Lycophyta

//__Lycophyta __//
 * Kingdom: **Plantae** ||
 * Division: **Lycopodiophyta** ||



Most plants included in the Lycophyta phylum are underbrush plants that survive in tropical or subtropical climates. Certain species of plants are also hydrophytes, which are aquatic plants, and epiphytes, which are non-parasitic plants that grow off of other plants. There are also a few desert plants that live in desert environments. Lycophyta phylum plants presently grow to be about the size of a miniature pine tree or tall mosses, but do not go over 30 cm tall.[1]

Plants in the Lycophyta phylum are vascular plants that have vascular tissue that is arranged in the stem. In some plants there are strips of xylem that alternate with other tissue at the core of the stem. In other plants though, core made of other tissue is walled by xylem. Also, phloem, cortical tissue and an epidermis is also scene in Lycophyta plants. Other things that are unique about this phylum are the leaves which have a single nerve that transports water and nutrients. The leaves are known as microphylls which developed independently. __[1]__

The Lycophyta phylum plants contain spores which is a single-celled reproductive body that can be resistant to heat. Spores are also able to grow into a new organism. In this case, the spores are located in the kidney-shaped sporangia on the sporophylls, which are leaves that have sporangia. In Lycophyta phylum plants, metagenesis occurs which is when the diploid sporophyte generation takes over. In certain species, the haploid gametophyte develops in the wall of the sporangium. A haploid gametophyte does not contain a chlorophyll, and is small and fleshy. [1]

**//Plants in the Lycophyta phylum consist of Club mosses, Spike mosses, and Quillworts.__ [3] __ //** Club mosses are small, terrestrial, vascular plants that do not have flowers. The reproduce sexually by spores and the sporophyte is of true roots, aerial stem and scale-like leaves. Club moss leaves are microphylls and they are small and spirally. The leaves are attached to an elongated stem.[4]

Spike mosses grow in tropical climates and are rarely found in the desert. They are terrestrial, perennial plants that do not have true roots. They have branched stems and their leaves are simple and are in four rows. Two of the rows have long leaves and two of the rows have short leaves.[5]

Quillworts are small and spore-bearing plants with narrow elongated leaves. Their leaves are microphyllous and are vascular plants. Quillworts have leaves that contain air chambers that collect carbon dioxide. Their leaves are spiral shaped and they have a short stem. Each leaf of the Quillwort has a base where the sporangia are located. The roots of this plant do not have vascular tissue.[6]

**__Classification __** <span style="font-family: 'Cambria','serif'; font-size: 16px;">In the Lycophyta phylum there are about 1,200 different types of plants. These are split up into three known as Lycopodiales, Isoetales, and Selaginellales. Bellow is the <span style="color: black; font-family: 'Cambria','serif'; font-size: 16px;">list of classes of the Lycophyta, in a classical morphology-based classification system.<span style="color: #0000ff; font-family: 'Cambria','serif'; font-size: 110%; line-height: 115%;">[7]


 * <span style="font-family: 'Cambria','serif'; font-size: 16px; line-height: 150%;">Class Lycopodiopsida – Firmosses & Club mosses
 * <span style="font-family: 'Cambria','serif'; font-size: 16px; line-height: 150%;">Class Isoetopsida – Scale trees, Spike mosses, & Quillworts
 * <span style="font-family: 'Cambria','serif'; font-size: 16px; line-height: 150%;">Class Zosterophyllopsida – Extinct Zosterophylls

**__<span style="font-family: 'Cambria','serif'; font-size: 16px;">Vascular System __** <span style="font-family: 'Cambria','serif'; font-size: 16px;">A plants vascular system is a collection of tissues and fibers. Two types of tissues are Xylem tissue and Phloem tissue. Xylem tissue takes water and dissolved minerals to the leaves, while the phloem tissue controls the food that travels from the leaves to other part of the plant. The xylem core is located in the protostele, which is where the stele forms the solid core xylem covered by phloem. The siphonostele is a type of stele where the vascular cylinder surrounds a pith. An example of this would be the <span style="color: black; font-family: 'Cambria','serif'; font-size: 16px;"> stem of a sunflower. The vascular system of monocots, types of grasses, is discontinuous. A plants vascular system is made up of <span style="font-family: 'Cambria','serif'; font-size: 16px;">scattered vascular bundles. These bundles are a transport system that is arranged with the stems of dicots. An example of a dicot would be a rose.<span style="font-family: 'Cambria','serif'; font-size: 16px; line-height: 115%;">[8]

