Between the xylem and phloem is a meristem called the vascular cambium. The parent cells of the vascular cambium produce both xylem and phloem. Secondary xylem is formed during secondary growth from vascular cambium. The vascular cambium produces new layers of secondary xylem annually. Bark bread is a traditional food made with cambium (phloem) flour. Secondary growth occurs at the lateral meristems, namely the vascular cambium and cork cambium. The trunk consists of five main parts&colon; the bark, inner bark, cambium, sapwood, and heartwood. These are produced in the apical meristem and transported towards the roots in the cambium. Rays are horizontal rows of long-living parenchyma cells that arise out of the vascular cambium. Coniferin, CHO, occurs in the cambium of conifer wood. Synonyms for cork cambium are bark cambium, pericambium and phellogen. Bark refers to all the tissues outside the vascular cambium and is a nontechnical term. Cork is generated by a specialized layer of tissue called "cork cambium". Before the cortex is destroyed, a cork cambium develops there. Cambium and other actively dividing tissues also synthesize cytokinins.