Plants Encyclopedia

Please help improve this section by adding citations to reliable sources. Like all other organisms, plants are made up of cells, which are semi-autonomous units consisting of protoplasts surrounded by a special layer of lipids and proteins, termed the plasma membrane.

Plant Information and Pictures

Coal and petroleum are fossil substances of plant origin. Lateral meristems are parallel to the elongation axis of the shoots and roots, and are responsible for thickening of the plant. Plants are often the dominant physical and structural component of habitats where they occur. This tree with fern-like foliage and a trunk with conifer-like wood was heterosporous producing spores of two different sizes, an early step in the evolution of seeds.

Navigation menu

Lycopods are most abundant in the tropics, although numerous species of Lycopodium ground pine grow in woodlands in the temperate zone. The major plant hormones are auxins, gibberellins, cytokinins, abscissic acid, and ethylene. Generale Morphologie der Organismen.

Undoubtedly, as our knowledge of evolution and biological diversity increases, Whittaker's five kingdom classification system will require further modification. The xylem moves water and minerals from the root to the rest of the plant, and the phloem provides the roots with sugars and other nutrient produced by the leaves. The diploid organism produces haploid spores that germinate to form the haploid organism. In other projects Wikimedia Commons Wikispecies Wikiquote. All embryophytes and most thallophytes have a life cycle in which there are two alternating generations see reproduction.

Plants encyclopedia

The integument becomes a seed coat, and the ovule develops into a seed. Streptofilum Klebsormidiophyceae. Evergreen Broadleaf Shrub Click Here for more details and pictures. Genes are connected together into chromosomes, thread-like structures that occur in a characteristic number in each species.

Plants encyclopedia

Plant structure

This chert preserved early plants in cellular detail, petrified in volcanic springs. The list below contains the most recently viewed plants in our database. Plants can be so crowded that no single individual produces normal growth, causing etiolation and chlorosis. From Wikipedia, production planning and control with sap erp the free encyclopedia.

Horticulture and gardening. Plants are often used as memorials, gifts and to mark special occasions such as births, deaths, weddings and holidays. Archaeplastida Glaucophyta Rhodophyta Picozoa. Viruses are spread by contaminated seeds and sucking insects aphids, leafhoppers, thrips that act as carriers of the virus.

Online Plant Guide Search

The bacteria enter the plant through natural openings, like the stomata of the leaves, or through wounds in the plant tissue. Plants have some of the largest genomes among all organisms. The gametophyte phase is dominant, and in mosses this is the familiar, small, green, leafy plant.

The sporophyte phase is dominant, and is the familiar, low-growing, green plant in many species which superficially resembles the branch of a pine. As the seedling grows, it begins to produce chlorophyll and turn green. The table below shows some species count estimates of different green plant Viridiplantae divisions. Plant Physiological Ecology. Anthocerotophyta hornworts.

Charophytes basal Streptofilum Klebsormidiophyceae. Plants in a broad sense comprise the green plants listed above plus the red algae Rhodophyta and the glaucophyte algae Glaucophyta that store Floridean starch outside the plastids, in the cytoplasm. The membranes of the endoplasmic reticulum are often continuous with the plasma membrane, the outer nuclear membrane, the tonoplast, and Golgi bodies.

The genome of a plant controls its growth. Apical meristems are at the tips of shoots and roots, and are responsible for elongation of a plant. Plants that are annual in alpine or temperate regions can be biennial or perennial in warmer climates. Hemiepiphytes like the strangler fig begin as epiphytes but eventually set their own roots and overpower and kill their host. Seed plants can survive and reproduce in extremely arid conditions, because they are not dependent on free water for the movement of sperm, or the development of free living gametophytes.

Plant diseases can be infectious transmitted from plant to plant or noninfectious. Cite this article Pick a style below, and copy the text for your bibliography. The Classification of Lower Organisms. Many regions of the endoplasmic reticulum have ribosomes associated with them. Mosses are particularly prominent in the northern boreal forest and arctic and alpine tundra.

Plants encyclopediaPlants encyclopedia

The freshwater stoneworts strongly resemble land plants and are believed to be their closest relatives. Plants that produce windblown pollen invoke allergic reactions in people who suffer from hay fever. This dehydration is now considered the fundamental cause of freezing injury.

Learn more about citation styles Citation styles Encyclopedia. Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia. Ferns reproduce by making spores, and they are mostly restricted to moist environments so their sperm can swim to reach the eggs. Azaleas and Rhododendrons. Die systematische Phylogenie.

Plants encyclopedia

They also have roots for taking up water and minerals. It is an erect stem, with whorls of microphylls, and a spore-producing, cone-like structure, termed a strobilus, on top. However, these organisms are still often considered plants, particularly in popular contexts. However, seed plants, the most advanced of the land plants, have a greatly reduced gametophyte, and a dominant sporophyte. Charophyceae Coleochaetophyceae Zygnematophyceae Mesotaeniaceae.

Male reproductive structures produce pollen grains, or male gametophytes, which travel by wind to the female reproductive structures. Cytokinins promote cell division and organ development, but impede senescence. Many of these chemicals form the bases for the development of drugs. Cell division is also characterized by the development of a phragmoplast for the construction of a cell plate in the late stages of cytokinesis. Grace Communications Foundation.

Plants are classified into twelve phyla sometimes called divisions in two major groups. Plants grown as industrial crops are the source of a wide range of products used in manufacturing, sometimes so intensively as to risk harm to the environment. The plasma membrane regulates transport of various molecules into and out of the cell, and also serves as a sort of two-dimensional scaffolding, upon which many biochemical reactions occur. Land plants appear to have evolved from photosynthetic, aquatic ancestors about million years ago, probably from the Chlorophyta, or green algae. The nucleus is often considered to be the control center of a cell.

See also the list of plant orders. In contrast, most other algae e. Many conifers are used for lumber, paper, and other important products.