<span style="font-family: 'Cambria','serif'; font-size: 16px;">Vascular rays are a band of parenchymatous cells that are part in the xylem and part in the phloem of a plant root or stem. The root or stem is what carries out fluids radially and shows up in a cross section. What complete the stele is the vascular and supporting tissues. <span style="color: #0000ff; font-family: 'Cambria','serif'; font-size: 16px; line-height: 115%;">[8]

**__<span style="font-family: 'Cambria','serif'; font-size: 16px;">Roots, Stems, Leaves __**

**//<span style="font-family: 'Cambria','serif'; font-size: 16px;">Roots //**

<span style="font-family: 'Cambria','serif'; font-size: 16px; line-height: normal; margin: 0in 0in 0pt;">The roots main function is to absorb water and nutrients from the soil to give to the plant. Roots also act as an anchor for the plant by holding it upright and keeping it in the ground. Roots help to prevent erosion by holding the soil in place, and they protect the soil surrounding the plant from soil bacteria. The roots of a plant support the plant and provide a means of transportation for water and nutrient. Roots also have root hairs that absorb moisture and mineral.<span style="color: #0000ff; font-family: 'Cambria','serif'; font-size: 16px; line-height: 115%;">[9]

<span style="font-family: 'Cambria','serif'; font-size: 16px;">The structure of the roots is similar to the structure of the stem. If a root is old, it will have xylem, phloem and cambium. Phloem is bark that carries manufactured food down, while xylem is wood that carried water and minerals up. What separate the phloem and xylem is the cambium, which is what produces new cells. <span style="color: #0000ff; font-family: 'Cambria','serif'; font-size: 16px; line-height: 115%;">[9] **//<span style="font-family: 'Cambria','serif'; font-size: 16px;">Stems //**

<span style="font-family: 'Cambria','serif'; font-size: 16px;">Plant stems can grow to be many different sizes and forms, and they help to support the plant body. The stems main function is the movement of water and minerals from the roots upward. The stems second main function is the movement of manufactured food down. It provides a place where the plant can store its food and stems manufacture food like leaves do. The stem helps to keep the rest of the plant safe from infections and predators. A stem can grow to be a few millimeters to 100 meters tall. Stems have breathing pores known as lenticels and bud scale scars that help determine the plants past. Inside of a stems there is phloem and xylem. <span style="color: #0000ff; font-family: 'Cambria','serif'; font-size: 16px; line-height: 115%;">[9]

**//<span style="font-family: 'Cambria','serif'; font-size: 16px;">Leaves //**

<span style="font-family: 'Cambria','serif'; font-size: 16px;">Plant leaves include two main functions which are Photosynthesis and Cellular Respiration. Photosynthesis is the process where a cell captures energy in sunlight and uses it to make food energy. The reactants for the process of photosynthesis are water, carbon dioxide, chlorophyll, and sunlight. The products for the process are glucose (food energy), oxygen, and water. Both the reactants and products is what are needed in order for the process of photosynthesis to take place. Cellular Respiration is the process by which your food is broken down into the glucose molecule and the energy they contain is released. <span style="color: #0000ff; font-family: 'Cambria','serif'; font-size: 16px; line-height: 115%;">[9]

<span style="font-family: 'Cambria','serif'; font-size: 16px;">Plant leaves are known as the food factory of a plant and they produce the food on their own and store it to use later on. Leaves are known to different shapes depending on the plant they are connected to. The leaves are what people use to identify what type of plant it is. The stalk of a leaf is called petiole, and the actual leaf is called a leaf blade. The leaf blade has veins which help to form the structure of a leaf. The large center vein is called the midrib, which is what all the other leaf veins are connected to. The edge of a leaf is called margins and they help people to identify the type of plant. <span style="color: #0000ff; font-family: 'Cambria','serif'; font-size: 16px; line-height: 115%;">[9]

