| Zanthoxylum americanum P. Mill. | map | |
| Zanthoxylum clava-herculis L. | map | images (1) (2) |
| Zea mays L. | map | |
| Zenobia pulverulenta (Bartr. ex Willd.) Pollard | map | |
| Zephyranthes atamasca (L.) Herbert | map | images (1) (2) |
| Zephyranthes candida (Lindl.) Herbert | map | images (1) (2) |
| Zephyranthes simpsonii Chapman | map | |
| Zigadenus densus (Desr.) Fern. | map | |
| Zigadenus glaberrimus Michx. | map | images (1) (2) (3) (4) |
| Zizania aquatica L. | map | images (1) (2) (3) (4) (5) |
| Zizaniopsis miliacea (Michx.) Doell & Aschers | map | |
| Zizia aptera (Gray) Fern. | map | |
| Zizia aurea (L.) W.D.J. Koch | map | |
| Zizia trifoliata (Michx.) Fern. | map | |
| Zornia bracteata J.F. Gmel. | map | |