In monocots and dicots, the energy starts in the seed's cotyledons, which
are highly modified leaf structures consisting mostly of starch. It's
complex mechanism that triggers germination, much more than I know about,
but once germination is triggered the growth is fed from the cotyledons.

Secondary growth arises from zones of maturation, in which clusters of
'totipotent' cells called Parenchyma can become any type of cell the plants
need.

An excellent book is 'Botany for Gardeners', Capon.

Dave

"Jim Elbrecht" wrote in message
news
"keith" wrote:

-snip-
I had no idea it was that much. That's fascinating! I'm going to start
fermenting my beer next to my plants. See what a little more CO2 does.
:-)

In some plants it promotes blossoming.

Jim