Alismatales

Last updated

Alismatales
AlismaPlant1.jpg
Alisma plantago-aquatica
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Alismatales
R.Br. ex Bercht. & J.Presl [1]
Families

See Taxonomy

Snake lily (Dracunculus vulgaris) of family Araceae in Crete, Greece. 044 Dracunculus vulgaris at Akrotiri peninsula, Crete, Greece.jpg
Snake lily ( Dracunculus vulgaris ) of family Araceae in Crete, Greece.
Ottelia alismoides from family Hydrocharitaceae in Hyderabad, India. Ottelia alismoides W IMG 0915.jpg
Ottelia alismoides from family Hydrocharitaceae in Hyderabad, India.

The Alismatales (alismatids) are an order of flowering plants including about 4,500 species. Plants assigned to this order are mostly tropical or aquatic. Some grow in fresh water, some in marine habitats. Perhaps the most important food crop in the order is the taro plant, Colocasia esculenta.

Contents

Description

The Alismatales comprise herbaceous flowering plants of often aquatic and marshy habitats, and the only monocots known to have green embryos other than the Amaryllidaceae. They also include the only marine angiosperms growing completely submerged, the seagrasses. [2] The flowers are usually arranged in inflorescences, and the mature seeds lack endosperm.

Both marine and freshwater forms include those with staminate flowers that detach from the parent plant and float to the surface. There they can pollinate carpellate flowers floating on the surface via long pedicels. [3] In others, pollination occurs underwater, where pollen may form elongated strands, increasing chance of success. Most aquatic species have a totally submerged juvenile phase, and flowers are either floating or emerge above the water's surface. Vegetation may be totally submersed, have floating leaves, or protrude from the water. Collectively, they are commonly known as "water plantain". [4]

Taxonomy

The Alismatales contain about 165 genera in 13 families, with a cosmopolitan distribution. Phylogenetically, they are basal monocots, diverging early in evolution relative to the lilioid and commelinid monocot lineages. [5] Together with the Acorales, the Alismatales are referred to informally as the alismatid monocots. [6]

Early systems

The Cronquist system (1981) places the Alismatales in subclass Alismatidae, class Liliopsida [= monocotyledons] and includes only three families as shown:

Cronquist's subclass Alismatidae conformed fairly closely to the order Alismatales as defined by APG, minus the Araceae.

The Dahlgren system places the Alismatales in the superorder Alismatanae in the subclass Liliidae [= monocotyledons] in the class Magnoliopsida [= angiosperms] with the following families included:

In Tahktajan's classification (1997), the order Alismatales contains only the Alismataceae and Limnocharitaceae, making it equivalent to the Alismataceae as revised in APG-III. Other families included in the Alismatates as currently defined are here distributed among 10 additional orders, all of which are assigned, with the following exception, to the Subclass Alismatidae. Araceae in Tahktajan 1997 is assigned to the Arales and placed in the Subclass Aridae; Tofieldiaceae to the Melanthiales and placed in the Liliidae. [7]

Angiosperm Phylogeny Group

The Angiosperm Phylogeny Group system (APG) of 1998 and APG II (2003) assigned the Alismatales to the monocots, which may be thought of as an unranked clade containing the families listed below. The biggest departure from earlier systems (see below) is the inclusion of family Araceae. By its inclusion, the order has grown enormously in number of species. The family Araceae alone accounts for about a hundred genera, totaling over two thousand species. The rest of the families together contain only about five hundred species, many of which are in very small families. [8]

The APG III system (2009) differs only in that the Limnocharitaceae are combined with the Alismataceae; it was also suggested that the genus Maundia (of the Juncaginaceae) could be separated into a monogeneric family, the Maundiaceae, but the authors noted that more study was necessary before the Maundiaceae could be recognized. [1]

In APG IV (2016), it was decided that evidence was sufficient to elevate Maundia to family level as the monogeneric Maundiaceae. [8] The authors considered including a number of the smaller orders within the Juncaginaceae, but an online survey of botanists and other users found little support for this "lumping" approach. [9] Consequently, the family structure for APG IV is:

Cladogram of Alismatales [2]
Alismatales

Phylogeny

Cladogram showing the orders of monocots (Lilianae sensu Chase & Reveal) [10] based on molecular phylogenetic evidence:

Alismatid monocots

Related Research Articles

<span class="mw-page-title-main">Arecales</span> Order of flowering plants

Arecales is an order of flowering plants. The order has been widely recognised only for the past few decades; until then, the accepted name for the order including these plants was Principes.

