Psammothidium Alpinum Guide
Credit: Marina Potapova
  1. Valves linear-elliptic to oval
  2. Raphe straight
  3. Areolae coarse

Valves are linear-elliptic to oval. The raphe valve has a rectangular-irregular central area. The raphe is straight with drop-shaped distal ends and the terminal fissures are absent. The rapheless valve has an irregular, rounded to rhomboid central area. Areolae are coarse, round and number 25 in 10 μm.

Diatoms of North America is running a fundraising campaign to keep the servers in operation. We need you to reach our $25,000 fundraising goal.

If you use and appreciate DONA, make your DONAtion today.

For the Gift Designation, type "diatom" in the search box and select "Diatom Lab Research Fund". This is the designated fund for diatoms.org.