Question RE pinecones

Ross Koning koning at ECSUC.CTSTATEU.EDU
Wed Aug 6 11:46:29 EST 1997


At 11:35 AM -0400 8/6/97, dwhite1 wrote:
>Thanks for the response.  Maybe I can provide a little more detail.  The
>pine cones are about an inch long and are greyish brown.  Most of the ones
>I picked off the ground were still closed.  They did open up after a day or
>so of leaving them in my car.  However, there were no seeds to be found in
>the cones or in the car.  Am I correct in saying that the seeds should be
>at the bottom of each "petal" of the cone that opens up?  Is it possible
>that the seeds are very very small like grains of salt? or is this somehow
>a sterile tree?
>
>BTW, the tree is growing in New Jersey.
>

This is hard to answer.  The cone scales do move
with changes in humidity so a "closed" cone could
have already shed but be "closed" because of high
humidity.  Upon heating in a car they might reopen
because of the lower humidity.  Such a cone might
be empty of viable seeds.

You ARE correct that any seeds should be on the
upper surface of each cone scale.  Typically there
are two seeds on each scale.  The seeds generally
have a papery wing-like integument and a small
ovoid seed very near the point of attachment for
the cone scale.

Not every ovule gets pollinated in rainy springs,
and typically not every ovule matures in a cone.
In my experience the scales at the tip of the cone
produce few or no viable seeds, and those at the
base of the cone produce few if any.  The scales
in the middle of the cone are the most productive
based on my own observations.

Some pines have very large seeds and others have
very small ones.  Not knowing the species of plant
you are dealing with, it is hard to know where on
that continuum the plant belongs.  Yours could have
VERY small seeds.

It is also possible, however, that it was never
pollinated.  Sometimes plants require a second tree
of the same species around to achieve successful
pollination.  The male tree has to be upwind of
the female as pollen in pines is wind-carried.
So if the plant is fertile, it just might not be
being pollinated.

The tree could be some very odd conifer; the result
of genetic manipulation that is genetically sterile.
Such trees have to be vegetatively propagated (by
cuttings).  Some conifers are easy to propagate but
some are very difficult.

Since you are in NJ, you might ask some of the people
in Cook College (Rutgers University) or Princeton
(nice forestry farms!) for some on-site assistance.
Cooperative Extension staff (RU) are usually quite
nice about answering questions and helping out.

Good Luck!

ross

_______________________________________________________________
Ross Koning                 | koning at ecsu.ctstateu.edu
Biology Department          | http://koning.ecsu.ctstateu.edu/
Eastern CT State University | phone: 860-465-5327
Willimantic, CT 06226 USA   | fax: 860-465-4479
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