Alexander I., Joe Smith I., "Landscope I.", "Nitraria I.", Rat I., Wooded I.	Burton I., Gun I., "Little Jackson I.", Pelsaert I., Square I., Uncle Margie I.	Naturalised
Chenopodium nitrariaceum	Nitre Goosefoot	East Wallabi I., West Wallabi I.
Dysphania plantaginella		East Wallabi I.
Enchylaena tomentosa	Barrier Saltbush	26 islands	11 islands	17 islands
Rhagodia baccata	Berry Saltbush	Akerstrom I., East Wallabi I., North I., Oystercatcher I., Pigeon I., Seagull I., Tattler I., Turnstone I., West Wallabi I.
Rhagodia latifolia		Akerstrom I., "Eagle Point Islet", Little Pigeon I., North I., Pigeon I.
Rhagodia preissii subsp. obovata			Little Rat I., Rat I.
Rhagodia sp.			Rat I.
Salsola kali	Prickly Saltwort	Dick I., Eastern I., East Wallabi I., Long I., North I., Seal I., Third Sister, West Wallabi I.	Bynoe I., Campbell I., Crake I., Leo I., Morley I., Rat I.	Basile I., Coronation I., Pelsaert I., Stick I.	Naturalised
Sarcocornia quinqueflora	Beaded Samphire	17 islands	19 islands	15 islands
Suaeda australis	Seablite	11 islands	"Nitraria I.", Tapani I., Wooded I.	Newman I., Pelsaert I.
Tecticornia arbuscula		East Wallabi I., North I., Pigeon I., West Wallabi I.		Gun I., Middle I., Murray I., Pelsaert I.	Harvey et al. (2001) listed Sclerostegia arbuscula, but all Sclerostegia were transferred into Tecticornia in 2007.[16]
Tecticornia halocnemoides	Shrubby Samphire	Akerstrom I., Alcatraz I., Barge Rock, East Wallabi I., North I., Pigeon I., Shag Rock, West Wallabi I.	13 islands	25 islands	Harvey et al. (2001) listed Halosarcia halocnemoides, but all Halosarcia were transferred into Tecticornia in 2007.[16]
Tecticornia lepidosperma subsp. bidens		Akerstrom I.	Little Rat I., Rat I.	Lagoon I., Pelsaert I.	Harvey et al. (2001) listed Halosarcia indica subsp. bidens, but all Halosarcia were transferred into Tecticornia in 2007.[16]
Tecticornia sp.	Samphire	West Wallabi I.			Harvey et al. (2001) listed Halosarcia sp., but all Halosarcia were transferred to Tecticornia in 2007.[16]
Threlkeldia diffusa	Coast Bonefruit	33 islands	19 islands	20 islands
Colchicaceae
Wurmbea monantha		East Wallabi I., North I., West Wallabi I.	Alexander I., Serventy I.
Convolvulaceae
Ipomoea cairica			Little Rat I.		Naturalised
Crassulaceae
Bryophyllum delagoense	Mother of Millions	Pigeon I.	Rat I.		Naturalised. In 2000 this poisonous weed was found to have colonised over half of Rat and Pigeon Islands.[17]
Crassula colorata	Dense Stonecrop	Dick I., Eastern I., East Wallabi I., Long I., North I., Tattler I., West Wallabi I.	10 islands	Basile I., Burton I., Middle I., Pelsaert I., Stick I.
Crassula exserta			Bynoe I., Campbell I., Leo I., White I.
Cotyledon orbiculata		Dick I., Eastern I., Pigeon I., West Wallabi I.
Cucurbitaceae
Cucurbita pepo			Rat I.
Cunoniaceae
Aphanopetalum clematideum		East Wallabi I.
Cyperaceae
Ficinia nodosa	Knotted Club Rush	North I.			Harvey et al. (2001) listed Isolepis nodosa, but this species has since been transferred into Ficinia.[18]
Isolepis marginata	Coarse Clubrush	East Wallabi I., West Wallabi I.			Naturalised
Dasypogonaceae
Acanthocarpus preissii		"Eagle Point Islet", East Wallabi I., Little Pigeon I., North I., Oystercatcher I., Pigeon I., Seagull I., Tattler I., West Wallabi I.
