Which scientists conducted in-depth research in the field of plant classification?

What is the minimum haploid number $(n)$ of chromosomes found in the plant kingdom?

Arrange the following examples from their simple to complex form in ascending order.
$(1)$ Equisetum $(2)$ Chlamydomonas $(3)$ Sphagnum

Cycas and Adiantum resemble each other in having

Compared with the gametophytes of the bryophytes,the gametophytes of vascular plants are:

Match Column-$I$ with Column-$II$ and select the correct option.

Column-$I$	Column-$II$
$(A)$ Sequoia sempervirens	$(p)$ Smallest gymnosperm
$(B)$ Wolffia globosa	$(q)$ Tallest plant of Australia
$(C)$ Zamia pygmaea	$(r)$ Tallest inflorescence
$(D)$ Eucalyptus (Nilgiri)	$(s)$ Tallest tree in the world
$(E)$ Rafflesia arnoldii	$(t)$ Smallest angiosperm
$(F)$ Agave (Ramban)	$(u)$ Largest flower