Habitus of Riella macrocarpa and species traits: A. Male and female individuals in the same patches in the field; Birgi Novo, Sicily, Italy; B. habitus of female plants; Ulcinj Salina, Montenegro; C. Female plants with sporophytes; Birgi Novo, Sicily, Italy; D. Male plants with ripe and unripe antheridia; Birgi Novo, Sicily, Italy; E. A spore escaping from the female involucre. Note the opened apex of the involucre; Birgi Novo, Sicily, Italy. (Photographs: A – A. Troia; C–E – D. Salemi; B – R. Romanov).