Lamina is an expanded part of a leaf that contains chloroplasts. Its structure which catches hold of the base from the stem is kind of a thin plate or a layer that is generally broad and flat. It's vital as photosynthesis depends on it and also helps chloroplast cells to penetrate and absorb light from the atmosphere. The leaf blade is the structural part of the plant, whereas the lamina of the leaf is the flat region that contains the chloroplast, veins, and stomata.