From W. E. Darwin 8 May [1863]1
Southampton
May 8.
My Dear Father,
I sent off this morning a box containing two heads of Anchusa.2 The pollen of short pistilled is decidedly the largest and there is most of it. I have entirely forgotten to look whether both bear seeds; but I will.3 I am going to the isle of Wight on Sunday when I will mark some plants.4
I know whether you have examined Corydalis carefully; it seems almost as nicely arranged as Orchis.5
The two side petals form a hood over stigma enclosing it entirely, as soon as the pollen is mature it all falls into the cuplike-stigma when enclosed by the hood, then the back petal that is the one facing the nectary petal falls back and leaves the pistil just on the balance within the hood. This back petal prevents the hood coming off the stigma and it never seems to fall back till the stigma cup is full of pollen.
As soon as the back petal falls back, the least touch sends out the pistil with a bound. Carrying the pollen with it the stigma and style on bounding out fit exactly into the groove leading down to the nectary. But instead of the stigma going straight into the groove from a natural twist in the style it goes in side ways, so that as it buries itself at base of groove nearly all the pollen is pulled out by the friction and is left against side of groove in position for bees to take it, at the same time leaving stigma almost bare to receive other pollen.
So as to prevent the proboscis penetrating except at proper side (or at base?) of groove there is curve in side of groove which makes a sort of overhanging ledge.
Is this the same in fumitories?6 As it is a beautiful arrangement making the pistil carrying the pollen in position for another flower.
I am glad to find you have managed to get to Leith hill.7
Your affect son | W. E Darwin
Tell me whether I am right about Corydalis
CD annotations
Footnotes
Bibliography
Forms of flowers: The different forms of flowers on plants of the same species. By Charles Darwin. London: John Murray. 1877.
Willis, John Christopher. 1973. A dictionary of the flowering plants and ferns. 8th edition. Revised by H. K. Airy Shaw. Cambridge: Cambridge University Press.
Summary
Describes the structure of Corydalis and its arrangement for making pollen accessible to bees.
Letter details
- Letter no.
- DCP-LETT-4147
- From
- William Erasmus Darwin
- To
- Charles Robert Darwin
- Sent from
- Southampton
- Source of text
- DAR 76: B188–90
- Physical description
- ALS 5pp †
Please cite as
Darwin Correspondence Project, “Letter no. 4147,” accessed on 1 September 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-4147.xml
Also published in The Correspondence of Charles Darwin, vol. 11