The margin of the pinnule inG. linearisbecomes determined early in ontogeny. The bulk of the lamina is derived from an intercalary meristematic band between the margin and the midvein. The sporangiferous receptacle possesses a pronounced tetrahedral apical cell and has over‐all organization comparable to the apex of an axial entity. The receptacle is traceable to the marginal series just lateral to the apical cell of the pinnule. The receptacle is described as neither marginal nor superficial in origin, but apical, and it is interpreted as a branch of the pinnule.