Psammothidium daonense

(Lange-Bertalot) Lange-Bertalot 1999      Category: Monoraphid
BASIONYM: Achnanthes daonensis Lange-Bertalot 1989
SYNONYM(S): Psammothidium grischunum f. daonensis (Lange-Bertalot) Bukhtiyarova and Round 

Psammothidium curtissimum


Psammothidium didymum

LM scalebar = 10 µm = 80 pixels.


Contributor: Marina Potapova - August 2010
Length Range: 9-23 µm
Width Range: 4.8-7.5 µm
Striae in 10 µm: 24-30


Valves are elliptical to linear-elliptical. The raphe valve has a linear axial area, which widens into a transapically elliptical, rectangular, or diamond-shaped central area. The raphe is straight, without terminal fissures. The central and terminal raphe ends are slightly expanded externally. The central raphe ends curve toward opposite sides internally. The rapheless valve has a large rhomboid axial area, which has an irregular border. The central area is usually not differentiated from the axial area. Striae are radiate on both valves, 24-30 in 10 µm, interrupted at the valve margin. One row of areolae is present on the mantle of both valves; occasionally a second row of areolae is inserted on the valve margin. Areolae are 36-48 in 10 µm within the striae. The external openings of the areolae are mostly circular, occasionally elongated.

Original Description

Basionym: Achnanthes daonensis
Author: Lange-Bertalot 1989
Length Range: 10-26 µm
Width Range: 5-8 µm
Striae in 10 µm: 27-32

Original Description

Valvae ellipticae ad lineari-ellipticae apicibus late rotundatis non protractis, 10-26 μm longae, 5-8 μm latae. Raphovalva: Raphe filiformis recta, poros terminales influens; pori centrales modice approximate. Area axialis anguste linearis area centralis variabiliter transverse dilatata. Areovalva: Area axialis plus minusque late lanceolata influens in aream centralis rhombicam irregulariter marginatum. Striae transapicales modice radiantes in media parte valvarum usque ad apices, 27-32/10 μm. Quamquam similis a A. marginulata, A. kryophila, A. helvetica satis differt.

Original Images

Cite This Page:
Potapova, M. (2010). Psammothidium daonense. In Diatoms of the United States. Retrieved September 25, 2016, from

Species: Psammothidium daonense

Contributor: Marina Potapova

Reviewer: Sarah Spaulding


Bukhtiyarova, L. and Round, F. E. (1996). Revision of the genus Achnanthes sensu lato. Psammothidium, a new genus based on Achnanthidium marginulatum. Diatom Research 11: 1-30.

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.

Manoylov, K.M. (2007). On some Psammothidium species from rivers in the United States. Diatom Research 22(2): 317–327.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Psammothidium daonense CAS

North American Diatom Ecological Database (NADED)


Autecology Discussion