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Darwin Correspondence Project

From Francis Darwin   14 August [1873]1

Pantlludw | Machynlleth

Aug 14

Dear Father

Mrs Ruck knew where the Lathyrus maritima grew so Amy & I railed off there; it is near a little place called Llwyngwril near Barmouth on the cliffs— We found it growing in tangled masses—most lovely tho’ it was rather passed. They have the nectar holes just like the ones in the everlasting pea—2 I saw a bee going to them & he went to a hole bitten in the base of the keel   Amy & I examined 24 flowers & found in 23 of them this hole was present & on the right hand side (looking at the flower from above). We therefore looked at the nectar holes of 24 of them and in 16 of them the right hole was biggest, in 2 equal or doubtful and in 6 the left bigger   The reason the right is bigger is that the pod in growing out of the stamen tube goes to the right of the loose stamen; and we think the reason of that is that the pod has a slight bend with the convexity towards the right. The right nectar holes is bigger than the left even before the splitting up caused by the growth of the pod. In the everlasting pea, the pod we think also goes to the right of the loose stamen, but the right hole we think isnt bigger till the splitting begins but we will look at a lot. Why should the bees bite the Maritima but go in the proper way pressing down the keel, in Everlasting Peas—3 They bite quite young buds in Maritima perhaps Maritima has honey in younger buds than the bee can get at in the legitimate way? I suppose you know all this, but it has been great fun discovering it— The droseras had their feed of bread yesterday— I have put bread on the damp moss beside them to compare— I shall look tomorrow.4 Tell Jim no family should be without his worm-garden— we have grt fun with ours— we take notes and take tracings of their burrows5   I think they will lay their eggs as I have two worms and they are in full breeding condition— We find they make a very curly burrow with a blind end and then somehow turn round with their heads towards the entrance   I think we shall make them out— They have made no castings in the surface of the earth but very small ones in the burrow itself

My love to mother & thank her for her letter— We send you a Maritima | Yrs affec F Darwin

CD annotations

1.10 loose stamen] ‘(not always)’ interl pencil
1.18 The droseras … Darwin 2.2] crossed pencil
Top of letter: ‘Lathyrus Maritimus’ pencil


The year is established by the relationship between this letter and the letter to Francis Darwin, 15 August [1873].
Lathyrus maritimus is now L. japonicus (the sea or beach pea). It is found rarely on shingle on the east and south coast of England (for distribution in the British Isles, see Randall 1977). Francis later found that the species he described was actually Lathyrus sylvestris (see letter from Francis Darwin, [16 or 17 August 1873]). The everlasting pea is either Lathyrus latifolius (the broad-leaved everlasting pea) or L. sylvestris (the narrow-leaved everlasting pea; now often called the flat pea); L. sylvestris is native to the British Isles, while L. latifolius, a popular garden plant, is naturalised in places (see J. D. Hooker 1870, p. 104). Francis also refers to Mary Anne and Amy Ruck.
It is now common to describe the orientation of flowers (right, left) from the viewpoint of a legitimate pollinator (that is, one that gets access to pollen and nectar in a way that results in the cross-pollination of flowers). Access to nectar through a hole would not result in pollination, so such visits are referred to as illegitimate. In papilionaceous flowers like those of Lathyrus, the petals are specialised. Two carina or keel petals form a boat-shape that encloses the sexual parts of the flower; two alae or wing petals are attached to the sides of the keel, and a large central vexillum or standard petal with line and colour guide-marks directs insects to the correct landing position to effect the transfer of pollen. For a detailed description of the floral morphology and kinetics of Lathyrus latifolius and its insect visitors, see Westerkamp 1993.
CD had resumed his experimental work on Drosera in mid-June (see ‘Journal’ (Appendix II)). He was studying the powers of digestion of D. rotundifolia and its reaction to various substances (see letter to Mary Treat, 12 August 1873).
‘Jim’ was a nickname for Horace Darwin (letter from Francis Darwin and Amy Ruck to Horace Darwin, [23 April 1873] (DAR 258: 790)). Amy had sent CD information on wormcastings in 1872 (see Correspondence vol. 20, letters from Amy Ruck to Horace Darwin, [20 January 1872] and [1 February 1872]).


Has found Lathyrus maritima on the cliffs near Barmouth.

Letter details

Letter no.
Francis Darwin
Charles Robert Darwin
Sent from
Source of text
DAR 274.1: 26

Please cite as

Darwin Correspondence Project, “Letter no. 9009F,” accessed on 25 June 2018,

Also published in The Correspondence of Charles Darwin, vol. 21