Eurygonum pennaforme Wisshak, Gektidis, Freiwald et Lundälv, 2005

Type microboring; substrate calcareous; tracemaker plant.

Diagnosis: Colonies oriented closely parallel to the substrate surface, consisting of radiating main galleries from which second- and third-order galleries of uniform diameter bifurcate uni- or bilaterally in angles between 45 and 80◦ and may exhibit distinct, club-shaped terminal swellings.

Description: Colonies are oriented close to the substrate surface and exhibit a feather-like overall branching pattern with radiating main galleries from which second- and thirdorder galleries of equal uniform diameter (ca. 4–6 µm) and circular outline, uni- or bilaterally bifurcate in angles between 45 and 80◦. Branching points may be slightly swollen and the galleries may exhibit distinct, elongated, club-shaped, terminal swellings 6–10 µm in diameter.