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Darwin, Charles, 1809-1882

"The Different Forms of Flowers on Plants of the Same Species"

Lastly, L.
Lewisii is said by Planchon to bear on the same plant flowers with stamens and
pistils of the same height, and others with the pistils either longer or shorter
than the stamens. This case formerly appeared to me an extraordinary one; but I
am now inclined to believe that it is one merely of great variability. (3/10.
Planchon in Hooker's 'London Journal of Botany' 1848 volume 7 page 175. See on
this subject Asa Gray in 'American Journal of Science' volume 36 September 1863
page 284.)
PULMONARIA (BORAGINEAE).
Pulmonaria officinalis.
Hildebrand has published a full account of this heterostyled plant. (3/11.
'Botanische Zeitung' 1865 January 13 page 13.) The pistil of the long-styled
form is twice as long as that of the short-styled; and the stamens differ in a
corresponding, though converse, manner. There is no marked difference in the
shape or state of surface of the stigma in the two forms. The pollen-grains of
the short-styled form are to those of the long-styled as 9 to 7, or as 100 to
78, in length, and as 7 to 6 in breadth. They do not differ in the appearance of
their contents. The corolla of the one form differs in shape from that of the
other in nearly the same manner as in Primula; but besides this difference the
flowers of the short-styled are generally the larger of the two. Hildebrand
collected on the Siebengebirge, ten wild long-styled and ten short-styled
plants.


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