which phylum of land plants produces the tallest individual organisms?

Answer 1

The tallest trees on earth are of the Division Pinophyta, Class Pinopsida and Order Pinales. These are the:

Sequoia sempervirens or "Coast Redwood"

and the

Pseudotsuga menziesii or "Coast Douglas-fir"

The tallest members of both species being in excess of 300ft high!