Achnanthes
Bory 1927 Category: Monoraphid
TYPE SPECIES: Achnanthes adnata Bory
Image Credit: Mark Edlund
CLASS: Bacillariophyceae
ORDER: Achnanthales
FAMILY: Achnanthaceae
- Frustules heterovalvar - one valve with a raphe, the other lacking a raphe
- Raphe valve usually possesses a fascia or stauros
- Valves shallow and arched in girdle view
- Rapheless valve without fascia, narrower sternum usually off center
The frustules of Achnanthes are heterovalvar. The raphe valve usually possesses a central area of thickened silica, called a fascia or stauros. The rapheless valve has no such central area and the sternum may be positioned near the valve margin. In girdle view, the mantle of the rapheless valve appears to be more ornamented than that of the raphe valve. The striae are uni-, bi-, or triseriate and composed of areolae covered by complex cribra, or sieve plates.
Cells may grow alone, or may form short chains. Living cells are usually attached to substrata by a mucilage stalk extending through one end of the raphe valve. Most species are found in marine habitats, but a few taxa occur inland including Achnanthes coarctata. Inland species are commonly associated with mosses and lichens in aerophillic habitats. Many common species previously classified in this genus are now recognized as species of Achnanthidium, Psammothidium, Planothidium, and other genera.
Cite This Page:
Spaulding, S., and Edlund, M. (2008). Achnanthes. In Diatoms of the United States. Retrieved May 19, 2013, from http://westerndiatoms.colorado.edu/taxa/genus/Achnanthes
Contributor: Sarah Spaulding | Mark Edlund - July 2008
Reviewer: Sam Rushforth
Citations
Boyle, J.A., Pickett-Heaps, J.D. and D.B. Czarnecki. (1984). Valve morphogenesis in the pennate diatom Achnanthes coarctata. Journal of Phycology 20(4): 563-573.
Cox, E.J. (2006). Achnanthes sensu stricto belongs with genera of the Mastogloiales rather than with other monoraphid diatoms (Bacillariophyta). European Journal of Phycology 41(1): 67-81. 10.1080/09670260500491543
Hamilton, P.B., Poulin, M. and Kingston, J.C. (1993). A taxonomic and morphological study of an acidobiontic diatom, Neidium holstii (Cleve) Krammer from North America and Greenland. Nova Hedwigia, Beihefte 106: 109-119.
Kingston, J.C. (2003). Araphid and Monoraphid Diatoms. In: Freshwater Algae of North America. Ecology and Classification (J.D. Wehr and R.G. Sheath, eds). Elsevier Science pp. 595-636.
Lange-Bertalot, H. (1997). Revision of the genus Achnanthes sensu lato (Bacillariophyceae): Achnantheiopsis, a new genus with the type species A. lanceolata. Archiv fur Protistenkunde 148: 199-208.
Lange-Bertalot, H. (1999). Neue Kombinationen von taxa aus Achnanthes Bory (sensu lato). Iconographia Diatomologica 6: 276-289.
Lange-Bertalot, H. and Krammer, K. (1989). Achnanthes eine Monographie der Gattung mit Definition der Gattung Cocconeis and Nachtragen zu den Naviculaceae. Bibliotheca Diatomologica 18, 393 pp. Cramer, Berlin, Stuttgart.
Patrick, R.M. and Reimer, C.W. (1966). The Diatoms of the United States exclusive of Alaska and Hawaii, V. 1. Monographs of the Academy of Natural Sciences of Philadelphia 13.
Wustman, B.A., Gretz, M.R. and Hoagland, K.D. (1997). Extracellular matrix assembly in diatoms (Bacillariophyceae). I. A model of adhesives based on chemical characterization and localization of polysaccharides from the marine diatom Achnanthes longipes and other diatoms. Plant Physiology 113:1059.