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Diatoms of the United States is now known as Diatoms of North America.
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(Round & Crawford) emended Rott, Kling & McGregor 2006      Category: Centric
TYPE SPECIES: Urosolenia eriensis (H.L. Smith) Round & Crawford in Round, Crawford & Mann



CLASS: Rhizosoleniophycidae
  ORDER: Rhizosoleniales
    FAMILY: Rhizosoleniaceae

  1. Frustules long, cylindrical
  2. One elongated spine per valve
  3. Frustules lightly silicified
  4. Valves joined by numerous scale-like copulae

Urosolenia includes small, centric species that are lightly silicified. Frustules typically lie in girdle view. One elongated spine extends from each valve face. Numerous scale-like copulae, or girdle bands, join the two shallow valves within a frustule.

Frustules of Urosolenia are fragile and are often destroyed by standard oxidative preparation for diatoms. Because of its fine structure, it is not often reported in surveys. Cells are best viewed live, or with burned mount prepartions. Urosolenia produces heavily silicified resting spores that may be preserved in sediments. The genus occurs commonly in shallow, eutrophic lakes.

Cite This Page:
Spaulding, S., and Edlund, M. (2008). Urosolenia. In Diatoms of the United States. Retrieved May 23, 2018, from

Contributor: Sarah Spaulding | Mark Edlund - December 2008


November 22nd, 2010 - Emended description

The genus Urosolenia was emended in 2006. The website was updated and reflects a change from: Urosolenia Round & Crawford in Round, Crawford & Mann to: Urosolenia (Round & Crawford) Rott, Kling & McGregor. The update was made by S. Spaulding.