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Flowering plant

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Flowering plants
Scientific classification
Kingdom:Plantae
Division:Magnoliophyta
Classes
Magnoliopsida (dicots)
Liliopsida (monocots)
The flowering plants are one of the major groups of modern plants, comprising those whose seeds arise from structures called flowers. These are not always conspicuous, and many flowering plants are not often thought of as such. They first appeared at least 140 million years ago, during the Jurassic period, but may have diverged from the gymnosperms[?] in the earlier Triassic period.

Systematics

Flowering plants are usually treated as a division, sometimes called the Angiospermophyta or Anthophyta, but now more often called Magnoliophyta after the type genus Magnolia.

The classification of flowers has undergone considerable revision as ideas about their relationships change. That classification given by Arthur Cronquist[?] in the 1981 work An Integrated System of Classification of Flowering Plants is still used in many places, but since then many of the groups have been questioned. By now a general concensus has started to emerge about what the breakdown of the Magnoliophyta should look like, although there is still some variation. A typical version, called the Angiosperm Phylogeny Group system, can be found at the Missouri Botanical Garden (http://www.mobot.org/MOBOT/Research/APweb/welcome.html).

The main split among the flowers is between the dicotyledons and monocotyledons, called dicots and monocots for short. The name comes from the number of leaves within the seed, called cotyledons, but there are other notable differences (see how to distinguish a monocot from a dicot).

Most dicots belong to a group called the eudicots, but the dicot condition is primitive, and there are a few groups which are phylogenetically as close or closer to the monocots than to the eudicots. These comprise the following:

One division of the eudicots is as follows:

And the monocots are divided as follows:

Traditionally the dicots and monocots are treated as classes, formerly called the Dicotyledonae and Monocotyledonae, but now called the Magnoliopsida and Liliopsida according to the convention that classes and lower ranks must be named after type genera. In the Cronquist system, the basal dicots form a subclass, called the Magnoliidae[?]. In other systems, these are divided into one or more classes, while the eudicots are treated as a class Rosopsida or further divided.

The most common families of plants, in order of abundance, are:

  1. Asteraceae (daisy family): 25,000 species
  2. Orchidaceae (orchid family): 18,000
  3. Fabaceae (pea family): 17,000
  4. Poaceae (grass family): 9,000
  5. Rubiaceae (coffee family): 7,000
  6. Euphorbiaceae (spurge family): 5,000
  7. Cyperaceae[?] (rush family): 4,000

Functional groups

Plants may be organized according to their growth pattern:

Plants may also be organized according to how they are used. Food plants include fruits, vegetables, herbs, and spices.

References

wikipedia.org dumped 2003-03-17 with terodump