| Q |
| Quaking oats, Briza maxima |
| Quamash, Camassia |
| Queen Anne's lace, False, Ammi majus |
| Queen Anne's lace; Wild carrot, Daucus carota |
| Queen Elizabeth rose, Rosa 'Queen Elizabeth' |
| Queen of Beauty Fragrance rose, Rosa 'Souvenir de la Malmaison' |
| Queen of England rose, Rosa 'Queen of England' |
| Queen of the Lakes rose, Rosa 'Queen of the Lakes' |
| Queen of the meadow; Joe-pye-weed, Eupatorium maculatum |
| Queen of Whites water lily, Nymphaea 'Queen of Whites' |
| Quince, Chinese, Cydonia sinensis = Pseudocydonia sisensis |
| Quince, Flowering, Chaenomelea speciosa |
| Quince, Japanese flowering, Chaenomelea japonica |
| Quinine, Wild, Parthenium integrifolium |