Classification
Linnaeus's classification system greatly influenced eighteenth-century botany in America. Some of his students came over to categorize the species of the New World, most significantly Pehr Kalm, who traveled through the Great Lakes, the Mid-Atlantic colonies, and Canada, bringing back samples. Meanwhile, colonial settlers like John Bartram (1699–1777), Cadwallader Colden (1688–1776), Humphry Marshall (1722–1801), and others worked to incorporate the local flora into the work of Linnaeus, which provided a new sense of order for those working on studying the plants and animals of the overwhelmingly diverse and novel New World.
But although the Linnaean system was helpful, it could not survive the strain of the thousands of new discoveries in the Americas and Asia. Plant classifications based on reproduction resulted in categories that contained obviously widely diverging plants. In particular, Linnaeus was challenged by French botanists who emphasized grouping plants by shape (morphology). Antoine Laurent de Jussieu's (1748–1836) 1789 Genera Plantarum prompted the reorganizing of classification by appearance and added levels to the taxonomy.
The Jussieu modifications quickly, but not uncontroversially, became added to botanical literature, although the Linnaean system continued to be used in many prominent American publications through the early nineteenth century. Meanwhile, French botanists made other contributions to the study of North American plants. André Michaux (1746–1802) and his son, François André (1770–1855), traveled through much of eastern North America, from Canada to the Bahamas, observing and collecting. The end result of their massive researches was the 1803 Flora Boreali-Americana, the first large-scale compilation of North American plants. The work of the Michaux drew, not uncritically, on the reforms of Jussieu.
- For other meanings, see Botany (disambiguation)
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Botany is the scientific study of plant
Scope and importance of botany
As with other life forms in biology, plant life can be studied from different perspectives, from the molecular, genetic and biochemical level through organelles, cells, tissues, organs, individuals, plant populations, and communities of plants. At each of these levels a botanist might be concerned with the classification (taxonomy), structure (
Historically, botany covers all organisms that were not considered to be animals. Some of these "plant-like" organisms include fungi (studied in mycology), bacteria and viruses (studied in microbiology), and algae (studied in phycology). Most algae, fungi, and microbes are no longer considered to be in the plant kingdom. However, attention is still given to them by botanists, and bacteria, fungi, and algae are usually covered in introductory botany courses.
The study of plants has importance for a number of reasons. Plants are a fundamental part of life on Earth. They generate the oxygen, food, fibres, fuel and medicine that allow higher life forms to exist. Plants also absorb carbon dioxide through photosynthesis, a minor greenhouse gas that in large amounts can effect global climate. It is believed that the evolution of plants has changed the global atmosphere of the earth early in the earth's history and paleobotanists study ancient plants in the fossil record. A good understanding of plants is crucial to the future of human societies as it allows us to:
- Produce food to feed an expanding population
- Understand fundamental life processes
- Produce medicine and materials to treat diseases and other ailments
- Understand environmental changes more clearly
Human nutrition
Virtually all foods eaten come from plants, either directly from staple foods and other fruit and vegetables, or indirectly through livestock or other animals, which rely on plants for their nutrition. Plants are the fundamental base of nearly all food chains because they use the energy from the sun and nutrients from the soil and atmosphere and convert them into a form that can be consumed and utilized by animals, this is what ecologists call the first trophic level. Botanists also study how plants produce food we can eat and how to increase yields and therefore their work is important in mankind's ability to feed the world and provide food security for future generations, for example through plant breeding. Botanists also study weeds, plants which are considered to be a nuisance in a particular location. Weeds are a considerable problem in agriculture, and botany provides some of the basic science used to understand how to minimize 'weed' impact in agriculture and native ecosystems. Ethnobotany is the study of the relationships between plants and people.
Fundamental life processes
Plants are convenient organisms in which fundamental life processes (like cell division and protein synthesis for example) can be studied, without the ethical dilemmas of studying animals or humans. The genetic laws of inheritance were discovered in this way by Gregor Mendel, who was studying the way pea shape is inherited. What Mendel learned from studying plants has had far reaching benefits outside of botany. Additionally, Barbara McClintock discovered 'jumping genes' by studying maize. These are a few examples that demonstrate how botanical research has an ongoing relevance to the understanding of fundamental biological processes.
Medicine and materials
Many medicinal and recreational drugs, like cannabis, caffeine, and nicotine come directly from the plant kingdom. Others are simple derivatives of botanical natural products; for example aspirin is based on the pain killer salicylic acid which originally came from the bark of willow trees.[2] There may be many novel cures for diseases provided by plants, waiting to be discovered. Popular stimulants like coffee, chocolate, tobacco, and tea also come from plants. Most alcoholic beverages come from fermenting plants such as barley malt and grapes.
Plants also provide us with many natural materials, such as cotton, wood, paper, linen, vegetable oils, some types of rope, and rubber. The production of silk would not be possible without the cultivation of the mulberry plant. Sugarcane, rapeseed, soy and other plants with a highly-fermentable sugar or oil content have recently been put to use as sources of biofuels, which are important alternatives to fossil fuels, see biodiesel.
Modern botany
A considerable amount of new knowledge today is being generated from studying model plants like Arabidopsis thaliana. This weedy species in the mustard family was one of the first plants to have its genome sequenced. The sequencing of the rice (Oryza sativa) genome and a large international research community have made rice the de facto cereal/grass/monocot model. Another grass species, Brachypodium distachyon is also emerging as an experimental model for understanding the genetic, cellular and molecular biology of temperate grasses. Other commercially-important staple foods like wheat, maize, barley, rye, pearl millet and soybean are also having their genomes sequenced. Some of these are challenging to sequence because they have more than two haploid (n) sets of chromosomes, a condition known as polyploidy, common in the plant kingdom. Chlamydomonas reinhardtii (a single-celled, green alga) is another plant model organism that has been extensively studied and provided important insights into cell biology.
In 1998 the Angiosperm Phylogeny Group published a phylogeny of flowering plants based on an analysis of DNA sequences from most families of flowering plants. As a result of this work, major questions such as which families represent the earliest branches in the genealogy of angiosperms are now understood. Investigating how plant species are related to each other allows botanists to better understand the process of evolution in plants.
Subdisciplines of Botany
- Agronomy—Application of plant science to crop production
- Bryology—Mosses, liverworts, and hornwarts
- Economic botany—The place of plants in economics
- Ethnobotany—Relationship between humans and plants
- Forestry—Forest management and related studies
- Horticulture—Cultivated plants
- Paleobotany—Fossil plants
- Palynology—Pollen and spores
- Phycology - Algae
- Phytochemistry—Plant secondary chemistry and chemical processes
- Phytopathology—Plant diseases
Plant anatomy —Cell and tissue structure- Plant ecology—Role of plants in the environment
- Plant genetics—Genetic inheritance in plants
Plant morphology —Structure and life cycles- Plant physiology—Life functions of plants
- Plant systematics—Classification and naming of plants
See also
| Botany | |
|---|---|
| Subdisciplines of botany | Ethnobotany · Paleobotany · |
| Plants | Evolutionary history of plants · Algae · Bryophyte · Pteridophyte · Gymnosperm · Angiosperm |
| Plant parts | Flower · Fruit · Leaf · Meristem · Root · Stem · Stoma · Vascular tissue · Wood |
| Plant cells | Cell wall · Chlorophyll · Chloroplast · Photosynthesis · |
| Plant life cycles | Gametophyte · Plant sexuality · Pollen · Pollination · Seed · Spore · Sporophyte |
| Plant taxonomy | Botanical name · Botanical nomenclature · Herbarium · IAPT · ICBN · Species |
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