"Dave Poole" wrote in message
...
Rupert wrote:

I withdraw my vote for Avocado. Dave has got a good handle on this one.
I don't think the stone turns green when it grows or does it?

No it doesn't. If the seed coat of avocado is removed, the large
creamy egg shape you are left with is the endosperm, which stores
starches to be converted to sugars that nourish the germinating
embryo. It does not have chloroplasts and cannot turn green.
Occasionally, superficial oxidisation of starches close to the surface
of the endosperm cause it to stain purplish.

The mystery object cannot be a seed, nut or fruit, it has to be a
tuber of some sort. I can't begin to count the number of different
species of plants I've grown from all over the world, but it must
several thousand by now. I've never seen seeds that develop roots in
this way and I am certain that there are no plants where rooting
occurs from the main body of the cotyledon or from the endosperm.

Dave Poole
Torquay, Coastal South Devon UK
Winter min -2°C. Summer max 34°C.
Growing season: March - November

Excellent -I double withdraw my vote.
You can go to bed now in the true knowledge that I am happy and I do not
concrete D Antarctica into the ground.