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Planothidium holstii

(Cleve) Lange-Bert. 1999      Category: Monoraphid
BASIONYM: Achnanthes holstii Cleve 1881

Planothidium haynaldii


Planothidium lanceolatum

LM scalebar = 10 µm = 40 pixels.


Contributor: Megan Otu | Sarah Spaulding - March 2011
Length Range: 18-28 µm
Width Range: 8-10 µm
Striae in 10 µm: 12-16


Valves elliptically lanceolate with slightly rostrate apices. The raphe valve has an off-set “bow tie” shaped to oval central area. The rapheless valve has a large, broad central area, becoming more narrow toward the apices. The raphe is straight with expanded, unilaterally deflected proximal ends. The distal raphe ends are deflected to opposite sides of the valve. The striae are radiate on the raphe valve and slightly radiate on rapheless valve. The striae are multiseriate.

Original Description

Basionym: Achnanthes holstii
Author: Cleve 1881
Length Range: 28 µm
Width Range: 9 µm
Striae in 10 µm: 14

Original Description

Lanceolata, apicibus attenuatis et obtusiusculis. Valva superior striis marginalibus, 14 in 0,01 m.m., nodulo centrali indistincta, linea media indistincta. Valva inferior, linea media distincta, striis radiantibus lin. med attingentibus, circa nodulum centralum abbreviatis. Long. 0,028 m.m. Lat. 0,009 m.m. Loc. Grönland, Kornak. Tab. XVI fig. 6 (valv. sup.), 7 (valv. inf.).

Original Images

Cite This Page:
Otu, M., and Spaulding, S. (2011). Planothidium holstii. In Diatoms of the United States. Retrieved May 22, 2018, from

Species: Planothidium holstii

Contributor: Megan Otu | Sarah Spaulding

Reviewer: Rex Lowe


Cleve, P.T. (1881). Färskvattens-Diatomacéer från Grönland och Argentinska Republiken. Öfversigt af Kongliga Svenska Vetenskaps-Akademiens Förhandlingar, Stockholm 38(10): 3-13.

Cleve, P.T. (1895). Synopsis of the Naviculoid Diatoms, Part II. Kongliga Svenska-Vetenskaps Akademiens Handlingar 27(3):1-219.

Cremer, H. and Wagner, B. (2003). The diatom flora in the ultra-oligotrophic Lake El’gygytgyn, Chukotka. Polar Biology 26 (2): 105-114. 10.1007/s00300-002-0445-0

Lange-Bertalot, H. (1999). Neue Kombinationen von taxa aus Achnanthes Bory (sensu lato). Iconographia Diatomologica 6: 276-289.

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Planothidium holstii CAS

North American Diatom Ecological Database (NADED)

NADED ID: 155042

Autecology Discussion