I'm not sure how the endosperm ends up evenly distributed. And yes, the
multi-nucleate endosperm is unusual. I've never had the opportunity to
cut through a fully mature coconut, so I don't know if it all solidifies
or if there is a little slosh left over. I would guess that the hollow
space is indeed helpful in helping the seed float, since that's how the
plants are dispersed.
A coconut is actually a type of drupe--the husk is the exocarp and
mesocarp, and the hard brown shell is the endocarp. (Remember that what
you see in the supermarket is not the whole fruit.) There's got to be a
little embryo in there somewhere, but in all my supermarket-coconut
opening days, I have never found one. I will look a little harder in
this year's Plants and People course. The embryo might be really,
really tiny in an unripe nut.
M. Reed
David Starrett wrote:
>> At 09:24 AM 8/10/99 -0500, you wrote:
> >The coconuts sold in stores usually aren't mature. The sloshing you
> >hear, the milk, is liquid endosperm. It's an unusual phenomenon--the
> >endosperm is multi-nuclear but has no cell walls. As the fruit matures,
> >the endosperm solidifies into the "meat" of the coconut. The more milk,
> >the less ripe the nut.
>> Does a mature seed therefore have no milk? I have heard that the endosperm
> solidifies and always wondered why/how a liquid which would settle to the
> bottom coats the inside so uniformly. So, all the meat in a coconut is
> solid endosperm? Why the big hollow space? To make it float? Where is
> the cotyledon? Is there a scutellum-like structure on the embryo? What
> fruit type would a coconut fall under? (not being a true nut).
>> Guess I was luckier than I relalized getting a supermarket coconut to
> germinate.
>> Dave Starrett
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