Staurophora Guide
Credit: Loren Bahls
  1. Fascia with short striae at margins
  2. Deep, highly arched valves
  3. Striae composed of small round poroids
  4. Single lobed chloroplast with large pyrenoid

Valves of Staurophora are solitary and lanceolate, linear-lanceolate, or elliptic-lanceolate, often with protracted ends. Valve faces are strongly curved onto the mantle, which is relatively deep. As a result, cleaned frustules often come to rest in girdle view. A fascia is present and is interrupted at the margins by several short striae. These short striae may not be visible in valve view. Striae are composed of small round poroids, occluded internally by hymenes. External proximal raphe ends lie in spathulate grooves; the raphe ends are deflected slightly to one side. Terminal raphe fissures are hooked toward the secondary side of the valve. A single lobed chloroplast contains one or two prominent pyrenoids.

Staurophora is epipelic in marine and brackish waters. The preference for waters with elevated electrolytes distinguishes Staurophora from Stauroneis, which is a strictly freshwater genus. Staurophora is further distinguished from Stauroneis by having only one chloroplast, not two as in Stauroneis. Staurophora has been collected from streams on the northwestern Great Plains.