How does phloem distribute food through lower vascular plants?

In lower vascular plants—such as ferns, club mosses, and horsetails—the phloem is responsible for distributing organic foods, primarily sugars, from the leaves to other parts of the plant.12

Unlike the more complex sieve-tube members found in flowering plants, the phloem of lower vascular plants is composed mainly of [sieve cells]. These are narrow, elongated units that remain alive at functional maturity, possessing persistent protoplasts and nuclei. These cells feature sievelike areas on their walls, through which organic nutrients are presumed to pass as they travel through the stem and other plant organs.3

While the specific mechanisms of transport in these plants are less specialized than those in angiosperms, the phloem functions as part of the vascular system to ensure that products of photosynthesis reach areas of growth and storage. These tissues are typically organized into strands alongside xylem, surrounded by parenchyma and an outer layer known as the endodermis.143