Plants That Start With O

Plants that start with the letter O, from the Categorico word game. Here are 15 examples, with many more inside the app. Categorico is a categories word game you can play solo or against friends online.

Word list updated July 26, 2026

15 plants starting with O

1. Oak
2. Oakleaf Hydrangea
3. Oat
4. Oat Grass
5. Ocotillo
6. Okra
7. Old Man's Beard
8. Oleander
9. Oleaster
10. Olive
11. Onion
12. Opuntia
13. Orach
14. Orange
15. Orchid