In article ,
Iris Cohen wrote:
You must have missed my reply. The first leaves on a flowering plant are not
true leaves, and they are not evolutionary vestiges of anything. They are
called cotyledons, or seed leaves. They are the endosperm that was inside the
seed. They contain starch and/or sugar, and are there to feed the baby plant
until it has enough roots & leaves to feed itself. If you want an analogy from
the animal kingdom, it is the equivalent of the yolk sac on a baby fish.
Go get yourself some dried lima beans. Put them in a jar next to the glass,
backed up by some wet paper towels. Leave them in a well-lit spot for a week or
so & watch what happens.

He's probably killfiled you for lack of belief in his Atom Totality
religion.

What he should really do is plant some Scarlet Runner beans (Phaseolus
coccineus) next to some common beans (P.vulgaris). The former have
hypogeal cotyledons which don't spread out into "seed leaves". However
both have first true leaves with only one rather than three leaflets.
No doubt this would stimulate ab initio theories about how much more
advanced the former is over the latter, evolutionarily, since the
'seed leaves' are more like 'normal' leaves!

Of course, if he were actually observing rather than pontificating, he
might have noticed a few things about onion and corn seedlings, and if
he would exert himself to open a biology textbook he might learn a bit
about why his pine seedlings look different from his angiosperm
seedlings.