Leaves & Stem



Stems 
There are many types of stems, ranging from soft and flexible herbaceous, to hard and rigid woody. 




Functions: 
Supportive Role: holds plant up to light.
Nutritional Role: transports water and nutrients through vascular tissue.
















Leaf Layers: 




Epidermis (upper & lower): if unbroken, repels invaders. The cuticle surrounds the leaf, acting as a  waxy covering. This protective layer helps reduce water loss by reducing evaporation. 
Spongy layer (spongy mesophyll): irregularly shapes and loosely packed. Contained in the air spaces of a leaf. These air spaces contain carbon dioxide, oxygen, and nitrogen. 
Vascular Tissue: xylem and phloem forms veins.
Main functions: 
1. Conduct water and dissolved minerals into leaf.
2. Conduct and dissolve carbohydrates out of leaf. 
Palisade Layer (palisade mesophyll): tightly packed cells below epidermis. The structure and shape of the parenchyma cells enable maximum light to penetrate through the transparent layer. This layer contain many chloroplast. Most photosynthesis occurs in this layer. 




  

Plants have been abundant in the Earth for several years. Seed plants first appeared in the fossil record approximately 400 million years ago, while flowering plants appeared in the fossil record approximately 135 million years ago. Over many generations humans developed various uses of plants; food, shelter, medicine, fuel, etc. Plants are significant and vital for our survival.

Issues

Today, we continue to use plants for our various needs. But as we continue to consume, we end up significantly damaging the environment, Through pollution, deforestation, and over consumption, humans are using up more sources on Earth than can be replenished.

Why does this matter?

Ever heard the quote, "If the bee disappears from the surface of the earth, man would have no more than four years to live"? Bees play an important role in pollination. Pollination enables the cycle of fertilization to occur. It is a necessary step for the reproduction of flowering plants. Without pollinators, certain plants won't be able to go through pollination. Fruit, nuts and vegetable crops would be significantly affected by this and food would end up being scarce. Just like humans, animals need plants to sustain life. With food scarce, it will be harder for animals to survive. With less animals and food, it will be harder for humans to survive. And the chain goes on. There is an equilibrium within the ecosystem, it is a cycle that sustains life. Breaking this cycle can cause an ecosystem to be off balance.

Plants are often disregarded in our busy modern world. We begin to interfere with the cycle and destroy the habitats of plants and animals. The damage we've inflicted upon our environment is a current issue and some are trying to accommodate.

What Can I Do?

The little things count. A simple action can go a long way. It is important to be aware about current environmental issues and what you can do to help. Educate yourself and have an understanding of plants and their significance to the environment. This site is for informative purposes, but there are ways to get involve. You can start by clicking the "get involved" section.