In my garden, I'm growing broccoli. I was spraying it with water the other day, and I noticed that water bounced off the leaves. When I just misted it instead of a full-on spray, the water beads collected, but stayed as beads instead of spreading out. Some of them bounced off, but some accumulated. So what makes that happen? I know the leaf is hydrophobic, but I haven't found by searching Google if there's a coating of some type on the leaf or if it's something else that's making it hydrophobic.
This is due to presence of a hydrophobic chemical called as cutin present at the the aerial surfaces of plants.
Cutin is one of two waxy polymers that are the main components of the plant cuticle, which covers all aerial surfaces of plants. The other major cuticle polymer is cutan, which is much more readily preserved in the fossil record,. Cutin consists of omega hydroxy acids and their derivatives, which are interlinked via ester bonds, forming a polyester polymer of indeterminate size.