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Darwin Correspondence Project

From George Bentham   15 February 1880

25, Wilton Place. | S.W.

Feby 15/80

My dearest Darwin

If you do not object would you kindly sign the enclosed and return it to me?1

I have been for the last four or five months at work at Orchideæ for Genera Plantarum and have been wonderfully assisted by your book on the fertilisation of Orchids.2 I had no idea that Lindley and Reichenbach together could have brought the order into such a state of confusion both as to generic limitation and terminology for both showed great ability and intimate knowledge of species.3 I am very glad that you have suppressed the term caudicle which is indiscriminately applied to three very different organs— in Neottieæ &c a true caudicle or tail-like end of the pollen mass—in Epidendreæ a portion of the pollen not consolidated into the pollen masses but connecting them—in Vandeæ what you much more correctly have styled the pedicel, being as you have shown a production of the rostellum   I should however prefer the term stipes for pedicel is I believe as generally restricted to the stalk of a single flower as petiole is to the stalk of a leaf whilst stipes is used more generally as the support of any organ.4

I do not like the term gland generally used for what you have called disk but there is some inconvenience in using the latter term on account of its being more generally applied sometimes to an expansion of the torus sometimes to the centre of the upper surface of a petal etc.— the appearance of the part in question of the pollinarium is not always that which we associate with the word gland, and only very rarely like that of a quoit but I cannot at present devise a better term than the usually adopted one of gland, which in botany has not any very definite meaning being applied in different instances to very different organs.5

Your labours have done so much to the elucidation of the very curious modifications of the fertilising apparatus in the Order that I trust you will excuse my troubling you with these observations in the hopes that if any improved terminology occurs to you you would kindly communicate it— I have still I have no doubt six months work before I can get through the Order. Hooker is working up the Palms6

Yours very sincerly | George Bentham


Bentham had sent CD the certificate proposing William Turner Thiselton-Dyer for election as a fellow of the Royal Society of London (letter to George Bentham, 16 February 1880). The certificate was read to the society on 19 February 1880 and Thiselton-Dyer was elected 3 June 1880 (Royal Society archives, GB 117 EC/1880/07).
The section on the order Orchideae (a synonym of the family Orchidaceae) appeared in volume 3 part 2 of Genera plantarum published in 1883 (Bentham and Hooker 1862–83, 3: 460–636); Bentham published a summary of his classification in 1881 (Bentham 1881). Orchids was first published in 1862; the revised edition appeared in 1877 (Orchids 2d ed.).
John Lindley’s The genera and species of orchidaceous plants (Lindley 1830–40) was one of the earliest attempts to systematise orchids; Bentham significantly reduced the number of orchid genera recognised by Lindley as well as subsuming some of Lindley’s tribes within others and introducing subtribes (see Bentham 1881, pp. 285–7). Heinrich Gustav Reichenbach never published his own classification of orchids, but did publish a critical essay on the topic in 1885 (Reichenbach 1885).
Neottieae, Epidendreae, and Vandeae are orchid tribes recognised by both Lindley and Bentham (Lindley 1830–40, p. xvii; Bentham 1881, pp. 284–5). CD had differentiated the caudicle, an extension of the pollen mass, from the pedicel, an extension of the rostellum (a modified stigma; see Orchids, pp. 6–7). Modern orchid terminology, following Bentham, has referred to the supporting organ derived from tissue of the rostellum as the stipe (Dressler 1981, p. 315).
The torus or receptacle is the thickened stem tissue from which the floral organs grow. Some botanists had referred to the fleshy or glandular part of the receptacle as the disk (see, for example, MacGillivray 1840, p. 114). CD had called the portion of the rostellum which was attached to and removed with the pollen masses the ‘viscid disc’ (Orchids, p. 7). In modern orchid terminology, this is called the viscidium or viscid disk (Dressler 1981, p. 316).
Joseph Dalton Hooker’s section on the order Palmae (a synonym of the family Arecaceae) appeared in Bentham and Hooker 1862–83, 3: 870–948.


Bentham, George. 1881a. Notes on Orchideæ. [Read 20 January 1881.] Journal of the Linnean Society of London (Botany) 18: 281–360.

Bentham, George and Hooker, Joseph Dalton. 1862–83. Genera plantarum. Ad exemplaria imprimis in herbariis Kewensibus servata definita. 3 vols. in 7. London: A. Black [and others].

Dressler, Robert L. 1981. The orchids: natural history and classification. Cambridge, Mass., and London: Harvard University Press.

Lindley, John. 1830–40. The genera and species of orchidaceous plants. London: Ridgways.

MacGillivray, William. 1840. A manual of botany: comprising vegetable anatomy and physiology, or the structure and functions of plants. London: Scott, Webster, and Geary.

Orchids 2d ed.: The various contrivances by which orchids are fertilised by insects. By Charles Darwin. 2d edition, revised. London: John Murray. 1877.

Orchids: On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing. By Charles Darwin. London: John Murray. 1862.

Reichenbach, Heinrich Gustav. 1885. Ueber das System der Orchideen. In Bulletin du Congrès international de botanique et d’horticulture, réuni à St.-Pétérsbourg, le 5–15 mai 1884. St Petersburg: Imperial Academy of Sciences.


Has been at work on Orchideae for Genera plantarum and has found CD’s Orchids wonderfully useful. Comments on some problems of botanical terminology.

Letter details

Letter no.
George Bentham
Charles Robert Darwin
Sent from
London, Wilton Place, 25
Source of text
DAR 160: 171
Physical description
ALS 4pp

Please cite as

Darwin Correspondence Project, “Letter no. 12482,” accessed on 9 June 2023,