17. lf. Ferns or leafless plants with three angled stems A. Plants bearing scalelike "leaves" or appendages but appearing leafless from a short distance................Psilotaceae Psilotum nudum (L) Griseb. AA. Plants bearing fronds....................Polypodiaceae B. Fruiting bodies borne in clusters (sori) arranged in dots, lines, or larger areas on the lower surface of the frond; plant growing on the ground or some on supports; fertile and sterile fronds similar C. Tip of frond coiled at maturity.....Nephrolepis CC. Tip of frond not coiled at maturity