Sagina apetala Annual Pearlwort, Dwarf Pearlwort, New Zealand Moss (*)
Salix babylonica Peking Willow, Weeping Willow (*)
Salvia verbenaca Vervain, Wild Clary, Wild Sage (*)
Sannantha angusta Clarence River Baeckea
Santalum lanceolatum Blue Bush, Bush Plum, Cherry Bush, Desert Quandong, Native Plum, Northern Sandalwood, Plumwood, Tropical Sandalwood, True Sandalwood, Wild Plum
Santalum obtusifolium Blunt Sandalwood, False Sandalwood, Sandalwood
Sarga leiocladum Wild Sorghum
Sauropus hirtellus Thyme Spurge
Scaevola ramosissima Hairy Fan-flower, Purple Fan-flower, Snake Flower
Schkuhria pinnata Dwarf Marigold (*)
Schoenoplectus tabernaemontani Grey Club-rush, River Club-rush
Schoenus apogon var. apogon Common Bog-rush, Fluke Bog-rush
Schoenus maschalinus Leafy Bog-rush
Schoenus melanostachys Black Bog-rush
Scirpus polystachyus Large-headed Club-rush
Scleranthus biflorus Cushion-bush, Cushion Plant, Twin-flowered Knawel, Two-flowered Knawel
Scleria mackaviensis -
Scutellaria humilis Australian Skullcap, Dwarf Skullcap, Skull Cap
Senecio amygdalifolius Almond-leaved Senecio
Senecio bathurstianus Rough Fireweed
Senecio bipinnatisectus Commonwealth Weed
Senecio diaschides Erect Groundsel
Senecio interpositus Tableland Fireweed
Senecio madagascariensis Fireweed, Madagascar Groundsel, Madagascar Ragwort (*)
Senecio minimus Toothed Fireweed
Senecio pinnatifolius var. pinnatifolius Coast Groundsel, Variable Groundsel
Senecio prenanthoides Beaked Fireweed, Common Fireweed
Senecio quadridentatus Auricled Groundsel, Cotton Fireweed
Senecio tenuiflorus Slender Fireweed
Senna barronfieldii Australian Senna, Cassia, Fragrant Senna
Seringia hillii Keraudrenia
Setaria parviflora Small-flowered Pigeon Grass (*)
Setaria pumila subsp. pumila Pale Pigeon Grass, Pigeon Grass (*)
Sigesbeckia australiensis Cobber Weed
Sigesbeckia orientalis Indian Weed
Silene gallica French Catchfly (*)
Smilax australis Austral Sarsaparilla, Barbwire Vine, Lawyer Vine, Wait-a-while
Solanum amblymerum Spiny Kangaroo Apple
Solanum chenopodioides Whitetip Nightshade (*)
Solanum cinereum Narrawa Burr
Solanum ditrichum Mt Maroon Solanum
Solanum physalifolium var. nitidibaccatum Cherry Nightshade (*)
Solanum triflorum Cutleaf Nightshade, Small Nightshade (*)
Solenogyne bellioides -
Soliva anthemifolia Button Burweed, Dwarf Jo-jo (*)
Soliva sessilis Bindyi, Jo-jo, Lawn Burweed (*)
Sonchus asper Prickly Sowthistle, Rough Sowthistle (*)
Sonchus oleraceus Annual Sowthistle, Colewort, Common Milk Sowthistle (*)
Sorghum halepense Aleppo Grass, Evergreen Millet, Johnson Grass (*)
Sorghum x drummondii Sudan Grass (*)
Spergularia rubra Sandspurry, Red Sand-spurrey (*)
Sphaerolobium sp. Globe Pea
Sphaeromorphaea australis Epaltes, Spreading Nut-heads
Spiranthes sinensis Austral Ladies' Tresses, Chinese Spiranthes, Ladies' Tresses, Pink Spiral Orchid
Sporobolus creber Slender Rat's Tail Grass, Western Rat-tail Grass
Sporobolus elongatus Hairy Grass, Rat's Tail Grass, Slender Rat's Tail Grass, Yakka Grass
Sporobolus natalensis Giant Rat's Tail Grass (*)
Spyridium scortechinii Pepper and Salt, Snowballs
Stackhousia monogyna Candles, Creamy Candles, Creamy Stackhousia
Stackhousia muricata Western Stackhousia
Stackhousia viminea Candlesticks, Slender Stackhousia
Stellaria angustifolia subsp. angustifolia Swamp Starwort
Stellaria media Chickweed, Common Chickweed (*)
Stylidium debile Frail Trigger-plant
Stylidium graminifolium Grass Trigger-plant, Grass-leaved Stylidium
Stylidium laricifolium Giant Trigger-plant, Tall Trigger-plant, Tree Trigger-plant
Stylidium paniculatum Frail Trigger-plant
Stypandra glauca Blind Grass, Candyup Poison, Graceful Blue-lily, Grass Lily, Nodding Blue-lily
Styphelia triflora Pink Five-corners, Three-flowered Styphelia
Styphelia viridis subsp. breviflora Green Five-corners, Green-flowered Styphelia
Swainsona galegifolia Indigo Plant, Cranky Pea, Smooth Darling Pea
Swainsona oroboides Kneed Darling Pea, Variable Swainsona
Sylvipoa queenslandica Queensland Grass, Queensland Poa
