Dicotyledon

Dicotyledon
Lamium album (white dead nettle)
Lamium album (white dead nettle)
Scientific classificationEdit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Spermatophytes
Clade: Angiosperms
Groups included
Cladistically included but traditionally excluded taxa
Synonyms
Dicotyledon plantlet
Young castor oil plant showing its prominent two embryonic leaves (cotyledons), which differ from the adult leaves

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. There are around 200,000 species within this group.[3] The other group of flowering plants were called monocotyledons (or monocots), typically each having one cotyledon. Historically, these two groups formed the two divisions of the flowering plants.

Largely from the 1990s onwards, molecular phylogenetic research confirmed what had already been suspected: that dicotyledons are not a group made up of all the descendants of a common ancestor (i.e., they are not a monophyletic group). Rather, a number of lineages, such as the magnoliids and groups now collectively known as the basal angiosperms, diverged earlier than the monocots did; in other words, monocots evolved from within the dicots, as traditionally defined. The traditional dicots are thus a paraphyletic group.[4]

The eudicots are the largest monophyletic group within the dicotyledons. They are distinguished from all other flowering plants by the structure of their pollen. Other dicotyledons and the monocotyledons have monosulcate pollen (or derived forms): grains with a single sulcus. Contrastingly, eudicots have tricolpate pollen (or derived forms): grains with three or more pores set in furrows called colpi.

  1. ^ Cite error: The named reference Takh64 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference TFD was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Hamilton2006 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Simp11 was invoked but never defined (see the help page).