Search results
Results from the WOW.Com Content Network
The dicotyledons, also known as dicots (or, more rarely, dicotyls), [2] are one of the two groups into which all the flowering plants (angiosperms) were formerly divided. The name refers to one of the typical characteristics of the group: namely, that the seed has two embryonic leaves or cotyledons .
The monocots or monocotyledons have, as the name implies, a single (mono-) cotyledon, or embryonic leaf, in their seeds.Historically, this feature was used to contrast the monocots with the dicotyledons or dicots which typically have two cotyledons; however, modern research has shown that the dicots are not a natural group, and the term can only be used to indicate all angiosperms that are not ...
Among plants, dicotyledons (in the traditional sense) are paraphyletic because the group excludes monocotyledons. "Dicotyledon" has not been used as a botanic classification for decades, but is allowed as a synonym of Magnoliopsida. [note 1] Phylogenetic analysis indicates that the monocots are a development from a dicot ancestor. Excluding ...
One of the modern systems of plant taxonomy, the Dahlgren system was published by monocot specialist Rolf Dahlgren in 1975 [1] and revised in 1977, [2] and 1980. [3] However, he is best known for his two treatises on monocotyledons in 1982 [4] and revised in 1985. [5] His wife Gertrud Dahlgren continued the work after his death. [6]
The two classes of flowering plants (angiosperms) are distinguished by their numbers of seed leaves: monocotyledons (monocots) have one blade-shaped cotyledon, whereas dicotyledons (dicots) possess two round cotyledons. Gymnosperms are more varied. For example, pine seedlings have up to eight cotyledons. The seedlings of some flowering plants ...
This fixed the position of Gymnosperms as a class distinct from Dicotyledons, and the term Angiosperm then, gradually, came to be accepted as the suitable designation for the whole of the flowering plants (other than Gymnosperms), including the classes of Dicotyledons and Monocotyledons. [4] This is the sense in which the term is used, today. [5]
There are 27 families of flowering plants whose earliest ancestors diverged from what became the two most prominent groups of flowering plants, the eudicots and monocots. [1] [a] They are quite diverse, with woody and non-woody plants, evergreen and deciduous shrubs and trees, and plants that grow in soil, in water and on other plants.
Above the rank of order, these systems use their own names, such as angiosperms, eudicots, monocots, rosids, etc. These names refer to clades (unranked). The class Magnoliopsida is not defined. The idea that dicotyledons are a taxonomic unit and require a formal name is rejected by the APG: the dicots are considered to be paraphyletic.