Select the incorrect statement.

$A$ : The oldest layer of sapwood lies just outside the vascular cambium.
$R$ : Sapwood contains actively conducting vessels and occupies the central part of the stem.

Which of the following represents the correct sequence of layers from the center towards the periphery in a dicot stem?

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$:
Assertion $A$: Late wood has fewer xylary elements with narrow vessels.
Reason $R$: Cambium is less active in winters.
In the light of the above statements,choose the correct answer from the options given below:

In which stem is the lateral meristem absent?

Heartwood or duramen is: