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Compare Planothidium sheathii

Stancheva 2019

Compare

Several other species of Planothidium have a wide cavum covered by a broad hood that flares at the valve margin. In particular, P. sheathii can confused with larger specimens of P. frequentissimum. Planothidium frequentissimum has a cavum with a narrow closed hood, which is not flared and a higher stria density. Planothidium biporomum has lanceolate valves, with capitate apices and a higher stria density. Planothidium incuriatum has lanceolate valves, with subrostrate apices and a higher stria density. Planothidium cavilanceolatum has proportionally longer valves (larger length to width ratio), with slightly protracted, broadly rounded apices. Planothidium joursacense and P. abbreviatum have rapheless valves with a wider axial area and differing stria densities. Planothidium hinzianum has smaller, elliptic-lanceolate valves, acutely rounded ends, and a higher stria density.

LM scalebar = 10 µm
Planothidium Sheathii Lm09 Planothidium Sheathii Lm10 Planothidium Sheathii Lm08 Planothidium Sheathii Lm01 Planothidium Sheathii Lm03 Planothidium Sheathii Lm06 Planothidium Sheathii Lm05
Length Range
14-29 µm
Width Range
6.3-8.8 µm
Striae in 10 µm
11-13

Planothidium frequentissimum

(Lange-Bert. in Krammer and Lange-Bert.) Lange-Bert. 1999

Gs119780 1 Ed Planothidium frequentissimum LM3 Planothidium frequentissimum LM2 Mo000019 1A Ed 5 Planothidium frequentissimum LM1 Gs181995 1B Ed Mo000019 Plfreq 1B Ed
Length Range
5-17 µm
Width Range
3-6 µm
Striae in 10 µm
13-18

Planothidium biporomum

(M.H.Hohn and Hellerman) Lange-Bert. 1999

Planothidium bipororum LM3 Planothidium bipororum LM1 Planothidium bipororum LM4
Length Range
12-25 µm
Width Range
5.4-7.0 µm
Striae in 10 µm
12-15

Planothidium incuriatum

Wetzel, Van de Vijver and Ector 2013

Planothidium Incuriatum LM4 Planothidium Incuriatum LM2 Planothidium Incuriatum LM3 Planothidium incuriatum LM1 Planothidium incuriatum LM2
Length Range
19-24 µm
Width Range
6.2-7.3 µm
Striae in 10 µm
13-15

Planothidium joursacense

(Hérib.) Lange-Bert. 1999

Gc8526 Acomissa Circle4 Cl Gc8526 Acomissa Circle1B Cl Planothidium joursacense LM4 Planothidium joursacense LM2 Planothidium joursacense LM1 Planothidium joursacense LM5 Planothidium joursacense LM3
Length Range
9.6-15.6 µm
Width Range
5.5-7.3 µm
Striae in 10 µm
17-19

Planothidium abbreviatum

(Reimer) Potapova 2012

Planothidium abbreviatum LM1 Gs024101 1 Gs024101 3 Gc49756A 1B Gc49756A 1A 1 Gc43857 Aclin Abbrev Cricle1A Gc43857 Aclin Abbrev Cricle1B
Length Range
11-18 µm
Width Range
6.1-8.5 µm
Striae in 10 µm
11-12

Also compare to

Planothidium cavilanceolatum

Wetzel et al. 2019 Pg 62, Fig 464-521

Planothidium hinzianum

Wetzel et al. 2019 Pg 61, Fig 415-439, 457-463