Out of the $105$ elements discovered so far,how many have been found in plants?

What does plant ash represent?

If a dried leaf is taken in a crucible and heated to $600^{\circ}C$,a gray-coloured powder is left behind. It is referred to as:

The plant ash indicates:

Woodward $(1669)$ observed that plants grew better in muddy water than in rain water because:

Water-logged condition will quickly occur in which type of soil?