In roots and stems, secondary growth takes place after the formation of

Vascular cambium of stem is

Growth rings determine

Lenticels are found in

Identify the correct order of the components with reference to their arrangement from outer side to inner side in a woody dicot stem.

$I.$ Secondary cortex

$II.$ Autumn wood

$III.$ Secondary phloem

$IV.$ Phellem

Heartwood differs from sapwood in