Dicot roots at the end of primary growth

Diagram of two preceding illustrations

A cross-sectional diagram of a dicot root at the close of primary growth showing vascular cambium initiation (shown in light green). In this diagram the xylem is tetrarch (although the complete circumference is not shown). Compare with the two preceding illustrations.

1 = rhizodermis, 2 = root hair, 3 = cortex, 4 = intercellular spaces, 5 = pericycle (one layer colored dark green), 6 = endodermis, 7 = primary phloem, 8 = protoxylem, 9 = metaxylem, 10 = initial vascular cambium, 11 = sieve plate

Illustration modified from: Weier, Stocking & Barbour, 1974, Botany: An Introduction to Plant Biology, 5th Ed. This material is used by permission of a subsidiary of John Wiley & Sons, Inc.