As in other members of the family Phyllophoraceae in summer, older plants of Petroglossum nicaeense (Duby) Schotter tend to produce numerous proliferations arising from the margins of the leafy fronds. These adventitious shoots direct their apex towards the substratum, giving rise to creeping axes. We have verified this behaviour in the laboratory using different types of substratum (glass, calcite, marble, shells, agar). The first stage of growth in culture is the formation of adventitious creeping axes and their adhesion to the solid substratum. Under suitable conditions, the adhesion is enhanced by the development of haptera. The second stage is the formation of erect fronds, which flatten when facing the source of light. Hence, we suggest that for this Hemicryptophyte the proliferation of fronds represents an important mechanism of substitution and integration of the creeping thallus.