Edlund, Laub, Siver, Hamilton and Morales 2011 Category: Araphid
BASIONYM: Fragilariforma marylandica Edlund, Laub, Siver, Hamilton, and Morales 2011
REPORTED AS: Fragilariforma strangulata (ANSP Image Database (IM000867)) | Fragilaria virescens var. torus (Desianti et al. 2015, pg. 108, Fig. 127)
Contributor: Ian Bishop - April 2016
Length Range: 16-26 µm
Width Range: 4.7-6.1 µm
Striae in 10 µm: 16-21
Valves are linear, becoming lanceolate at in smaller specimens. Apices are protracted and strongly capitate. A single rimportula is present at one apex. Striae are unevenly spaced, alternate, parallel throughout most of the valve and become curved at the apices. The sternum is very narrow and occasionally not present. No spines are visible in LM. Areolae are dense and also not visible in LM.
This taxon has been misidentified in surveys as Fragilariforma strangulata, a species described from the Belgian Congo.
Note that Fragilaria virescens var. torus Hohn and Hellerman 1966 is a heterotypic synonym of Fragilariforma marylandica (Desianti et al. 2015). Note that while F. marylandica was published later than Fragilaria virescens var. torus, it was published at the rank of species (rather than variety).
Basionym: Fragilariforma marylandica
Author: Edlund, Laub, Siver, Hamilton, and Morales 2011
Length Range: µm
Striae in 10 µm:
Desianti, N., Potapova, M. and Beals, J. (2015). Examination of the type materials of diatoms described by Hohn and Hellerman from the Atlantic Coast of the USA. Diatom Research. 10.1080/0269249X.2014.1000020
Hohn, M.H. and Hellerman, J. (1966). New diatoms from the Lewes-Rehoboth Canal, Delaware and Chesapeake Bay area of Baltimore, Maryland. Transactions of the American Microscopical Society 85: 115-130.
Hohn, M.H. & Hellerman, J. (1966). New diatoms from the Lewes-Rehoboth Canal, Delaware and Chesapeake Bay area of Baltimore, Maryland. Transactions of the American Microscopical Society 85: 115-130.
Østrup, E. (1910). Danske Diatoméer. C.A. Reitzels Boghandel, Kjøbenhavn. 323 pp., 5 pls.
Siver, P.A. and Hamilton, P.B. (2011). Diatoms of North America: The Freshwater Flora of Waterbodies on the Atlantic Coastal Plain. Iconographia Diatomologica 22.
Zanon, D.V. (1938). Diatomee della Regione del Kivu (Congo Belga). Commentationes Pontificiae academiae scientiarum 2: 535-668.
This taxon was found in two small, humic acid lakes in the Pinelands of New Jersey and in a tributary of the Severn River in Maryland (Siver and Hamilton 2011). The type population was collected from epipsammic and epilithic habitats. The imaged populations on this page were collected in the northeast, in the East Branch of the Neversink River, New York and Bearcamp River, New Hampshire.