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Darwin Correspondence Project

From Peter Henderson   15 November 1876

Greenhouses, Jersey City Heights, N.J., | Seed Store, No. 35 Cortlandt Street, New York,

November 15 1876

Mr Charles Darwin, Dear Sir,

I am the writer of a book for Amateurs in Gardening, a copy of which I mail you today, at page 47. you will observe I take the liberty to combat your views on the subject of “Graft Hybrids”,1 in reading your remarks on the subject however, I omitted to notice your allusion to the case of Cytisus Adami, which is claimed to be a “graft hybrid”, between C. Laburnum and purpurea. This case would seem to have been the most marked one on record in favor of the theory of “graft hybrids”,2 but unfortuneately for that beleif, but fortunately, perhaps, for truth I have found a gentleman, William J. Davidson, (who is Recording Secretary of the Horticultural Society of New York)3 who asserts most positively that thirty years ago he saw, a tree of Cytisus Laburnum, upwards of fifteen feet in height, from the topmost branches of which a branch produced purple flowers, The tree had never been budded or grafted, a most ridgid examination made certain, so that here it would appear there was no other explanation for the anomaly than what you so aptly call “bud variation”, which all large cultivators see in hundreds of different species in one form or another— Why then may not the Cytisus Adami have also been a bud variation, instead of a so-called “graft hybrid”— I may state that Mr Davidson the gentleman who is my authority for the above is an excellent Botanist as well as a Practical Horticulturist of most extensive experience, and a man of strict integrity— A Lady friend Mrs Hanaford, who is one of my neighbours, wrote to you that I was experimenting with Dionea to test the insect eating theory, I will be glad to inform you of the results when that Experiment is completed.—4

Very respectfully yours | Peter Henderson


Henderson discussed graft hybrids in his Gardening for pleasure (Henderson [1875], pp. 47–51), arguing that apparent instances of the stock influencing the scion or vice versa were in fact caused by normal variation or by the transmission of disease.
Henderson had read CD’s remarks on an example of apparent influence of the stock on the scion in Variation US ed. 1: 457 (Variation 1: 380). In Variation US ed. 1: 465–9 (Variation 1: 387–91), CD discussed the possible origins of Cytisus adami, an intermediate form between the common yellow laburnum C. laburnum (now Laburnum anagyroides) and C. purpureus, a dwarf purple broom (Bean 1970–88, 2: 510–11). Cytisus adami was noted for its red, sterile flowers, but frequently some branches would revert to either parent form, bearing yellow or purple flowers.
Davidson has not been further identified but may have been Henderson’s former business partner (see ‘Peter Henderson & Company’, Jersey City past and present, (accessed 16 April 2015).
See letter from Phebe Hanaford, 3 September 1876. No letter containing the results of Henderson’s experiments on Dionaea (Venus fly trap) has been found. However, in Henderson 1884, p. 223, he claimed that he found no difference between plants that had been fed with insects for six months and plants that had not.


Bean, William Jackson. 1970–88. Trees and shrubs hardy in the British Isles. 8th edition, fully revised by D. L. Clarke and George Taylor. 4 vols. and supplement. London: John Murray.

Henderson, Peter. [1875.] Gardening for pleasure. A guide to the amateur in the fruit, vegetable, and flower garden, with full directions for the greenhouse, conservatory, and window-garden. New York: Orange Judd Company.

Henderson, Peter. 1884. Garden and farm topics. New York: Peter Henderson & Co.

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.

Variation US ed.: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. New York: Orange Judd & Co. [1868.]


Reports graft-hybrids in Cytisus.

Letter details

Letter no.
Peter Henderson
Charles Robert Darwin
Sent from
New York
Source of text
DAR 166: 140
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 10673,” accessed on 28 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 24