Rudbeckia hirta / Rudbeckia pinnata / Echinacea paradoxa

plural of yellow bristle grass

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

plural of yellow coneflower

Pennisetum glaucum (pearl millet) / Setaria parviflora (marsh bristlegrass) / Setaria pumila (yellow foxtail, pigeon grass, cattail grass)

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

A year which is a multiple of one hundred (100) and marks that a century has past and changed to a new century (at the end of the year)

plural of century year

plural of yellow jacket

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