The cork cambium, cork and secondary cortex are collectively called:

This wood is dark in color,has high density,and contains fewer,narrower vessels.

Which of the following meristems is responsible for the formation of the extra-stelar secondary growth in a dicot stem?

Select the wrong statement regarding secondary phloem.

Identify the correct statements:
$A$. Lenticels are the lens-shaped openings permitting the exchange of gases.
$B$. Bark formed early in the season is called hard bark.
$C$. Bark is a technical term that refers to all tissues exterior to vascular cambium.
$D$. Bark refers to periderm and secondary phloem.
$E$. Phellogen is single-layered in thickness.
Choose the correct answer from the options given below:

Define the following terms:
$(i)$ Conjoint vascular bundles
$(ii)$ Secondary growth