Dilleniaceae
Hibbertia racemosa	Stalked Guinea Flower	East Wallabi I., West Wallabi I.
Epacridaceae
Leucopogon insularis		East Wallabi I., West Wallabi I.
Euphorbiaceae
Beyeria viscosa	Pinkwood	East Wallabi I., Oystercatcher I., West Wallabi I.
Euphorbia boophthona	Gascoyne Spurge	Pigeon I.
Euphorbia drummondii	Caustic Weed	East Wallabi I., West Wallabi I.	Little Rat I., Rat I.	Middle I.
Euphorbia tannensis		"Eagle Point Islet", Little Pigeon I., North I., Oystercatcher I., Pigeon I., Seagull I., Turnstone I.		Middle I.
Euphorbia terracina	Geraldton Carnation Weed	Pigeon I.	Little Rat I., Rat I.		Naturalised
Phyllanthus calycinus	False Boronia	East Wallabi I., West Wallabi I.
Frankeniaceae
Frankenia pauciflora	Seaheath	11 islands	Bushby I., Campbell I., Little Rat I., Rat I.	Davis I., Gun I., Middle I., Murray I., Pelsaert I., Sweet I.
Gentianaceae
Centaurium erythraea	Common Centaury		Bushby I., Little Rat I.		Naturalised
Schenkia australis		East Wallabi I., North I., Pigeon I., Tattler I., Turnstone I., West Wallabi I.		Basile I., Gun I., Pelsaert I.	Naturalised. Harvey et al. (2001) lists this as Centaurium spicatum, but this species has been transferred into Schenkia, and the Australian specimens segregated into a new species as S. australis. Harvey et al. (2001) also lists C. maritimum on East Wallabi Island, but this name has been misapplied for C. spicatum in Australia.[19]
Geraniaceae
Erodium cicutarium	Common Storksbill	Barge Rock, East Wallabi I., Long I., North I., Pigeon I., West Wallabi I.	Little Rat I., Rat I.	Middle I., Pelsaert I., Square I.	Naturalised
Erodium cygnorum	Blue Heronsbill	East Wallabi I., North I., Pigeon I.
Pelargonium littorale		East Wallabi I.
Pelargonium zonale			Rat I.		Naturalised. Harvey et al. (2001) lists this species, but FloraBase has no record of it occurring in Western Australia.[20]
Goodeniaceae
Scaevola crassifolia	Thick-leaved Fan-flower	East Wallabi I., North I., Seagull I., West Wallabi I.	Campbell I., Rat I., Suomi I.	Pelsaert I.
Haloragaceae
Haloragis trigonocarpa		East Wallabi I., Pigeon I.
Juncaceae
Juncus bufonius	Toad Rush	East Wallabi I., North I., Pigeon I., West Wallabi I.			Naturalised
Juncaginaceae
Triglochin centrocarpa		Dick I., Pigeon I., West Wallabi I.		Gun I., Middle I., Pelsaert I., Three I.
Triglochin mucronata		North I., West Wallabi I.
Triglochin muelleri		East Wallabi I.
Triglochin trichophora		Barge Rock, East Wallabi I., North I.	Keru I., Rat I., Serventy I.
Lamiaceae
Westringia dampieri		East Wallabi I., First Sister, West Wallabi I.
Liliaceae
Aloe sp.		Little Pigeon I.			Naturalised
Loganiaceae
Phyllangium paradoxum		West Wallabi I.
Malvaceae
Lavatera sp.			"Shearwater Islet"
Malva preissiana	Australian Hollyhock	21 islands	15 islands	12 islands	Harvey et al. (2001) lists this as Lavatera plebeia, but this is now a synonym of M. preissiana.[21]
Malva linnaei	Cretan Mallow		Little North I., White I.		Naturalised according to FloraBase, though not according to Harvey et al. (2001).[22] The latter source lists this as Lavatera cretica, but this is now a synonym of M. linnaei.[23]
Malva parviflora	Marshmallow	East Wallabi I., North I., Pigeon I., West Wallabi I.	Rat I.	Newman I., Sid Liddon I.	Naturalised
Sida spodochroma		East Wallabi I.
