Suaedoideae

Suaedoideae
Suaeda nigra
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Core eudicots
Order:	Caryophyllales
Family:	Amaranthaceae
Subfamily:	Suaedoideae Ulbr.
Genera
about 2 genera, see text

The Suaedoideae are a subfamily of plants in the Amaranthaceae family (now including the former Chenopodiaceae family).

Description

The Suaedoideae have well-developed leaves. Except for genus Bienertia, the leaves show a central and many lateral vascular bundles. The leaves are neither decurrent nor amplexicaul.

The inflorescences are axillary cymes. The flowers are sitting free in the axils of bracts, with lateral bracteoles. The perianth consists of 5 tepals, which are more or less fused basally. 5 stamens are present. The seed encloses a spiral embryo, mostly without any perisperm.

Distribution

The Suaedoideae have a nearly worldwide distribution. They are important members of the vegetation of shores and salty inland habitats. They are especially common in dry (arid) regions.

Photosynthesis pathway

Among the species of Suaedoideae, there are nearly equal numbers of C₃-plants and C₄-plants. During the evolution of the subfamily, the C₄-photosynthesis pathway seems to have been derived from four independent origins: two times with Kranz C₄ anatomy in Suaeda section Salsina and Suaeda section Schoberia. Two independent origins of non-Kranz C₄ systems are found in Bienertia and Suaeda section Borszczowia. In these plants, the photosynthesis pathways are located without spatial separation in a "single cell C₄" type.^[1]

Systematics

Habitat of Bienertia sinuspersici

Suaeda maritima

According to phylogenetic research by Kapralov et al. (2006), the Suaedoideae are grouped in 2 tribes:

• Tribus Bienertieae Ulbr., with only one genus:
  • Bienertia Bunge ex Boiss., with 3 species:
    • Bienertia cycloptera Bunge ex Boiss.^[2]
    • Bienertia sinuspersici Akhani^[3]
    • Bienertia kavirense Akhani ^[4]
• Tribus Suaedeae, with only one genus:
  • Suaeda Forssk. ex J.F.Gmel. (inclusive Alexandra Bunge and Borszczowia Bunge). With about 82 species, nearly worldwide. The genus can be further divided:
    • subgenus Brezia (Moq.) Freitag & Schütze^[5]
      • section Brezia (Moq.) Volk
    • subgenus Suaeda
      • section Alexandra (Bunge) Kapralow et al.
      • section Borszczowia (Bunge) Freitag & Schütze^[5]
      • section Physophora Iljin
      • section Salsina Moq. s.l. (sensu Schütze et al.)^[5]
      • section Schanginia (C.A.Meyer) Volk
      • section Schoberia (C.A.Meyer) Volk
      • section Suaeda

See also

• Halophyte

References

• Maxim V. Kapralov, Hossein Akhani, Elena V. Voznesenskaya, Gerald Edwards, Vincent Franceschi, Eric H. Roalson (2006): Phylogenetic Relationships in the Salicornioideae / Suaedoideae / Salsoloideae s.l. (Chenopodiaceae) Clade and a Clarification of the Phylogenetic Position of Bienertia and Alexandra Using Multiple DNA Sequence Datasets. Systematic Botany volume 31(3), p. 571–585. (chapters description, distribution, systematics)

1. Gudrun Kadereit, Thomas Borsch, K. Weising, und Helmut Freitag (2003): Phylogeny of Amaranthaceae and Chenopodiaceae and the evolution of C₄ photosynthesis. - Int. J. Plant Sci. 164(6), p 959–986.
2. Akhani H, Ghobadnejhad M, Hashemi SMH (2003) Ecology, biogeography and pollen morphology of Bienertia cycloptera Bunge ex Boiss. (Chenopodiaceae), an Enigmatic C-4 plant without Kranz anatomy. Plant Biology 5(2):167-178.
3. Akhani H, Barroca J, Koteeva N, Voznesenskaya E, Franceschi V, Edwards G, Ghaffari SM, Ziegler H (2005) Bienertia sinuspersici (Chenopodiaceae): A new species from southwest Asia and discovery of a third terrestrial C4 plant without Kranz anatomy. Systematic Botany 30(2):290-301.
4. Akhani, H, Chatrenoor T, Dehghani M, Khoshravesh, R, Mahdavi, P. and Z. Matinzadeh. 2012. A new species of Bienertia (Chenopodiaceae) from Iranian salt deserts: a third species of the genus and discovery of a fourth terrestrial C4 plant without Kranz anatomy. Plant Biosystems 146: 550-559. DOI:10.1080/11263504.2012.662921.
5. P. Schütze, Helmut Freitag & K. Weising (2003): An integrated molecular and morphological study of the subfamily Suaedoideae Ulbr. (Chenopodiaceae), In: Plant Systematics and Evolution, Volume 239, p. 257-286: Abstract.

External links