they are called water leaves not solar leaves
What something is called and what functions something performs can be two totally different things.
Here is a small amount of information about plant leafs and their functions. Kindly pay attention to the portions that are
BOLD, RED and UNDERLINED.
LEAVES
The blade of a leaf is the expanded, thin structure on either side of the midrib. The blade is usually the largest and most conspicuous part of a leaf. The petiole is the stalk which supports the leaf blade. It varies in length and may be lacking entirely in some cases where the leaf blade is described as sessile or stalkless.
The principal function of leaves is to absorb sunlight for the manufacturing of plant sugars in a process called photosynthesis. Leaves develop as a flattened surface in order to present a large area for efficient absorption of light energy. The leaf is supported away from the stem by a stem-like appendage called a petiole. The base of the petiole is attached to the stem at the node. The small angle formed between the petiole and the stem is called the leaf axil. An active or dormant bud or cluster of buds is usually located in the axil.
The leaf blade is composed of several layers. On the top and bottom is a layer of thickened, tough cells called the epidermis. The primary function of the epidermis is protection of leaf tissue. The way in which the cells in the epidermis are arranged determines the texture of the leaf surface. Some leaves have hairs that are an extension of certain cells of the epidermis. The African violet has so many hairs that the leaf feels like velvet.
Part of the epidermis is the cuticle, which is composed of a waxy substance called cutin that protects the leaf from dehydration and prevents penetration of some diseases. The amount of cutin is a direct response to sunlight, increasing with increasing light intensity. For this reason, plants grown in the shade should be moved into full sunlight gradually, over a period of a few weeks, to allow the cutin layer to increase and to protect the leaves from the shock of rapid water loss or sun scald. The waxy cutin also repels water and can shed pesticides if spreader-sticker agents or soaps are not used. This is the reason many pesticide manufacturers include some sort of spray additive to adhere to or penetrate the cuticle.
Some epidermal cells are capable of opening and closing. These cells guard the interior of the leaf and regulate the passage of water, oxygen, and carbon dioxide through the leaf. These regulatory cells are called guard cells. They protect openings in the leaf surface called stoma. The opening and closing of the cells are determined by the weather. Conditions that would cause large water losses from plants (high temperature, low humidity) stimulate guard cells to close. Mild weather conditions leave guard cells in an open condition. Guard cells will close in the absence of light. A large percentage of stomata occur in the lower epidermis.
The middle layer of the leaf is the mesophyll and is located between the upper and lower epidermis. This is the layer in which photosynthesis occurs. The mesophyll is divided into a dense upper layer, called the palisade layer, and a spongy lower layer that contains a great deal of air space, called the spongy mesophyll. The cells in these two layers contain chloroplasts which are the actual sites of the photosynthetic process.
Types of Leaves
A number of rather distinct types of leaves occur on plants. Leaves commonly referred to as foliage are the most common and conspicuous, and as previously stated, serve as the manufacturing centers where the photosynthetic activity of the plant occurs.
Scale leaves or cataphylls are found on rhizomes and are also the small, leathery, protective leaves which enclose and protect buds.
Seed leaves, or cotyledons, are modified leaves which are found on the embryonic plant and commonly serve as storage organs.
Spines and tendrils, as found on barberry and pea, are specialized modified leaves which protect the plant or assist in supporting the stems.
Storage leaves, as are found in bulbous plants and succulents, serve as food storage organs. Other specialized leaves include
bracts, which are often brightly colored. The showy structures on dogwoods and poinsettias are bracts, not petals.
Conifers, (pines, firs, spruce, laurel, etc.) have "needles" as leaves. They normally have waxy cuticles with sunken stomata to help deter desiccation. Also, most have resin canals on either side of the vascular system. The resin is thought to help deter and guard against insect damage.
[FONT=Times New Roman, Times, serif]Major Plant Organs and Their Functions[/FONT]
[FONT=Times New Roman, Times, serif]1. The Leaf[/FONT]
[FONT=Times New Roman, Times, serif]The leaf of a plant serves two basic functions: i) photosynthesis, and ii) cellular respiration.[/FONT]
[FONT=Times New Roman, Times, serif]i) Photosynthesis[/FONT]
[FONT=Times New Roman, Times, serif]Photosynthesis is a chemical reaction in which plants convert radiant energy (light energy) into chemical energy (food energy or more specifically, glucose).[/FONT]
[FONT=arial, helvetica, sanserif]Leaves[/FONT]
[FONT=arial, helvetica, sanserif]Function and structure[/FONT]
The principal function of leaves is to absorb sunlight to manufacture plant sugars through a process called photosynthesis. Leaf surfaces are flattened to present a large area for efficient light absorption. The blade is the expanded thin structure on either side of the midrib and usually is the largest, most conspicuous part of a leaf (Figure 11).
A leaf is held away from its stem by a stem-like appendage called a
petiole, and the base of the petiole is attached to the stem at a
node. Petioles vary in length or may be lacking entirely, in which case the leaf blade is described as
sessile or stalkless.
The node where a petiole meets a stem is called a leaf
axil. The axil contains single buds or bud clusters, referred to as axillary buds. They may be either active or dormant; under the right conditions, they will develop into stems or leaves.
A leaf blade is composed of several layers (Figure 12a and Figure 12b: click on images to display larger versions.). On the top and bottom is a layer of thick, tough cells called the
epidermis. Its primary function is to protect the other layers of leaf tissue. The arrangement of epidermal cells determines the leaf's surface texture. Some leaves, such as those of African violet, have hairs (
pubescence), which are extensions of epidermal cells that make the leaves feel like velvet.
The
cuticle is part of the epidermis. It produces a waxy layer called
cutin, which protects the leaf from dehydration and disease. The amount of cutin on a leaf increases with increasing light intensity. For this reason, when moving plants from shade into full sunlight, do so gradually over a period of a few weeks. This gradual exposure to sunlight allows the cutin layer to build up and protect the leaves from rapid water loss or sunscald.
The waxy cutin also repels water. For this reason, many pesticides contain a spray additive to help the product adhere to, or penetrate, the cutin layer.
Special epidermal cells called
guard cells open and close in response to environmental stimuli, such as changes in weather and light. They regulate the passage of water, oxygen, and carbon dioxide into and out of the leaf through tiny openings called
stomata. In most species, the majority of the stomata are located on the underside of leaves.
Conditions that would cause plants to lose a lot of water (high temperature, low humidity) stimulate guard cells to close. In mild weather, they remain open. Guard cells also close in the absence of light.
Located between the upper and lower epidermis is the
mesophyll. It is divided into a dense upper layer (palisade mesophyll) and a lower layer that contains lots of air space (spongy mesophyll). Located within the mesophyll cells are
chloroplasts, where photosynthesis takes place.
The principal function of leaves is to absorb sunlight for the manufacturing of plant sugars in a process called photosynthesis &[FONT=Times New Roman, Times, serif] [/FONT][FONT=Times New Roman, Times, serif]The leaf of a plant serves two basic functions: i) photosynthesis, and ii) cellular respiration. [/FONT][FONT=Times New Roman, Times, serif]Photosynthesis is a chemical reaction in which plants convert radiant energy (light energy) into chemical energy (food energy or more specifically, glucose).
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Kinda makes ya' wonder why they might be called water leaves rather than solar leaves when you consider the primary function of plant leaves, doesn't it?[/FONT][FONT=Times New Roman, Times, serif]
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