Achnanthes mauiensis

R.L.Lowe and A.R.Sherwood 2009      Category: Monoraphid

Achnanthes longboardia


Achnanthes rostellata

LM scalebar = 10 µm = 80 pixels.


Contributor: Rex Lowe - December 2011
Length Range: 22-27 µm
Width Range: 5-7.5 µm
Striae in 10 µm: 15-19 on both valves


Valves are linear with a gibbous center and narrow, rostrate ends. Some specimens are not symmetric to the apical axis, and have ends that are slightly bent. The raphe valve has a narrow axial area and the central area is expanded to the valve margins. The proximal raphe ends are slightly deflected in one direction. The distal ends are curved strongly towards the mantle, in the opposite direction of the proximal deflection. The axial area of the rapheless valve is positioned near the valve margin. The striae are punctate and radiate on raphe valve. The striae on the rapheless valve are parallel in the center, becoming radiate with respect to the axial area and slightly curved at the apices.

Original Description

Author: R.L.Lowe and A.R.Sherwood 2009
Length Range: 20-28 µm
Width Range: 5.0-7.5 µm
Striae in 10 µm: 15-19

Original Description

Valves linear, swollen in the center, with narrowed rostrate ends, 20-28 µm long, 5.0-7.5 µm wide. Raphe valve with narrow axial area, with central area expanded to the valve margins (Figs 9-12, 17, 18). Raphe with proximal ends deflected slightly in one direction, with distal ends curved strongly towards mantle in opposite direction (Fig. 17). Rapheless valve with axial area near valve margin (Figs 13-16, 19), Striae punctate, radiate on raphe valve, on rapheless valve parallel in the center, becoming radiate with respect to the axial area and slightly curved at the apices, 15-19 in 10 gm on both valves. Puncta 20 in 10 µm on both valves.

Original Images

Cite This Page:
Lowe, R. (2011). Achnanthes mauiensis. In Diatoms of the United States. Retrieved April 22, 2018, from

Species: Achnanthes mauiensis

Contributor: Rex Lowe

Reviewer: Sam Rushforth


Lowe, R.L., Sherwood, A.R. and Ress, J.R. (2009). Freshwater species of Achnanthes Bory from Hawai’i. Diatom Research 24(2): 327-340. 10.1080/0269249X.2009.9705805

Links & ID's

Index Nominum Algarum (INA)

Original INA

California Academy of Sciences (CAS)

Achnanthes mauiensis CAS

North American Diatom Ecological Database (NADED)


Autecology Discussion

Present only on two collections from Maui from a wet wall along the Hana Highway. It occurred in association with Diadesmis pantropica, Diadesmis sp., Achnanthes inflata, Geissleria ignota, Fallacia insociabilis and Nitzschia cf. clausii.