Sherwood and Lowe 2009 Category: Monoraphid
BASIONYM: Achnanthes longboardia Sherwood & Lowe 2009
Contributor: Rex Lowe - December 2011
Length Range: 23-48 µm
Width Range: 8-10.5 µm
Striae in 10 µm: 13-15 on raphe valve, 12-14 on rapheless valve
Valves are lanceolate with slightly swollen center and rounded ends. The raphe valve has a narrow axial area with the central area expanded laterally to the valve margins. The proximal raphe ends are deflected slightly in the same direction while the distal raphe ends curve strongly toward the mantle in a direction opposite the proximal raphe ends. The axial area on the rapheless valve is near the valve margin and central area is lacking. On the raphe valve striae are punctate and parallel in the center becoming radiate near the ends. Striae on the rapheless valve are strongly curved near the apicies.
Basionym: Achnanthes longboardia
Author: Sherwood & Lowe 2009
Length Range: 19-51 µm
Width Range: 8-11 µm
Striae in 10 µm:
Valves lanceolate with rounded ends, slightly swollen near the center in larger valves 19-50.5 long 8-10.5 wide. Raphe valve with narrow axial area with a wide central area expanded laterally to the valve margins. Raphe with proximal ends deflected slightly in the same direction with distal raphe ends curved strongly toward mantle in opposite direction. Rapheless valve with axial area near the valve margin. Striae punctate and parallel in the center becoming radiate near the ends. Striae on the rapheless valve are strongly curved near the apicies.
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.
Achnanthes longboardia was described from a wet wall in Oahu, Hawaii.