skip to content

Darwin Correspondence Project

From Henry Reeks   3 April 1879

Thruxton, | nr. Andover—

April 3. ’79

Dear Mr Darwin.

Enclosed you will find a sample of seeds of Onobrychis sativa containing a few seeds also of Poterium muricatum.1 By this post I also send you some young plants of each of the above species found growing intermixed this morning. I fancy that it is such a perfect case of mimicry among plants that I have much pleasure in calling your attention to the following facts:—

Commencing with the seed you will observe (of course setting aside the botanical eye) how very difficult they are to separate by appearance. The burnet seeds are even “pitted”; and, although “angled”, only one angle catches the eye at the same time. I may here say that I have purposely left in more seeds of Poterium than are usually found in a carefully winnowed sample of sanfoin seed: the average would scarcely be three burnet seeds in half a pint of sanfoin seed, which would of course make the seeds of the useless plant more difficult to detect. Coming now to the young plants you will observe how wonderfully they still resemble each other; and it is next to impossible for any save the botanist, or experienced agriculturalist to weed out the burnet from the sanfoin: because we must bear in mind that we have not got the plants in our hands for seperation: they are growing together at our feet! When viewed from a distance of five or six feet I know of no leaves so dazzling, or difficult to grasp the outline of as those of pinnated form, especially when walking over a large surface of ground—like a field of sanfoin—carpeted with them. One would, however, naturally suppose that, as the plants belong to different natural orders the difference could be easily detected by the merest tyro when the plants are in bloom, but such is not the case,—far from it—the long pendulous pink stamens make it resemble, to a remarkable degree, the heads of flowers of Onobrychis2 I should be very delighted to hear your valued opinion as to its being a case of mimicry.

and with kind regards, | Believe me, very truly yrs. | Henry Reeks—

C. Darwin, Esqre F.R.S. &c.

Footnotes

Onobrychis sativa is a synonym of Onobrychis viciifolia, the perennial legume sainfoin. Poterium muricatum is a synonym of Sanguisorba minor ssp. balearica, the small burnet.
Sainfoin is in the order Fabales, and burnet in the order Rosales.

Summary

Sends a sample of seeds of Onobrychis sativa and Poterium muricatum, plants that show mimicry.

Letter details

Letter no.
DCP-LETT-11974
From
Henry Stephen (Henry) Reeks
To
Charles Robert Darwin
Sent from
Thruxton
Source of text
DAR 176: 83
Physical description
ALS 4pp

Please cite as

Darwin Correspondence Project, “Letter no. 11974,” accessed on 28 March 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-11974.xml

letter