RECORD: Darwin, C. R. 1866. [Note on the common broom, Cytisus scoparius.] In Henslow, George, Note on the structure of Indigofera, as apparently offering facilities for the intercrossing of distinct flowers. [Read 19 April] Journal of the Linnean Society of London (Botany) 9: 355-8, p. 358.
REVISION HISTORY: Transcribed and edited by John van Wyhe 2003-8. RN2
In connexion with these observations I would wish to quote a description of the somewhat similar construction in Cytisus scoparius, kindly communicated to me by Mr. Darwin. He says,
"In the Broom, if the flowers be protected from insects, the parts (stamen and pistil) do not spring out, and scarcely any pods are produced. In a flower lately expanded, when a bee alights on the keel, the shorter stamens alone are ejected, and they dust the abdomen of the insect. When the flower is a day or two older, if a bee alights on the keel, the pistil and longer stamens spring violently out, and the hairs on the pistil deposit plenty of pollen on the bee's back, against which the stigma is rubbed. When the bee flies away, the pistil curls still more, and the stigmatic surface becomes up-turned, and stands close to the protruded anthers of the shorter stamens. We have seen that the bee gets dusted in its abdomen from the shorter stamens of the younger flowers; and this pollen will be left on the up-turned stigma of the curled pistil of the older flowers. Thus both the upper and lower surface of the bee gets dusted with pollen, which will be transferred to the stigma at two different periods."2
1 Read Apr. 19 by George Henslow in relation to his paper Note on the structure of Indigofera, as apparently offering facilities for the intercrossing of distinct flowers. [With additional notice of Dr Hildebrand's paper on Medicago, Indigofera, and Cytisus, in the Botanische Zeitung, March 1866; and a communication from Mr Darwin on the common broom (Cytisus scoparius).] Ibid., pp. 355-358. Volume dated 1867. R. B. Freeman.
2 See Correspondence vol. 14, p. 135.
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Citation: John van Wyhe, editor. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
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