Plants are placed into two simple kingdom subsections: nonvascular and vascular plants. The big distinction between the two groups is that vascular plants have vascular_tissues: tissues that conduct water and dissolved food in the plant body. The vascular tissues include xylem, which moves water and minerals upward through the plant and phloem, which moves dissolved food downward in the plant.
Nonvascular plants lack these tubes, and therefore must be small and thin so that each cell can acquire its needed materials via passive_transport from the plant's surface, or from other cells within the plant that are located near the surface.
Regardless of whether a plant is vascular or nonvascular, it has structures that (1) anchor it into the soil, (2) provide physical support for its photosynthetic structures, and (3) specialize in performing photosynthesis.
The difference is that in nonvascular plants these structures are called root-like, stem-like, and leaf-like because they lack vascular tissues. True roots, stems, and leaves are those body structures that contain vascular tissues.
Lycopodium is a representative of the club_mosses. Their sporangia aggregate in cones during the sporophyte stage. Their gametophyte is reduced and grows beneath the soil. Photo Atlas micrograph 48D reveals the organization of the Lycopodium strobilus (cone). The sporophyll is asexual tissue that surrounds, physically supports and protects the sporangia. Photograph 48B is a real external view of Lycopodium and shows the strobilus that is present as a longitudinal section on your slide (and micrograph 48D).