Talk about primary meristems.

AKA apical meristems, found at or near the growing tips of plant organs, such as roots or shoots, insure growth in length (primary growth) small isodiametric and contiguous (without intercellular space) cells. Stained section shows thin primary cellulosic wall a large nucleus cytoplasm containing small spherical or arranged in a fine network vacuoles and many mitochondria and proplatids (no differentiated ones) Tissues produced are called primary tissues.