Frog-spoon-like

Frog-spoon-like
	Dragon root ( Calla palustris )
Systematics
Empire :	Plants (Plantae)
Department :	Vascular plants (tracheophyta)
Subdivision :	Seed plants (Spermatophytina)
Class :	Bedecktsamer (Magnoliopsida)
	Monocots
Order :	Frog-spoon-like
Scientific name
	Alismatales
	Dumort.

The frog-spoon-like (Alismatales) are an order of the monocotyledonous plants . Few species are medicinal or food plants . Varieties of a large number of species are used as ornamental plants in rooms, parks, gardens and ponds, aquariums and as cut flowers .

Description and locations

They are mostly perennial, rarely annual herbaceous plants with rhizomes . The vast majority of species grow terrestrially to epiphytically, this affects 90% of the species, for example the Tofieldiaceae and the most species-rich family of the Araceae with a wide range of life forms. 11 of the 13 families, but only 10% of the species, are swamp to aquatic plants in fresh, brackish to salt water. As an original feature, there are no tracheas or, in a primitive form, only in the roots . The mostly alternate, basal rosette leaves , rarely arranged in a whirling manner on the stems, are stalked or sessile. The leaf blades are lanceolate, oval to arrow-shaped. Except for the Araceae, there are small scales ("intravaginal scales", "squamulae") in the leaf sheaths.

The flowers stand together individually or in differently structured inflorescences . The hermaphroditic or unisexual flowers are usually threefold and radial symmetry . The flowers have many original features: stamens are either numerous (original) or in two, rarely only one circle of three (progressive). The gynoeceum is almost always choricarp with helically arranged, mostly upper carpels . The placentation is laminal to submarginal.

Follicles or nuts are formed from one carpel each .

The pollen grains are trinucleat. The green, nutrient-storing embryos and cotyledons ( cotyledons ) are great. In the seedlings, the hypocotyl and the roots are well developed. The endosperm is formed helobially. The anthers have a periplasmaltapetum with mononuclear tapetum cells. The polyandry has already been suggested as secondary.

Flower of Echinodorus isthmicus (Alismataceae).

The aquatic plant Aponogeton distachyos (Aponogetonaceae) with floating leaves.

Field with Xanthosoma sagittifolium. (Araceae).

The aquatic plant Blyxa echinosperma (Hydrocharitaceae).

The "seaweed" Zostera marina (Zosteraceae) often forms large populations anchored in the sand in shallow sea areas.

Systematics

The order of the Alismatales was established in 1829 by Barthélemy Charles Joseph Dumortier in an analysis of the Familles de Plantes (avec l'indication des principaux genres qui s'y rattachent. Imprimerie de J. Casterman, Tournay). In Hutchinson 1959 this order contained only three families. At Cronquist 1981 there were three more families.

The oldest fossils come from the Cretaceous (110 to 120 million years old).

The order of the frog-spoon-like (Alismatales) contains the following 14 families according to APG IV :

Arum family (Araceae)
Corn lily family (Tofieldiaceae)
Frog-spoon family (Alismataceae)
Swan flower family (Butomaceae)
Frog bite family (Hydrocharitaceae)
Rush Family (Scheuchzeriaceae)
Water ear plants (Aponogetonaceae)
Trident family (Juncaginaceae)
Maundiaceae
Seagrass (Zosteraceae)
Pondweed family (Potamogetonaceae)
Neptune grass family (Posidoniaceae)
Balaceae (Ruppiaceae)
Cymodoceaceae

The two families Acoraceae and Tofieldiaceae are at the base of the Alismatales and were not previously part of this group. Their exact family position is not yet certain. The remaining group, the "core alismatids", are divided into two monophyletic groups, which differ in their flower structure: the "petaloid" clade or Alismatales in the sense of Les & Tippery 2013, and the "tepaloid" clade or Potamogetonales in the sense by Les & Tippery 2013.

According to Les & Tippery 2013, the cladogram of the "core alismatids" looks like this:

Alismataceae

	Butomaceae

	Hydrocharitaceae

Aponogetonaceae

Scheuchzeriaceae

Juncaginaceae

	Cymodoceaceae clade 1

	Cymodoceaceae clade 2

	Ruppiaceae
Template: Klade / Maintenance / 3

Posidoniaceae

Maundiaceae

	Potamogetonaceae

	Zosteraceae

supporting documents

The order of the Alismatales on the AP website. (Section description)
Andreas Bresinsky , Christian Körner , Joachim W. Kadereit , Gunther Neuhaus , Uwe Sonnewald : Strasburger - Textbook of Botany , founded by Eduard Strasburger, Spektrum Akademischer Verlag, Heidelberg 2008, 36th edition ISBN 978-3-8274-1455-7 : Alismatales on pp. 853-855. (Section description)

Individual evidence

↑ The Angiosperm Phylogeny Group : An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG IV . Botanical Journal of the Linnean Society, 2016, Volume 181, pp. 1-20. doi: 10.1111 / boj.12385
↑ ^a ^b ^c Donald H. Les, Nicholas P. Tippery: In time and with water ... the systematics of alismatid monocotyledons . In: P. Wilkin, SJ Mayo: Early Events in Monocot Evolution . Cambridge University Press 2013, pp. 118-164.

Web links

Commons : Frog-Spoon-like (Alismatales) - Collection of images, videos and audio files

The families are online In: Wu Zheng-yi, Peter H. Raven, Deyuan Hong (Eds.): Flora of China . Volume 23: Acoraceae through Cyperaceae . Science Press / Missouri Botanical Garden Press, Beijing / St. Louis 2010, ISBN 978-1-930723-99-3 (English).