what are the general characteristics of pteridophytes?
['Pteridophytes are the first true land plants: ... ', 'They are seedless, vascular cryptogams: ... ', 'They show true alternation of generations: ... ', 'Sporophyte has true roots, stem and leaves: ... ', 'Spores developed in sporangia are homosporous or heterosporous: ... ', 'Sporangia are produced in groups on sporophylls:']