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Guide to Geissleria ignota

(Krasske) Lange-Bert. and Metzeltin 1996

Geissleria Ignota Guide
Credit: Rex Lowe
  1. Valves triundulate
  2. Central area expanded
  3. Striae radiate near center, becoming parallel near apices
  4. Annulae consist of 2-3 pairs of striae

Valves triundulate with rostrate to subcapitate ends. The central area is expanded laterally with 2-4 shortened striae at the valve margin. Striae are radiate near the center of the valve, becoming parallel near the ends. Annulae consisting of two to three pairs of striae are present at each apex of the valve.