<span class="mw-page-title-main">Dioscoreales</span> Order of lilioid monocotyledonous flowering plants

The Dioscoreales are an order of monocotyledonous flowering plants, organized under modern classification systems, such as the Angiosperm Phylogeny Group or the Angiosperm Phylogeny Web. Among monocot plants, Dioscoreales are grouped with the lilioid monocots, wherein they are a sister group to the Pandanales. In total, the order Dioscoreales comprises three families, 22 genera and about 850 species.

<span class="mw-page-title-main">Liliales</span> Order of monocot flowering plants, including lilies

Liliales is an order of monocotyledonous flowering plants in the Angiosperm Phylogeny Group and Angiosperm Phylogeny Web system, within the lilioid monocots. This order of necessity includes the family Liliaceae. The APG III system (2009) places this order in the monocot clade. In APG III, the family Luzuriagaceae is combined with the family Alstroemeriaceae and the family Petermanniaceae is recognized. Both the order Lililiales and the family Liliaceae have had a widely disputed history, with the circumscription varying greatly from one taxonomist to another. Previous members of this order, which at one stage included most monocots with conspicuous tepals and lacking starch in the endosperm are now distributed over three orders, Liliales, Dioscoreales and Asparagales, using predominantly molecular phylogenetics. The newly delimited Liliales is monophyletic, with ten families. Well known plants from the order include Lilium (lily), tulip, the North American wildflower Trillium, and greenbrier.

<span class="mw-page-title-main">Monocotyledon</span> Clade of flowering plants

Monocotyledons, commonly referred to as monocots, are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of the major groups into which the flowering plants have traditionally been divided; the rest of the flowering plants have two cotyledons and are classified as dicotyledons, or dicots.

The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in a series of monographs and texts, including The Evolution and Classification of Flowering Plants and An Integrated System of Classification of Flowering Plants (1981).

<i>Acorus</i> Genus of aquatic plants

Acorus is a genus of monocot flowering plants. This genus was once placed within the family Araceae (aroids), but more recent classifications place it in its own family Acoraceae and order Acorales, of which it is the sole genus of the oldest surviving line of monocots. Some older studies indicated that it was placed in a lineage, that also includes aroids (Araceae), Tofieldiaceae, and several families of aquatic monocots. However, modern phylogenetic studies demonstrate that Acorus is sister to all other monocots. Common names include calamus and sweet flag.

<span class="mw-page-title-main">Potamogetonaceae</span> Family of aquatic plants

The Potamogetonaceae, commonly referred to as the pondweed family, is an aquatic family of monocotyledonous flowering plants. The roughly 110 known species are divided over six genera. The largest genus in the family by far is Potamogeton, which contains about 100 species.

<span class="mw-page-title-main">Zosteraceae</span> Family of aquatic plants

Zosteraceae is a family of marine perennial flowering plants found in temperate and subtropical coastal waters, with the highest diversity located around Korea and Japan. Most seagrasses complete their entire life cycle under water, having filamentous pollen especially adapted to dispersion in an aquatic environment and ribbon-like leaves that lack stomata. Seagrasses are herbaceous and have prominent creeping rhizomes. A distinctive characteristic of the family is the presence of characteristic retinacules, which are present in all species except members of Zostera subgenus Zostera.

Alismatidae is a botanical name at the rank of subclass. Circumscription of the subclass will vary with the taxonomic system being used ; the only requirement being that it includes the family Alismataceae. It is a relatively new name: earlier systems, such as the Engler and Wettstein systems, used the name Helobiae for a comparable unit.

<span class="mw-page-title-main">Juncaginaceae</span> Family of aquatic plants

Juncaginaceae is a family of flowering plants, recognized by most taxonomists for the past few decades. It is also known as the arrowgrass family. It includes 3 genera with a total of 34 known species.

<span class="mw-page-title-main">Commelinids</span> Clade of monocot flowering plants

In plant taxonomy, commelinids is a clade of flowering plants within the monocots, distinguished by having cell walls containing ferulic acid.

