Alismatanae
William J. Hahn
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close boxIntroduction
The pondweeds and relatives are almost exclusively aquatic or marine and show numerous specializations for this habitat. Many of these features are reductions in form which have confounded attempts at phylogenetic resolution for the group (Dahlgren and Rasmussen, 1983; Les and Haynes, 1995). The superorder includes 15 families, 56 genera, and approximately 500 species.
Characteristics
Morphological synapomorphies for the alismatids include presence of intravaginal squamulae, lack of an endosperm, and root hair cells shorter than epidermal cells. (Dahlgren and Rasmussen, 1983; Dahlgren et al, 1985; Dalgren and Bremer, 1985).
Discussion of Phylogenetic Relationships
This reconstruction is taken from Les and Haynes (1995) and is based on rbcL data.
References
Dahlgren, RMT & K Bremer. 1985. Major clades of the angiosperms. Cladistics 1: 349-368.
Dahlgren, RMT, HT Clifford, & PF Yeo. 1985. The Families of the Monocotyledons. 520 pp. Springer-Verlag, Berlin.
Dahlgren, RMT, & F Rassmussen. 1983. Monocotyledon evolution. Characters and phylolgenetic estimation. Evol. Biol. 16: 255-395.
Les, DH & RR Haynes. 1995. Systematics of subclass Alismatidae: A synthesis of approaches. pp 353-377 in PJ Rudall, PJ Cribb, DF Cutler, & CJ Humphries (eds). Monocotyledons: systematics and evolution. Royal Botanic Garden, Kew.
Title Illustrations
| Scientific Name | Sagittaria montevidensis |
|---|---|
| Location | cultivated at Fairchild Tropical Botanic Garden, Miami, USA |
| Specimen Condition | Live Specimen |
| Body Part | flowers |
| Source | Sagittaria montevidensis male |
| Source Collection | Flickr |
| Image Use |
 This media file is licensed under the Creative Commons Attribution License - Version 2.0.
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| Copyright | © 2005 Scott |
| Scientific Name | Halophila ovalis |
|---|---|
| Location | Fly Point, Port Stephens, New South Wales, Australia |
| Specimen Condition | Live Specimen |
| Source | Broadleaf Seagrass |
| Source Collection | Flickr |
| Image Use |
This media file is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike License - Version 2.0.
|
| Copyright | © 2007 Richard Ling |
| Scientific Name | Butomus umbellatus |
|---|---|
| Location | Ithaca, New York, USA |
| Specimen Condition | Live Specimen |
| Body Part | flowers |
| Source | Prettiest rush ever... |
| Source Collection | Flickr |
| Image Use |
This media file is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike License - Version 2.0.
|
| Copyright | © 2007 Jenn Forman Orth |
About This Page
Georgetown University, Washington, D. C., USA
Correspondence regarding this page should be directed to William J. Hahn at
Page copyright © 1997
Page: Tree of Life
Alismatanae.
Authored by
William J. Hahn.
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Citing this page:
Hahn, William J. 1997. Alismatanae. Version 01 January 1997 (under construction). http://tolweb.org/Alismatanae/21329/1997.01.01 in The Tree of Life Web Project, http://tolweb.org/
