To Daniel Oliver   2 September [1862]1

Cliff Cottage | Bournemouth | Hants.

Sept. 2d.

Dear Oliver.

I want very much to beg a favour. I have been working hard at Lythrum salicaria, which offers a most curious case (beating Primula all to bits) of trimorphism, & I hope my numerous crosses at home will explain the functional meaning of all the differences.2 This work has given me an intense wish to see fresh flowers of any member of the Lythraceæ. Have you anything in bloom at Kew?3 If so would you be so very kind as to send me anything in little tin by Post—tying something damp round cut off stems.— When you hear the case of Lythrum, I really think you will not think the trouble wasted.—4

We are here on account of a long miserable illness of one of my Boys from Scarlet Fever; & now my poor wife has caught it, but has almost recovered.—5 I have in consequence done hardly anything this summer.

Can you tell me of any plants, which bear differently coloured anthers? I wrote to Hooker & he could not remember any besides the Melastomas & Lythrums,6 & I have just seen in a garden a small bush, which seems to me either a Clarkia or Epilobium with crimson tall anthers & short white ones.—7 This difference I suspect would be good guide to functional dimorphism.—8

I hope you have enjoyed your holidays.— Hooker tells me you are at Kew, where I wrote to him about Lythaceæ.—9

Dear Oliver | Yours very sincerely | in Haste | C. Darwin

1
The year is established by reference to the incidence of scarlet fever among members of the Darwin family (see n. 5, below).
2
In his letter to Oliver of 29 [July 1862], CD had described the crosses he planned to make with Lythrum salicaria. The earliest of his notes from these experiments is dated 31 July 1862 (DAR 27.2 (ser. 2): 7).
3
Oliver was librarian and assistant in the herbarium at the Royal Botanic Gardens, Kew.
4
In a subsequent letter, which has not been found, CD described what he believed to be the relationship between the three sexual forms in this species; for Oliver’s response, see the letter from Daniel Oliver, 13 September 1862.
5
The Darwin family were on holiday in Bournemouth to assist with the convalescence of Leonard Darwin, who had been ill with scarlet fever since mid-June (see letter to W. E. Darwin, 13 [June 1862], and letter to H. C. Watson, 8 [August 1862]). Emma Darwin became ill with the disease on 13 August 1862, on the first stage of their journey to Bournemouth (Emma Darwin’s diary (DAR 242)).
7
In a note dated 25 September 1862 (DAR 48: 50), CD recorded the existence of two differently coloured sets of stamens in Clarkia pulchella, describing the shorter ones as ‘aborted with little shrivelled anther with no pollen’. He noted that the species presented a ‘good [case of] gradation’, marking his notes ‘Transition’: he apparently considered that the species was transitional between an ordinary hermaphrodite plant and a dimorphic plant. For CD’s later views on the origin of heterostyly, see Forms of flowers, pp. 260–8. See also letter from Daniel Oliver, 4 September 1862.

Please cite as “DCP-LETT-3706,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-3706