Free Pictures Photos Logo

Leaves 1

Leaves 2
 
Google Facebook LinkedIn Reddit Twitter



In botany, a leaf is an above-ground plant organ specialized for photosynthesis. For this purpose, a leaf is typically flat and thin, to expose the chloroplast containing cells  to light over a broad area, and to allow light to penetrate fully into the tissues. Leaves are also the sites in most plants where respiration, transpiration, and guttation take place. Leaves can store food and water, and are modified in some plants for other purposes. The comparable structures of ferns are correctly referred to as fronds.
As a stem grows, leaves tend to appear arranged around the stem in away that optimizes yield of light. In essence, leaves come off the stem in a spiral pattern, either clockwise or counterclockwise, with the same angle of divergence. 
Two basic forms of leaves can be described considering the way the blade is divided. A simple leaf has an undivided blade. However, the leaf shape may be one of lobes, but the gaps between lobes do not reach to the main vein. A compound leaf has a fully subdivided blade, each leaflet of the blade separated along a main or secondary vein. Because each leaflet can appear to be a "simple leaf", it is important to recognize where the petiole occurs to identify a compound leaf.

A leaf (plural leaves) is a flattened structure of a higher plant, typically green and blade like that is attached to a stem directly via a stalk (oxford dictionary). They exist in various types, shapes, and sizes.


Their structure
The outermost layer of a leaf is called the epidermis. This layer is protected by cellulite. These plant structures have both upper and lower epidermis. This layer is important for gaseous exchange process. The epidermis also has tiny opening known as stomata which are used in photosynthesis. 
They are covered by a waxy substance known as the cuticle. This layer helps to prevent excessive water loss from the surface.


Some also have small hairs on their surface. These are referred d to as trichomes. Their function is to reduce consumption by plants and insects by storing toxic and bad tasting compounds in them. Their general structure consists of a midrib, blade, and a margin. Its edge is what is referred to as the margin. Some are attached to their stem directly while others are attached using a petiole. 
They have veins running across and among them. Venation pattern is the arrangement of veins in the lamina. They exist in two types of venation; reticulate and parallel. Reticulate venation is characterized by their organization in a net-like pattern. This is found in di-cotyledons; rese, maple, hibiscus, and tulsi. 
Parallel venation involves veins running parallel to each other. This is found in monocotyledons; bananas, palm, onions, and grass.

Their arrangement on a plant
Phyllotaxy is the arrangement of leaves on a stem. Each botanical species has its own unique arrangement. It can be; alternate, spiral, opposite or whorled. Alternate and spiral are characterized by having only one of them per node. 
In the alternative, they are organized on each side of the stem in a flat plane. Two or more connected to a node makes a whorled pattern. 
Most arrangements enable them to optimize the yield of light.

Types 
The major classification is simple and compound. Simple ones contain blades that are undivided. They are not divided into smaller units. They have a toothed edge which can either be unlobed or lobed. Lobed ones contain gaps in between them but will not reach the midrib of leaves. 
Compound ones consist of leaflets which are attached to a rachis

Photosynthesis
This is the process by which green plants make their own food. They do this by transforming light energy into chemical energy. Light energy penetrates through the leaves and is used to convert water, minerals and carbon dioxide into oxygen. Therefore, oxygen is the by-product of this process. It is excreted through the stomata. A lot of water is usually lost during this process simply from the leaves.

Photosynthesis plays a key role in maintaining the creatures on earth. Without it, there probably wouldn’t be enough food or other organic matter. It helps in maintaining oxygen levels in the atmosphere. Most earthly organisms completely depend on oxygen for their survival. It is utilized in the human bodies to maintain healthy organs and also keep the heart beating.

The energy produced during photosynthesis is used in creating fossil fuels (coal, oil, gas). Fossil fuels are formed from remains of plants (leaves) organisms that eat them which were trapped under the earth’s crust. Because they were sheltered from any oxidation, fossil fuels slowly began to form. Once the fossil fuels were discovered, they have been utilized in several industries homes and forms of transportation. They are also highly utilized in the manufacture of synthetic materials and plastics.

Chlorophyll
Chlorophyll is the pigment that is responsible for their green color. It is beneficial to both botanic and other organisms. Consumption of extracted chlorophyll by a human being can cause; skin healing, stimulation of the immune system, detoxification, intestinal cleansing, increased energy levels and prevention of cancer.

