This passes gradually into the thinner-walled parenchyma of the inner cortex.
Distinctive yellow spots can be seen as a result of dead palisade parenchyma cells.
The sieve-tubes differ, however, from the tracheids in being immediately associated, apparently constantly, not with starchy parenchyma, but with parenchymatous cells, containing particularly abundant proteid contents, which seem to have a function intimately connected with the conducting function of the sieve-tubes, and which we may call proteid-cells.
Associated with it are other tissues, consisting of parenchyma, mainly starchy, and in the Phanerogams particularly, of special stereom.
The sieve-tubes, with their accompanying parenchyma or stereom, constitute the tissue called phloem.