The balloon-like outgrowth of parenchyma in the lumen of a vessel is known as:

The wood is,in fact,a

$A$ nail is driven into the trunk of a $30$ year old tree at a point $1$ meter above the soil level. The tree grows in height at the rate of $0.5$ meters a year. After three years,the nail will be

Define the following terms:
$(i)$ Early wood
$(ii)$ Late wood

Secondary growth is absent in

How does sapwood transform into heartwood?