# Commelinids

In plant taxonomy, commelinids (originally commelinoids) is a clade of flowering plants within the monocots, distinguished by having cell walls containing ferulic acid. Well-known commelinids include palms and relatives (order Arecales), dayflowers, spiderworts, kangaroo paws, and water hyacinth (order Commelinales), grasses, bromeliads, rushes, and sedges (order Poales), ginger, cardamom, turmeric, galangal, bananas, plantains, and bird of paradise flower (order Zingiberales).
The commelinids are the only clade that the APG IV system 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 are the alismatid monocots and the lilioid monocots.

## Description

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

## Taxonomy and Phylogeny

The commelinids constitute a well-supported clade within the monocots, and this clade has been recognized in all four APG classification systems. It consists of four orders:
* Arecales (palms)
* Commelinales (spiderwort, water hyacinth)
* Poales (grasses, rushes, bromeliads)
* Zingiberales (gingers, banana)
| monocots 131 Acorales Alismatales 122 Petrosaviales 120 Dioscoreales 115 Pandanales 91 Liliales 121 121 Asparagales 120 commelinids 118 Arecales Poales Commelinales Zingiberales | Lilioid monocots Alismatid monocots |
As of APG IV (2016) the family Dasypogonaceae is no longer directly placed under commelinids but instead a family of order Arecales.

## Historical Taxonomy

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 Liliopsida (monocots). The name was also used in the 1981 Cronquist system. However, by the release of his 1980 system of classification, Takhtajan had merged this subclass into a larger one, and no longer considered it to be a clade.

### Takhtajan system

The Takhtajan system treated this as one of six subclasses within the class Liliopsida (=monocotyledons). It consisted of the following:
subclass Commelinidae      superorder Bromelianae            order Bromeliales            order Velloziales      superorder Pontederianae            order Philydrales            order Pontederiales            order Haemodorales      superorder Zingiberanae            order Musales            order Lowiales            order Zingiberales            order Cannales      superorder Commelinanae            order Commelinales            order Mayacales            order Xyridales            order Rapateales            order Eriocaulales      superorder Hydatellanae            order Hydatellales      superorder Juncanae            order Juncales            order Cyperales      superorder Poanae            order Flagellariales            order Restionales            order Centrolepidales            order Poales

### Cronquist system

The Cronquist system treated this as one of four subclasses within the class Liliopsida. It consisted of the following:
subclass Commelinidae      order Commelinales      order Eriocaulales      order Restionales      order Juncales      order Cyperales      order Hydatellales      order Typhales

### APG system

The APG II system does not use formal botanical names above the rank of order; most of the members were assigned to the clade commelinids in the monocots (its predecessor, the APG system used the clade commelinoids).