The Kubitzki system is a system of plant taxonomy devised by Klaus Kubitzki, and is the product of an ongoing survey of vascular plants, entitled The Families and Genera of Vascular Plants, and extending to 15 volumes in 2018. The survey, in the form of an encyclopedia, is important as a comprehensive, multivolume treatment of the vascular plants, with keys to and descriptions of all families and genera, mostly by specialists in those groups. The Kubitzki system served as the basis for classification in Mabberley's Plant-Book, a dictionary of the vascular plants. Mabberley states, in his Introduction on page xi of the 2008 edition, that the Kubitzki system "has remained the standard to which other literature is compared".

<span class="mw-page-title-main">Najadales</span> Order of flowering plants

Najadales is the botanical name of an order of flowering plants. A well-known system that used this name is the Cronquist system (1981), which used this name for an order in subclass Alismatidae with this circumscription:

<span class="mw-page-title-main">Cymodoceaceae</span> Family of aquatic plants

Cymodoceaceae is a family of flowering plants, sometimes known as the "manatee-grass family", which includes only marine species.

<span class="mw-page-title-main">Tofieldiaceae</span> Family of flowering plants

Tofieldiaceae is a family of flowering plants in the monocot order Alismatales. The family is divided into four genera, which together comprise 28 known species. They are small, herbaceous plants, mostly of arctic and subarctic regions, but a few extend further south, and one genus is endemic to northern South America and Florida. Tofieldia pusilla is sometimes grown as an ornamental.

<i>Butomus</i> Genus of flowering plants

Butomus is the only known genus in the plant family Butomaceae, native to Europe and Asia. It is considered invasive in some parts of the United States.

<span class="mw-page-title-main">Lilioid monocots</span> Grade of flowering plant orders, within Lilianae

Lilioid monocots is an informal name used for a grade of five monocot orders in which the majority of species have flowers with relatively large, coloured tepals. This characteristic is similar to that found in lilies ("lily-like"). Petaloid monocots refers to the flowers having tepals which all resemble petals (petaloid). The taxonomic terms Lilianae or Liliiflorae have also been applied to this assemblage at various times. From the early nineteenth century many of the species in this group of plants were put into a very broadly defined family, Liliaceae sensu lato or s.l.. These classification systems are still found in many books and other sources. Within the monocots the Liliaceae s.l. were distinguished from the Glumaceae.

<i>Maundia</i> Genus of flowering plants

Maundia is a genus of alismatid monocots, described in 1858. Maundia was formerly included in the family Juncaginaceae but is now considered to form a family of its own under the name Maundiaceae. It contains only one known species, Maundia triglochinoides, endemic to Australia.

<span class="mw-page-title-main">Alismatid monocots</span> Grade of flowering plant orders within Lilianae

Alismatid monocots is an informal name for a group of early branching monocots, consisting of two orders, the Acorales and Alismatales. The name has also been used to refer to the Alismatales alone. Monocots are frequently treated as three informal groupings based on their branching from ancestral monocots and shared characteristics: alismatid monocots, lilioid monocots and commelinid monocots. Research at the Royal Botanical Gardens, Kew is organised into two teams I: Alismatids and Lilioids and II: Commelinids. A similar approach is taken by Judd in his Plant systematics.

References

  1. 1 2 Angiosperm Phylogeny Group (2009), "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III", Botanical Journal of the Linnean Society, 161 (2): 105–121, doi: 10.1111/j.1095-8339.2009.00996.x , hdl: 10654/18083
  2. 1 2 Stevens, P.F. (2022). "Alismatales". Angiosperm Phylogeny Website . 14. Missouri Botanical Garden . Retrieved 28 October 2022.
  3. Sullivan, G. & Titus, J.E. (1996). "Physical site characteristics limit pollination and fruit set in the dioecious hydrophilous species, Vallisneria americana". Oecologia. 108 (2): 285–292. Bibcode:1996Oecol.108..285S. doi:10.1007/BF00334653. PMID   28307841. S2CID   13369438.
  4. "-Alismatales (Water Plantains)" (PDF). Archived from the original (PDF) on 12 June 2010. Retrieved 27 May 2010.
  5. Wilkin & Mayo 2013.
  6. RBG 2010.
  7. "-Flowering Plant Gateway". Archived from the original on 6 October 2011. Retrieved 27 May 2010.
  8. 1 2 APG IV 2016.
  9. Christenhusz et al. (2015)
  10. 1 2 Chase & Reveal 2009.

Further reading