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Darwin, Charles, 1809-1882

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


Professor Asa Gray states that the plants of this species growing in the Botanic
Gardens at Cambridge, U.S., are short-styled, but that Siebold and Zuccarini
describe the long-styled form, and give figures of two forms; so that there can
be little doubt, as he remarks, about the plant being dimorphic. (3/16. 'The
American Naturalist' July 1873 page 422.) I therefore applied to Dr. Hooker, who
sent me a dried flower from Japan, another from China, and another from the
Botanic Gardens at Kew. The first proved to be long-styled, and the other two
short-styled. In the long-styled form, the pistil is in length to that of the
short-styled as 100 to 38, the lobes of the stigma being a little longer (as 10
to 9), but narrower and less divergent. This last character, however, may be
only a temporary one. There seems to be no difference in the papillose condition
of the two stigmas. In the short-styled form, the stamens are in length to those
of the long-styled as 100 to 66, but the anthers are shorter in the ratio of 87
to 100; and this is unusual, for when there is any difference in size between
the anthers of the two forms, those from the longer stamens of the short-styled
are generally the longest. The pollen-grains from the short-styled flowers are
certainly larger, but only in a slight degree, than those from the long-styled,
namely, as 100 to 94 in diameter.


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