Leaves of three let it be

1. - A condition where the skin becomes red, swollen, or sore.
4. - A naturally occurring compound containing nitrogen.
6. - Trees or plants that shed their leaves annually.
7. - The process by which green plants use sunlight to synthesize foods.
9. - The scientific study of plants.
11. - Interaction between two different organisms living in close physical association.
13. - The arrangement of veins in a leaf.
14. - Sensitivity of an organism to light.
16. - The stalk that joins a leaf to a stem.
18. Ivy - A plant known for its trifoliate leaves and irritant oil.
19. Leaf - A type of leaf divided into several leaflets.
20. - The leaves of a plant.

2. - The process of change by which an organism becomes better suited to its environment.
3. - The layer of vegetation beneath the forest canopy.
5. - A reproductive cell that can develop into a new individual.
8. - The green pigment in plants that helps in photosynthesis.
10. - Having three leaves or leaflets.
12. - The natural home or environment of an organism.
15. - The genus that includes poison ivy, oak, and sumac.
17. - The study of interactions between organisms and their environment.