Mimosaceae
Acacia didyma		East Wallabi I.
Myoporaceae
Eremophila glabra	Tar Bush	East Wallabi I., West Wallabi I.		Basile I., Middle I.
Eremophila deserti		East Wallabi I.
Myoporum insulare	Blueberry Tree	27 islands	22 islands	17 islands
Myrtaceae
Eucalyptus oraria	Ooragmandee	East Wallabi I.
Onagraceae
Epilobium billardiereanum	Glabrous Willow Herb	East Wallabi I.
Orobanchaceae
Orobanche minor	Lesser Broomrape	East Wallabi I.			Naturalised
Orchidaceae
Microtis media	Tall Mignonette Orchid	East Wallabi I.
Microtis sp.		East Wallabi I.
Oxalidaceae
Oxalis corniculata	Yellow Wood Sorrel	East Wallabi I., West Wallabi I.			Naturalised
Papilionaceae
Bossiaea spinescens		East Wallabi I.
Medicago polymorpha	Burr Medic	Little Pigeon I., Pigeon I.	Little Rat I., Rat I., Suomi I.	Pelsaert I.	Naturalised
Medicago sp.			Rat I.		Naturalised
Melilotus indicus		Beacon I., North I.	Bushby I., Little Rat I., Rat I.	Basile I., Gun I., Pelsaert I., Post Office I.	Naturalised
Mirbelia ramulosa		East Wallabi I.
Phormiaceae
Dianella revoluta	Blueberry Lily	"Eagle Point Islet", East Wallabi I., Oystercatcher I., Pigeon I., Seagull I., Tattler I., West Wallabi I.
Pittosporaceae
Pittosporum phillyreoides	Weeping Pittosporum	10 islands		Middle I.
Plantaginaceae
Plantago coronopus	Buckshorn Plantain		Little Rat I.
Plantago debilis		East Wallabi I., North I., Pigeon I., West Wallabi I.		Middle I.
Plumbaginaceae
Muellerolimon salicorniaceum		10 islands	Little Rat I., Rat I.	Middle I.
Poaceae
Austrodanthonia caespitosa		East Wallabi I., North I.
Austrostipa crinita		North I.
Austrostipa elegantissima		East Wallabi I., Long I., Oystercatcher I., Pigeon I., Seagull I., Turnstone I., West Wallabi I.		Middle I.
Austrostipa flavescens		Akerstrom I., Oystercatcher I., Seagull I., Tattler I.
Austrostipa variabilis		East Wallabi I., North I., Tattler I., West Wallabi I.	Rat I.
Avena barbata	Bearded Oat	Little Pigeon I., Pigeon I.	Roma I., Wooded I.	Basile I., Pelsaert I.	Naturalised
Avena fatua	Wild Oat	North I.	Alexander I., Little Rat I., Rat I., Serventy I., Suomi I., Wooded I.	Basile I., Burnett Rock, Burton I., Pelsaert I., Uncle Margie I.	Naturalised
Avena sp.		Beacon I., Tattler I.	Bushby I.		Naturalised
Bromus arenarius	Sand Brome	13 islands	13 islands	Burnett Rock, Burton I., Coronation I. Newman I., Pelsaert I., Post Office I., Stick I.
Bromus diandrus	Great Brome	Beacon I., Little Pigeon I., Long I., North I., Pigeon I., Seagull I., Turnstone I.	Alexander I., Campbell I., Gilbert I., Leo I., Wooded I.	Basile I., Burton I., Eight I., Three I.	Naturalised
Bromus hordeaceus	Soft Brome	11 islands		Middle I., Pelsaert I., Square I.	Naturalised
Bromus japonicus var. vestitus		Seal I.			Naturalised
Bromus madritensis	Madrid Brome	North I.			Naturalised
Bromus rubens	Red Brome			Basile I., Burnett Rock, Uncle Margie I.	Naturalised
Bromus sp.			Campbell I.	Gun I., Murray I., One I., Sweet I.	Naturalised
Cynodon dactylon	Couch	East Wallabi I., North I., Pigeon I.	Rat I., Wooded I.		Naturalised
Cynodon sp.			Rat I.