Conclusion
Leaves may look like tiny organisms but they clearly pack a punch, meanwhile these leaves are functional and beneficial to most living organisms. On top of that, they look amazing and contribute to the aesthetics of our planet. Grassy forested parks mostly have visitors because of the magnificent color and appeal of these structures. Some are also a great source of vitamins when consumed.



leaves-01.jpg (1843055 Byte) leaf leaves picture
leaves-02.jpg (1289982 Byte) leaf picture
leaves-03.jpg (1400633 Byte) leaf picture
leaves-04.jpg (1363349 Byte) leaf picture
leaves-05.jpg (1468270 Byte) picture leaf
leaves-06.jpg (1064383 Byte) picture leaves
leaves-07.jpg (1412573 Byte) picture leaves
leaves-08.jpg (1438043 Byte) picture leaves
leaf-09.jpg (1385582 Byte) picture leaves
leaf-10.jpg (1245688 Byte) picture leaves
leaf-11.jpg (1131706 Byte) picture leaves
leaves-12.jpg (1440446 Byte) picture leaves
leaf-13.jpg (1181457 Byte) image leaves
leaves-0q2g.jpg (1427167 Byte) image leaves
leaves-n7ua.jpg (1314528 Byte) photo leaves
leaves-opl4.jpg (1477885 Byte) pic leaves
leaves-1jyp.jpg (1683721 Byte) water leaves
leaves-3ley.jpg (1328021 Byte) leaf picture
leaves-7zu6.jpg (1812421 Byte) leaf picture
leaves-ai8d.jpg (1753920 Byte) leaf picture
leaves-ay2l.jpg (1385413 Byte) leaf picture
leaves-btgb.jpg (1472086 Byte) leaf picture
leaves-g2xl.jpg (1451678 Byte) leaf picture
leaves-gc7m.jpg (1338360 Byte) leaf picture
leaves-h6g8.jpg (1403707 Byte) leaf picture
leaves-j60o.jpg (1402660 Byte) leaf picture
leaves-a02h.jpg (1316959 Byte) photos design
leaves-h5a0.jpg (1554972 Byte) free images
leaves-kijj7.jpg (1570729 Byte) free nature pictures
leaves-hbg5.jpg (1591145 Byte) nature gallery
leaves-kij67.jpg (1545335 Byte) nature photos
leaves-5djg.jpg (1345111 Byte)
leaves-7v3p.jpg (1748596 Byte)
leaves-m3kh.jpg (1540817 Byte)
leaves-y0y1.jpg (1761676 Byte)
leafs-n7z.jpg (1335432 Byte) images leaf
leaves-g6w1.jpg (1463274 Byte)
leaves-j9o2.jpg (1077272 Byte)
leaves-j74r.jpg (1771929 Byte)
leaves-k84n.jpg (1030604 Byte) red leaves
leaf-0vt2.jpg (1703360 Byte)
leaf-5jd3.jpg (1637676 Byte)
leaves-c7q.jpg (1577458 Byte) leaf images
leaves-n73j.jpg (1207809 Byte)
leaf-ck3j.jpg (1372620 Byte)
leaf-ibi1.jpg (1278145 Byte)
leaf-my7b.jpg (1252128 Byte)
leaf-n7u1.jpg (1474455 Byte)
leaves-k9i1.jpg (1603983 Byte)
leaves-kmj3.jpg (1545085 Byte)
leaves-l1k2.jpg (1732595 Byte)
leaves-ly9q.jpg (1574924 Byte)
leaves-mval.jpg (1780079 Byte)
leaf-8ey2.jpg (1658891 Byte)
leaves-hfr5.jpg (1637250 Byte)
leaves-juh6t.jpg (1637145 Byte)
leaves-h7nu.jpg (1329587 Byte)
leaves-x69a.jpg (1532679 Byte)
leaves pictures
pictures of leaves
nature
tree
green
branch
wall
green
red green
plant
green
blue sky
forest
nature
exotic
bush
tree
nature
fern
brown
lake
withered
plant
nature
lake
branch
plant
nature
green
bush
nature
stones
green
rotten
plant
green
plant
nature