Fig. 14. Hypothetical ontogeny of adaxial and abaxial carpogonial branches (c.bs) in the Ceramiales.
A. The ancestral type where c.bs developed on cells of main and lateral filaments of unlimited growth (Athanasiadis 1996, p. 36).
B. The ancestral type of Balliella, where c.bs developed on axial cells and were transferred to periaxial cells either adaxially or abaxially (only abaxial c.bs have persisted in Balliella).
C. The ancestral type of the Callithamnioideae, where c.bs developed directly on periaxial cells either abaxially or adaxially (only abaxial c.bs have persisted in the Callithamnioideae).
D. The ancestral type of the Ceramioideae that gave rise to abaxial c.bs (as generally occurs in the subfamily) and adaxial c.bs (as occurs in Inkyuleea). Frames indicate hypothetical types. Shaded filaments are of unlimited growth and unshaded filaments are of limited growth.