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Darwin, Charles, 1809-1882

"Effects of Cross and Self Fertilisation in the Vegetable Kingdom"

Many of the
self-fertilised seedlings suffered greatly, and a much larger number of
them perished than of the crossed. In the autumn the surviving
self-fertilised plants were plainly less well-grown than the crossed
plants.
7. PAPAVERACEAE.--Papaver vagum.
A SUB-SPECIES OF Papaver dubium, FROM THE SOUTH OF FRANCE.
The poppy does not secrete nectar, but the flowers are highly
conspicuous and are visited by many pollen-collecting bees, flies and
beetles. The anthers shed their pollen very early, and in the case of
Papaver rhoeas, it falls on the circumference of the radiating stigmas,
so that this species must often be self-fertilised; but with Papaver
dubium the same result does not follow (according to H. Muller 'Die
Befruchtung' page 128), owing to the shortness of the stamens, unless
the flower happens to stand inclined. The present species, therefore,
does not seem so well fitted for self-fertilisation as most of the
others. Nevertheless Papaver vagum produced plenty of capsules in my
garden when insects were excluded, but only late in the season. I may
here add that Papaver somniferum produces an abundance of spontaneously
self-fertilised capsules, as Professor H. Hoffmann likewise found to be
the case. (4/2. 'Zur Speciesfrage' 1875 page 53.) Some species of
Papaver cross freely when growing in the same garden, as I have known to
be the case with Papaver bracteatum and orientale.


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