Nymphaea species, especially: / Nuphar species, especially:

Rudbeckia hirta / Rudbeckia pinnata / Echinacea paradoxa

Ranunculus bulbosus (St. Anthony's turnip), of western Europe. / Reseda luteola (dyer's rocket), of Eurasia / Solidago canadensis (Canada goldenrod)

plural of yellow coneflower

Linum flavum, native to Europe / Linum sulcatum, grooved yellow flax, native to eastern North America / Reinwardtia indica, native to the Himalayas

plural of yellow jacket

Any yellow-blooming plant of tribe Genisteae: subfamily Faboideae, especially / Cytisus scoparius / (US) Baptisia tinctoria, of tribe Thermopsideae: subfamily Faboideae.

plural of yellow union

(construction) Equipment for construction and earthmoving tasks. / (retail) Big-ticket items that are rarely purchased and not regularly replaced.

A trade union that is dominated or influenced by an employer and thus not properly independent.