Hardheads: Russian Knapweed, Turkestan Thistle: Acroptilon repens (Synonym: Centaurea repens) - ?
Pathfinder, Trailplant: Adenocaulon bicolor -
Western Boneset, Western Snakeroot: Ageratina occidentalis (Synonym: Eupatorium occidentale) -
Beach Burs and Ragweeds: The Genus Ambrosia -
Pearly Everlasting, Western Pearly Everlasting: Anaphalis margaritacea -
False Neststraw, Woolly Fishhooks: Ancistrocarphus filagineus (Synonym: Stylocline filaginea) -
Pussytoes: The Genus Antennaria -
Burdock: The Genus Arctium -
Arnicas and Lepordbanes: The Genus Arnica - Several species of Arnicas have disoid flower heads.
Mugworts, Sageworts and Wormwoods: The Genus Artemisia -
Baccharis and Coyote Brush: The Genus Baccharis -
Beggarticks: The Genus Bidens -
Tasselflowers: The Genus Brickellia -
Silvercrown: The Genus Cacaliopsis -
Thistles: The Genus Carduus -
Distaff Thistles and Safflowers: The Genus Carthamus -
Cornflowers, Knapweeds and Starthistles: The Genus Centaurea -
Dustymaidens and False Yarrow: The Genus Chaenactis -
Thistles: The Genus Cirsium -
Blessed Thistle: Cnicus benedictus (Synonym: Centaurea benedicta) -
Brass Buttons and Cotula: The Genus Cotula -
Tall Marsh Elder, Burweed Marsh Elder, Carelessweed: Cyclachaena xanthifolia (Synonym: Iva xanthifolia) -
German Ivy, Cape Ivy: Delairea odorata (Synonym: Senecio mikanioides) -
Burnweeds and Fireweeds: The Genus Erechtites -
Goldenweeds and Rabbitbrush: The Genus Ericameria -
Waldo Daisy: Erigeron bloomeri var. nudatus -
Cudweeds: The Genus Euchiton (Synonym: Gnaphalium) -
Cottonroses and Cudweeds: The Genus Filago (Synonym: The Genus Logfia) -
Cudweeds:The Genus Gnaphalium (Synonym: The Genus Pseudognaphalium) -
Whitney's Goldenweed: Hazardia whitneyi var. discoidea (Synonym: Haplopappus whitneyi ssp. discoideus) -
Hesperevax: The Genus Hesperevax -
Silverback Luina, Littleleaf Luina, Little-leaf Silverback: Luina hypoleuca -
Pineapple Weed, Disc Mayweed: Matricaria discoidea (Synonyms: Chamomilla suaveolens, Matricaria matricarioides) -
Slender Cottonweed: Micropus californicus var. californicus -
Scotch Cottonthistle, Scots Thistle, Scotch Thistle, Cotton Thistle: Onopordum acanthium -
Butterburs and Coltsfoots: The Genus Petasites -
Woollyheads: The Genus Psilocarphus -
Narrowhead Goldenweed: Pyrrocoma carthamoides var. cusickii (Synonym: Haplopappus carthamoides var. cusickii) - ? Ray flowers very reduced or obscure. The flower head may appear discoid.
Silvery Raillardella, Silky Raillardella: Raillardella argentea -
Rainiera, False Silverback, Tongue-leaved Luina: Rainiera stricta (Synonym: Luina stricta) -
Western Coneflower, Western Chocolate Cone: Rudbeckia occidentalis (Synonyms: Rudbeckia occidentalis var. montana, Rudbeckia occidentalis var. occidentalis) -
American Sawwort, American Saw-wort: Saussurea americana -
Butterweeds, Groundsel and Ragworts: The Genus Senecio -
Milk Thistle, Blessed Milk-thistle: Silybum marianum -
Prickly Soliva, Common Soliva, Field Burrweed, Perennial Sow-thistle, Corn Sow-thistle: Soliva sessilis (Synonym: Soliva pterosperma) -
Wirelettuce: The Genus Stephanomeria -
Feverfew and Tansy: The Genus Tanacetum -
Cockleburs: The Genus Xanthium -