In plant taxonomy, commelinids (originally commelinoids) (plural, not capitalised) is a name used by the APG IV system for a clade within the monocots, which in its turn is a clade within the angiosperms. The commelinids are the only clade that the APG has informally named within the monocots. The remaining monocots are a paraphyletic unit. Also known as the commelinid monocots it forms one of three groupings within the monocots, and the final branch, the other two groups being the alismatid monocots and the lilioid monocots. 

Members of the commelinid clade have cell walls containing UV-fluorescent ferulic acid. 

The commelinids were first recognized as a formal group in 1967 by Armen Takhtajan, who named them the Commelinidae and assigned them to a subclass of the monocots. However, by the release of his 1980 system of classification, he had merged this subclass into a larger one no longer considered to be a clade. 

The commelinids constitute a well-supported clade within the monocots, and this clade has been recognized in all four APG classification systems. 

The commelinids of APG II (2003) and APG III (2009) contain essentially the same plants as the commelinoids of the earlier APG system (1998). In APG IV (2016) the family Dasypogonaceae is no longer directly placed under commelinids but instead a family of order Arecales.
what is the article about?
what were they originally called?
when were they first known?
by?
what did he call them?
what family is not in commelinids now?
under what is it?
did Armen subclass them?
what was that?
when did he change this?
what did he do then?
what do cell walls contain?
is commelinoids plural?
how many groupings are in the monocots?
are they the only clade named in the monocots?
what kind are the remaining?
does it have more groups?
how many?
what are they called?
what system is used in the article?
commelinids
commelinids
commelinoids
commelinoids
1967
1967
Armen Takhtajan
Armen Takhtajan
Commelinidae
Commelinidae
Dasypogonaceae
Dasypogonaceae 
order Arecales.
order Arecales.
yes
assigned them to a subclass of the monocots.
monocots
monocots
1980
1980
merged this subclass into a larger one
merged this subclass into a larger one
UV-fluorescent ferulic acid
UV-fluorescent ferulic acid
yes
plural, not capitalised
three
 three
yes
The commelinids are the only clade that the APG has informally named within the monocots.
paraphyletic unit
paraphyletic unit
yes
the other two groups being
two
two
alismatid monocots and the lilioid monocots.
alismatid monocots and the lilioid monocots. 
APG IV system
 APG IV system