Unusual cotyledon behaviour
 

Maybe a little OT, but has anyone seen seedling behaviour like this:
http://tinypic.com/r/wt8w7a/9

These are seedlings of Plum Mango (Bouea macrophylla), grown from seeds
obtained from fruit bought at that well-known purveyor of exotic seeds,
Marks & Spencer. What is strange to me is that the leaves hang down
vertically. I have never seen this before with any seedling.

The youngest one, extreme right, germinated a week ago, and when it
first appeared I am pretty sure the leaves were almost horizontal, but
within a few hours had dropped to the position shown. The oldest
seedling (about a month old) now has green, rather than brownish leaves,
but these still show no sign of moving to a horizontal position. I would
have though that a horizontal leaf position would be sought by all
seedlings as that is the most efficient fr photosynthesis.

--

Jeff

Unusual cotyledon behaviour
 

On 27/05/2016 08:55, Jeff Layman wrote:
Maybe a little OT, but has anyone seen seedling behaviour like this:
http://tinypic.com/r/wt8w7a/9

These are seedlings of Plum Mango (Bouea macrophylla), grown from seeds
obtained from fruit bought at that well-known purveyor of exotic seeds,
Marks & Spencer. What is strange to me is that the leaves hang down
vertically. I have never seen this before with any seedling.

The youngest one, extreme right, germinated a week ago, and when it
first appeared I am pretty sure the leaves were almost horizontal, but
within a few hours had dropped to the position shown. The oldest
seedling (about a month old) now has green, rather than brownish leaves,
but these still show no sign of moving to a horizontal position. I would
have though that a horizontal leaf position would be sought by all
seedlings as that is the most efficient fr photosynthesis.

would it be an adaption to heavy rain fall? Also I seem to remember that
the leaves on the adult trees hang down, but I could be wrong as its a
while since I saw one!

--
Charlie Pridham, Gardening in Cornwall
www.roselandhouse.co.uk
National collections of Clematis viticella & Lapageria rosea

Unusual cotyledon behaviour
 

In article ,
Charlie Pridham wrote:
On 27/05/2016 08:55, Jeff Layman wrote:
Maybe a little OT, but has anyone seen seedling behaviour like this:
http://tinypic.com/r/wt8w7a/9

These are seedlings of Plum Mango (Bouea macrophylla), grown from seeds
obtained from fruit bought at that well-known purveyor of exotic seeds,
Marks & Spencer. What is strange to me is that the leaves hang down
vertically. I have never seen this before with any seedling.

The youngest one, extreme right, germinated a week ago, and when it
first appeared I am pretty sure the leaves were almost horizontal, but
within a few hours had dropped to the position shown. The oldest
seedling (about a month old) now has green, rather than brownish leaves,
but these still show no sign of moving to a horizontal position. I would
have though that a horizontal leaf position would be sought by all
seedlings as that is the most efficient fr photosynthesis.

would it be an adaption to heavy rain fall? Also I seem to remember that
the leaves on the adult trees hang down, but I could be wrong as its a
while since I saw one!

Also remember that, in the tropics, sunlight is not in short supply
and the noonday sun is fierce. That might be a protection against
burning, while catching the morning and evening sun. But I agree
that it's odd, and that Charlie has the most likely explanation.


Regards,
Nick Maclaren.

Unusual cotyledon behaviour
 

On Fri, 27 May 2016 08:55:02 +0100, Jeff Layman wrote:

Maybe a little OT, but has anyone seen seedling behaviour like this:
http://tinypic.com/r/wt8w7a/9

These are seedlings of Plum Mango (Bouea macrophylla), grown from seeds
obtained from fruit bought at that well-known purveyor of exotic seeds,
Marks & Spencer. What is strange to me is that the leaves hang down
vertically. I have never seen this before with any seedling.

The youngest one, extreme right, germinated a week ago, and when it
first appeared I am pretty sure the leaves were almost horizontal, but
within a few hours had dropped to the position shown. The oldest
seedling (about a month old) now has green, rather than brownish leaves,
but these still show no sign of moving to a horizontal position. I would
have though that a horizontal leaf position would be sought by all
seedlings as that is the most efficient fr photosynthesis.

If you are in an open area you can stretch your arms out.

If you are on the tube in rush hour then you hunch everything in.

Looks like a way to get the maximum leaf area in the minimum space - grow
up tall and thin with nothing sticking out too far to catch on other
plants/trees.

Cheers


Dave R


--
Windows 8.1 on PCSpecialist box

Unusual cotyledon behaviour
 

On 27/05/16 08:55, Jeff Layman wrote:
Maybe a little OT, but has anyone seen seedling behaviour like this:
http://tinypic.com/r/wt8w7a/9

These are seedlings of Plum Mango (Bouea macrophylla), grown from seeds
obtained from fruit bought at that well-known purveyor of exotic seeds,
Marks & Spencer. What is strange to me is that the leaves hang down
vertically. I have never seen this before with any seedling.

The youngest one, extreme right, germinated a week ago, and when it
first appeared I am pretty sure the leaves were almost horizontal, but
within a few hours had dropped to the position shown. The oldest
seedling (about a month old) now has green, rather than brownish leaves,
but these still show no sign of moving to a horizontal position. I would
have though that a horizontal leaf position would be sought by all
seedlings as that is the most efficient fr photosynthesis.

Thanks for the replies and suggestions for the behaviour. It may well be
an adaptation to heavy rain (the leaves are very thin), but as to
whether or not the adult plants have the same pattern depends on what
photo you look at!

The Wikipedia photo definitely appears to show pendant leaves
(https://upload.wikimedia.org/wikiped...-0024_ipb.jpg).


The Fruitpedia photo is a bit mixed
(http://www.fruitipedia.com/gandaria%...crophylla.htm).

The photos at Toptropicals show them all over the place
(http://toptropicals.com/catalog/uid/...burmanica.htm).

I just checked another tropical plant I'm wasting time on growing from
seed - Sour Santol (Sandoricum koetjape). That is more advanced, and
although I'm pretty sure the cotyledons were more horizontal than
vertical, the true leaves are fairly pendant.

It will be interesting to see how these species grow over the next year
or so until they get too big for the conservatory, or I get fed up with
them!

--

Jeff

Unusual cotyledon behaviour
 

On 27/05/2016 08:55, Jeff Layman wrote:
Maybe a little OT, but has anyone seen seedling behaviour like this:
http://tinypic.com/r/wt8w7a/9

These are seedlings of Plum Mango (Bouea macrophylla), grown from seeds
obtained from fruit bought at that well-known purveyor of exotic seeds,
Marks & Spencer. What is strange to me is that the leaves hang down
vertically. I have never seen this before with any seedling.

The youngest one, extreme right, germinated a week ago, and when it
first appeared I am pretty sure the leaves were almost horizontal, but
within a few hours had dropped to the position shown. The oldest
seedling (about a month old) now has green, rather than brownish leaves,
but these still show no sign of moving to a horizontal position. I would
have though that a horizontal leaf position would be sought by all
seedlings as that is the most efficient fr photosynthesis.



It could be any of the other suggestions, but is it also possible that
this is a way for the young plant to direct rainwater to its root zone,
so that it thrives. The canopy of many plants becomes their own
'umbrella' and deflects rainwater so that it waters the outer root zone,
which is fine in natural habitat where roots can spread, but creates a
problem when we confine that plant to a pot. A young plant, and
especially a seedling, needs water at its new, developing root system.

--
Spider
On high ground in SE London
Gardening on heavy clay