Ehrharta brevifolia	Annual Veldt Grass	East Wallabi I.		Pelsaert I.	Naturalised
Ehrharta longiflora	Annual Veldt Grass	Barge Rock, Beacon I., Little Pigeon I., Pigeon I., Seagull I., Tattler I.	12 islands	Basile Rock, Burton I., Eight I., Gun I., Jackson I., Newman I., Pelsaert I., Uncle Margie I.	Naturalised
Eragrostis dielsii	Mallee Lovegrass	Akerstrom I., East Wallabi I., Little Pigeon I., North I., Pigeon I., Turnstone I.	Little Rat I., Rat I.	Pelsaert I.
Hordeum murinum subsp. leporinum	Barley Grass	Little Pigeon I., North I., Pigeon I.	Alexander Island	Basile I.	Naturalised; in Western Australia this is treated at species rank as Hordeum leporinum.[24]
Lachnagrostis filiformis	Blown Grass	East Wallabi I., West Wallabi I.			Harvey et al. (2001) lists this as Agrostis avenacea, but this is now a synonym of L. filiformis.[25]
Lolium multiflorum	Italian Ryegrass	West Wallabi I.			Naturalised
Lolium perenne	Perennial Ryegrass	West Wallabi I.		Basile I.	Naturalised
Lolium rigidum	Wimmera Ryegrass	Alcatraz I., Little Pigeon I.		Pelsaert I.	Naturalised
Lolium temulentum	Drake		Campbell I., Leo I., Rat I.	Stick I.	Naturalised
Parapholis incurva	Coast Barbgrass	North I.	Bynoe I., Campbell I., Keru I., Leo I., Morley I., Roma I.	Uncle Margie I.	Naturalised
Pennisetum clandestinum	Kikuyu Grass		Little Rat I.		Naturalised
Phalaris canariensis	Canary Grass			Post Office I.	Naturalised
Phalaris minor	Lesser Canary Grass	North I., Pigeon I., East Wallabi I.	Alexander I., Morley I., Serventy I., Suomi I.	Basile I., Burnett Rock, Burton I., Post Office I., Uncle Margie I.	Naturalised
Phleum pratense	Timothy			"Gun Islet"	Naturalised
Poa annua	Winter Grass	Beacon I., East Wallabi I.			Naturalised
Poa poiformis	Coastal Poa	East Wallabi I.
Polypogon monspeliensis	Annual Beardgrass	Little Pigeon I., Long I., West Wallabi I.			Naturalised
Polypogon tenellus		East Wallabi I., Pigeon I., West Wallabi I.
Rostraria cristata		Little Pigeon I., North I., Pigeon I.	Bynoe I., Serventy I.		Naturalised
Setaria dielsii	Diels' Pigeon Grass	16 islands	11 islands	Burnett Rock, Burton I., Gun I., Middle I., Newman I., Pelsaert I., Square I., Three I.
Setaria sp.		Dick I.
Spinifex longifolius	Beach Spinifex	15 islands	13 islands	Burton I., Coronation I., Hummock I., Middle I., Pelsaert I., Post Office I., Stick I., Uncle Margie I.
Sporobolus virginicus	Marine Couch	North I., Oystercatcher I., Pigeon I., Seagull I., Turnstone I., West Wallabi I.		Middle I.
Triticum aestivum	Wheat	North I.			Naturalised
Vulpia myuros	Rat's Tail Fescue	Akerstrom I., East Wallabi I., Little Pigeon I., North I., Pigeon I., Turnstone I., West Wallabi I.	Little Rat I., Rat I., Serventy I.		Naturalised
Polygonaceae
Emex australis	Doublegee	Little Pigeon I., Pigeon I.	Rat I.		Naturalised
Portulacaceae
Calandrinia calyptrata	Pink Purslane	North I.		Rotondella I., Uncle Margie I.
Primulaceae
Anagallis arvensis	Pimpernel	Pigeon I., West Wallabi I.	Alexander I., Bushby I., Little Rat I., Rat I., Serventy I.	Gun I., Middle I., Pelsaert I.	Naturalised
Proteaceae
Grevillea argyrophylla	Silvery-leaved Grevillea	East Wallabi I., North I., Pelican I., Saville-Kent I., West Wallabi I.		Basile I., Middle I., Murray I.
