Caption: Sphaerostephanos . A-C , S. unitus var. unitus . A , lower surface of central lobes of a middle pinna; B , detail of sporangium; C , base of frond (A-C , R.Pullen 7620, K). D-F , S. heterocarpus . D , lower surface of central lobes of a middle pinna; E , detail of D ; F , basal pinna (D-F , Hill, Jan. 1866, K).Illustrators: P.J.Edwards.
Flora of Australia Volume 48 (1998) figure 120.