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Darwin Correspondence Project

To Daniel Oliver   10 March 1877

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R.

Mar 10 1877

My dear Mr Oliver

I want to beg your assistance with respect to a subject to which you have attended in your interesting article in the old Nat. Hist. Review; but it will be a mere chance whether you can aid me.1

First let me thank you for the great trouble which you took, as I hear from my son Francis, in sending me specimens, most of which have proved of the greatest value to me.2

Mr Thwaites sent me from Ceylon many flowers preserved in spirits of Oxalis sensitiva, which proved to be trimorphic; & to my surprize there were on the same flower-stalks cleistogamic flowers, which were long-styled, mid-styled & short-styled, in correspondence with the perfect flowers.3

Now I am anxious to know whether the cleistogamic flowers on other tri-morphic species of Oxalis exhibit the 3 forms, or whether, as I shd have anticipated, all resemble one another.

I shd have said that I have reason to believe that other trimorphic species of Oxalis do produce cleistogamic flowers— Will you therefore kindly look in the Herbarium at any of the commoner trimorphic species from the C. of Good Hope or S. America, & see if you can discover any cleistogamic flowers. If so, & if you can spare me a specimen, pray mark whether it comes from a long-styled, mid-styled or short-styled plant— You must not waste much time about this; but the point seems to me worth determining.

Believe me with many thanks | yours very sincerely | Charles Darwin


Oliver had discussed cleistogamy in his article ‘Dimorphic flowers’ (Oliver 1864, pp. 245–6), published in the Natural History Review, April 1864.
Francis Darwin was CD’s secretary and assistant. Oliver evidently sent specimens of some species of Oxalis, but no list has been found. CD discussed several species in Forms of flowers; for a list see ibid., p. 350.
George Henry Kendrick Thwaites, director of the Peradeniya botanic gardens, Ceylon (Sri Lanka), had apparently sent the flowers of Oxalis sensitiva (a synonym of Biophytum sensitivum) several years earlier (see Correspondence vol. 25, letter to G. H. K. Thwaites, 26 March 1877).


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

Forms of flowers: The different forms of flowers on plants of the same species. By Charles Darwin. London: John Murray. 1877.

[Oliver, Daniel.] 1864a. Dimorphic flowers. Natural History Review n.s. 4: 243–8.


Enquiring about cleistogamic flowers of Oxalis.

Letter details

Letter no.
Charles Robert Darwin
Daniel Oliver
Sent from
Source of text
Newcastle University Special Collections (Spence Watson/Weiss Archive GB186 SW/6/6)
Physical description
4pp LS(A)

Please cite as

Darwin Correspondence Project, “Letter no. 10887F,” accessed on 4 June 2023,