seeds

James W. Perry jperry at UWC.EDU
Fri Mar 20 17:43:42 EST 1998


Kathleen, et. al,

I recommend pinyon pine seed. Very hard seed coat (integument) with a thin
remnant of megasporanium internally, then embryo-containing female
gametophyte.

jim

At 12:48 PM 3/20/98 -0800, you wrote:
>Colleagues,
>I'm teaching a course which surveys the plant kingdom, and I have taken an
>evolutionary approach.  Coming up in 2 weeks I will be introducing the
>concept of the seed, and I have been thinking about an exercise which will
>illustrate to the students all the different components of the seed:
>integument, megasporangium (nucellus), embryo, etc.  The 2 parts that I
>think might be hard to show in a real specimen are the integument and the
>nucellus (or remnant thereof) since in many seeds the nucellus is long gone
>by the time the seed is mature.  I know in some seeds the seed coat has an
>inner and outer layer which may separate but are still derived from
>integument and I don't want to be inaccurate and call the inner layer
>nucellus if in fact it is not.  I'm trying to find a seed where it is known
>that the layer within the seed coat is in fact nucellar in origin.  
>
>I wonder if anyone can recommend a seed which could be dissected to show
>clearly and distinctly both the integument and the remnant of the nucellus?
> Something large and relatively easy to come by would be great.
>Thanks for any help,
>Kathleen Archer
>
>
>



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