Guide to Sellaphora
Credit: Megan Otu, Sarah Spaulding
- Valve linear, lanceolate or elliptic
- Polar bars at apices, in some taxa
- Striae uniseriate or biseriate
- Conopeum present, in some taxa
Valves are linear, lanceolate, or elliptic with bluntly rounded poles. Polar bars, also termed "transapical thickenings", are present in some taxa. The axial area is distinct, and may be expanded along the apical axis to form a conopeum. The external proximal raphe ends are dilated. The terminal raphe fissurs are deflected.
Sellaphora is widespread in alkaline to brackish waters of neutral pH. It contains the former Navicula pupula Kützing group. The genus also includes a number of small species that have been variously included in Navicula, Eolimna and Craticula. The publication by Wetzel et al. (2015) is an important revision of several small species now within the genus.