Plants not reproducing by seeds.Plants reproducing by seeds.Stems prominently jointed: leaves whorled, forming a sheath at stem nodes.Stems not jointed; leaves absent or if present, not whorled and forming a sheath at the nodes.Sporangia borne on stems, in the axils of leaves or leaf-like organs, or embedded in the expanded bases of such organs.Sporangia borne otherwise (on leaves or in nut-like sporocarps).Sporangia fused to form synangia.Sporangia not fused into synangia.Ovules not enclosed in a carpel; ovules arranged in cones or solitary on a short fleshy axis (non-flowering seed plants).Ovules enclosed in a carpel; carpels arranged in flowers (flowering plants).Leaves pinnate.Leaves simple