Fig. 8.1-8. Transverse section of root of corn (Zea mays). The phloem in this monocot root is much more difficult to identify than that in cat claw (Fig. 8.1-7). The arrows point out a companion cell and two sieve tube members. There are several other cells that have the proper size and shape, but which have cell contents: those are probably sieve tube members that are still differentiating and have not yet reached the stage of losing their nuclei and vacuole membrane. Note the location of the phloem: just to the side of a mass of xylem and just interior to the endodermis. One of the objectives of this micrograph is to let you know that if you sometimes have trouble identifying phloem -- don't feel bad, it can be a problem for all of us.