<span style="font-family: 'Cambria','serif'; font-size: 16px;">The thin outermost layer of the skin is called the epidermis, which protects the leaf from loss of too much moisture. The small pores on the underside of leaves are called guard cells. The small pores open and close, allowing certain substances to pass in and out. The lower side of the epidermis has stomata which allow the plant to breathe and gives off moisture. <span style="color: #0000ff; font-family: 'Cambria','serif'; font-size: 16px; line-height: 115%;">[9]

**__<span style="font-family: 'Cambria','serif'; font-size: 16px;">Evolutionarily successful __** <span style="font-family: 'Cambria','serif'; font-size: 16px; line-height: normal; margin-bottom: 0pt;">The Lycophyta phylum is a group of very advanced and successful plants. Plants in this phylum, such as club mosses, survive best in the wetlands and have been around for generations. The Lycophyta phylum contains ancient species, some now extinct, that were very successful throughout the dinosaur era. This group of spore-bearing, vascular plants has a long evolutionary history that dates back to the Paleozoic Era.<span style="font-family: 'Cambria','serif'; font-size: 16px; line-height: 115%;">[10]

**__<span style="font-family: 'Cambria','serif'; font-size: 16px;">External Links __**

<span style="font-family: 'Cambria','serif'; font-size: 16px; line-height: normal; margin-bottom: 0pt;">[|Plant Kingdom] <span style="font-family: 'Cambria','serif'; font-size: 16px; line-height: normal; margin-bottom: 0pt;">[|Plant Structure] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|Lycophyta (Club Moss)] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|Lycophyta (Scale trees and Club Mosses)] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|Plant Vascular Systems] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|Plant Vascular System Development] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|Vascular System] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|Plant Structure and Function] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|Chapter 46 – Plant Structure] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|The Great Plant Escape] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|A General Plant Structure] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|Plant Structure and Development] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|Lycopodiophyta] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|Phylum Lycophyta] <span style="font-family: 'Cambria','serif'; font-size: 16px; font-weight: normal; margin: 0in 0in 0pt;">[|Kingdom Plantae]

__**Footnotes**__

<span style="font-family: 'Calibri','sans-serif'; font-size: 13px; line-height: 115%;">[1] “Living Lycophytes.” //Myfundi – Your Online Encyclopedia//. MyFundi.co.za. Web. 25 May. 2011. <span style="font-family: 'Calibri','sans-serif'; font-size: 13px; line-height: 115%;">[2] “Spore.” //The Free Dictionary//. Farlex, Inc., 2011. Web. 25 May. 2011. <span style="font-family: 'Calibri','sans-serif'; font-size: 13px; line-height: 115%;">[3] Gregory, Michael. “Phylum Lycophyta.” //The Biology Web//. 18 Apr. 2006. Web. 26 May. 2011. <span style="font-family: 'Calibri','sans-serif'; font-size: 13px; line-height: 115%;">[4] “Family: Lycopodiaceae – Club Mosses.” //The Hidden Forest//. Web. 26 May. 2011. <span style="font-family: 'Calibri','sans-serif'; font-size: 13px; line-height: 115%;">[5] “Family: Selaginellaceae.” //The Hidden Forest//. Web. 26 May. 2011. <span style="font-family: 'Calibri','sans-serif'; font-size: 13px; line-height: 115%;">[6] “Family: Isoetaceae.” //The Hidden Forest//. Web. 26 May. 2011. <span style="font-family: 'Calibri','sans-serif'; font-size: 13px; line-height: 115%;">[7] “Lycopodiophyta.” //Pearson – Edurite//. Pearson Education Services, 2011. Web. 25 May. 2011. <span style="font-family: 'Calibri','sans-serif'; font-size: 13px; line-height: 115%;">[8] “Vascular System.” //Encyclopedia Britannica//. Web. 25 May. 2011. <span style="font-family: 'Calibri','sans-serif'; font-size: 13px; line-height: 115%;">[9] “Agricultural Botany.” //Saskschools//. Web. 26 May. 2011. <span style="font-family: 'Calibri','sans-serif'; font-size: 13px; line-height: 115%;">[10] Boskirk, Craig. “Phylum Lycophyta.” //Flora of Southwest Virginia//. Web. 26 May. 2011

//**By Sydney McCully & Elyssa Erickson**//