Tree sap is widely recognized for its sticky nature, a property often encountered by anyone who has parked under a tree or brushed against a branch. This stickiness is a characteristic feature of the fluid that circulates within trees, and understanding its composition reveals why it behaves this way. The stickiness serves various functions for the tree itself.
Understanding Tree Sap
Tree sap is a watery substance flowing through a tree’s vascular system, similar to blood in animals. It transports water, minerals, and hormones from roots to leaves, and sugars from leaves to other parts of the tree. This vital fluid is essential for a tree’s growth, hydration, and survival.
Sap and resin are often confused but are distinct substances. Both are tree exudates, but sap is water-based, containing dissolved nutrients, sugars, and hormones. Resin, found in coniferous trees like pines, firs, and spruces, is thicker, tackier, and often darker. Resin serves as a protective barrier, sealing wounds and deterring pests, while sap transports nutrients.
The Science Behind Sap’s Stickiness
Tree sap’s stickiness comes from its chemical composition, especially sugars, carbohydrates, and complex polymers. Phloem sap, one of the two main types, is rich in sugars like sucrose, glucose, and fructose, produced during photosynthesis. These sugars provide energy for the tree’s growth and development, and contribute to the sap’s viscous, adhesive texture when it exudes and water evaporates.
This stickiness serves multiple adaptive purposes for the tree. When a tree is damaged, sap oozes out, forming a sticky layer that acts as a natural bandage. This protective barrier seals wounds, preventing further damage and protecting the tree from bacterial and fungal infections. It also deters pests by physically trapping insects.
Dealing with Sticky Sap
Encountering sticky sap on skin, clothing, or vehicles can be a nuisance. Sap is challenging to remove due to its adhesive properties and tendency to harden when exposed to air. Prompt action is recommended to prevent the sap from setting, which makes removal more difficult.
For removal from skin, cooking oils like olive oil, vegetable oil, or even peanut butter can be effective. These oily substances break down the sap’s sticky compounds, allowing it to be rubbed off before washing with soap and water. For clothing, methods include freezing the item to make the sap brittle, then scraping it off, or applying rubbing alcohol or hand sanitizer, which dissolve the sap before washing.
Removing sap from car paint requires a gentle approach to avoid damaging the finish. Mild car wash soap and warm water work for fresh sap. For stubborn spots, isopropyl alcohol (rubbing alcohol) or dedicated bug and tar removers are often used with a microfiber cloth. Rinse the area thoroughly after using any solvent and consider reapplying wax to protect the paint.