Ranunculaceae
Ranunculus sessiliflorus	Smallflower Buttercup	East Wallabi I.
Rhamnaceae
Spyridium globulosum	Basket Bush	East Wallabi I., North I., West Wallabi I.
Rubiaceae
Galium sp.		East Wallabi I.			Harvey et al. (2001) list this as "Galium migrans" but, according to FloraBase, that species is not present in Western Australia.[26]
Opercularia vaginata	Dog Weed	East Wallabi I.
Rutaceae
Diplolaena grandiflora	Wild Rose	"Eagle Point Islet", East Wallabi I., Little Pigeon I., Oystercatcher I., Pigeon I., Seagull I., Tattler I., Turnstone I., West Wallabi I.	Little Rat I., Rat I.	Gun I.
Santalaceae
Exocarpos aphyllus	Leafless Ballart	East Wallabi I., Little Pigeon I., Long I., Oystercatcher I., Pigeon I., Seagull I., Tattler I., West Wallabi I.
Exocarpos sparteus	Broom Ballart	North I., West Wallabi I.
Sapindaceae
Dodonaea aptera	Coast Hop-bush	East Wallabi I., North I., Oystercatcher I., West Wallabi I.
Dodonaea inaequifolia		East Wallabi I., Oystercatcher I., West Wallabi I.
Dodonaea viscosa	Sticky Hopbush	Seagull I.
Scrophulariaceae
Dischisma arenarium		West Wallabi I.			Naturalised
Solanaceae
Lycium ferocissimum	African Boxthorn		Wooded I.	Arthur I., Davis I., Eight I., Gun I., Pelsaert I., Seven I., Sid Liddon I., Sweet I., Three I.	Naturalised. This has been declared a noxious weed, and an eradication program is in place. Harvey et al. (2001) record the plant on only these ten islands, but in 2007 the Department of Environment and Conservation reported that it had been eradicated from 14 out of 18 islands on which it had previously occurred.[27]
Lycopersicon esculentum	Tomato		Rat I., Roma I.	Jackson I., Middle I.	Naturalised
Nicotiana glauca	Tree Tobacco	Pigeon I.			Naturalised
Nicotiana occidentalis subsp. hesperis	Native Tobacco	14 islands	Alexander I., Morley I., White I., Wooded I.	Middle I., Pelsaert I.
Solanum laciniatum	Kangaroo Apple	East Wallabi I.			Naturalised
Solanum nigrum	Black Berry Nightshade	Beacon I., East Wallabi I., Little Pigeon I., Pigeon I., West Wallabi I.	Bushby I., Little Rat I., Rat I., Roma I.	Eight I., Gun I.	Naturalised
Solanum symonii		Alcatraz I., Beacon I., East Wallabi I., Oystercatcher I., Seagull I.
Sterculiaceae
Lasiopetalum angustifolium	Narrow Leaved Lasiopetalum	East Wallabi I.
Tamaricaceae
Tamarix aphylla	Athel Tree	Pigeon I., West Wallabi I.			Naturalised. Harvey et al. (2001) list this as "Tamarix sp.", but T. aphylla is the only Tamarix species naturalised in Western Australia.[28]
Thymelaeaceae
Pimelea microcephala	Shrubby Riceflower	11 islands
Urticaceae
Parietaria cardiostegia		Dakin I., Saville-Kent I.	Bynoe I., Keru I.	Burton I.
Parietaria debilis	Pellitory	Beacon I., Dakin I., Dick I., Eastern I., East Wallabi I., Long I., North I., Saville-Kent I., West Wallabi I.	Alexander I., Bynoe I., Keru I., Leo I., Little North I., Morley I., Rat I., White I.	13 islands
Urtica urens	Small Nettle	East Wallabi I., West Wallabi I.			Naturalised
Zygophyllaceae
Nitraria billardierei	Nitre Bush	43 islands	30 islands	34 islands	This is the most widespread plant species in the Houtman Abrolhos.
Zygophyllum simile		Beacon I., Dakin I., Dick I., East Wallabi I., Long I., North I., Saville-Kent I., West Wallabi I.