RECORD: Darwin, C. R. [1864].08.26-29. Clematis flammula. CUL-DAR157.1.74-75. (John van Wyhe ed., 2002-. The Complete Work of Charles Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 4.2023. RN2
NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin.
The volumes CUL-DAR157.1-2 contain notes, abstracts etc. for Darwin's long paper and later book Climbing plants (1865). It was also commercially available as a softbound offprint, F834, F834a. See R. B. Freeman's bibliographical introduction. Items CUL-DAR157.1.11-60 were in a folder marked "Twiners". Items CUL-DAR157.1.61-112 were in a folder marked "Leaf-climbers" and items CUL-DAR157.1.114-147 were in a folder marked "Tendrils".
[74a]
(1
Clematis flammula
Aug. 26. Peduncles of le whole leaf & side leaflets very long — opposite & alternate so second good circle.— [sketch]
Bent stems t so act as grapnel— say oddly bent at each point, where pair of leaflets arise.
Until peduncles separate from each other not sensitive; when lamina of leaf is 1/4 of inch in length, (full sized leaf being 1 1/2 inch long) the peduncles being in proportion to lamina much more developed is period of most sensitiveness.—
The internodes do not move, so (& it wd be injury if did move) & are not sensitive.
The peduncle of one young leaf (lamina 1/4 inch) had certainly just perceptibly curled bent round stick in 3°. 15'; in another case in 5°. 30', rather
[74av]
Observe as peduncles when once twisted cannot again straighten themselves, it wd be very bad if transient regression caused movement. Hence no use sweeping of internodes
[74b]
(2
Clematis flammula
more plainly; & in this latter case peduncle was well curled in 1 round stick in 12°.
A leaf with leaflets 1/2 inch long, just perceptibly curled in 12° & plainly in 24°.
Certainly in 19°— now a loop of 9 inches of strong, caused terminal peduncle & 2 later peduncles of leaves to curl in.
In 6°. 40 six inches of string. I could just barely perceive upward curvature from 6 in terminal peduncle in from 6 inches of string; in 11° a great movement in 24° the peduncle formed a perfect open ring round string: — (30 inches weigh 5.18 gr. — Therefore 6 inches weigh nearly 1.04 (& 3 inches weigh 0.52 gr.) — The six inches had caused X in 48° the peduncles almost to touch the string all round. In 72° the open ring had seized the thin twine so that it cd be drawn out with force.
[75a]
(3
Clematis flammula
Aug. 29th. Three inches of string put on peduncle of one of lateral terminal peduncle caused just perceive change in 14° —; in 24° the peduncle had moved curved backwards 90 degrees, the string lying in angle between it & main peduncle: in another hour or two was pressed tight.
I suspect thickness of string acts, more than weight, for in tying on strong a tail hang down, intertwined amidst peduncle of not very young leaf & in no part stra pulled straight with end hitched to branch but this flexuous but of loose twine happened to hang obliquely not nearly perpendicularly across a peduncle, & in 48° produced some effect; in 6 3 days the end of peduncle had doubled back nearly parallel to base.—
[75b]
(4
Clematis flammula
I have now tried fragment of microscopical glass fixed on summit of it & cause peduncle to bend quick as opake stick.—
Six inches of cotton thread (standard weight) caused peduncle to bend certainly & discernibly in 48° probably before; but at this date certain
In 53° peduncle a semicircle; but subsequently no further movement if any change peduncle slightly straightened itself — This if minimum of excitement.
Aug 27th I took away sticks round which during 24° peduncle had wound, & now 31st they have not straightened themselves at all
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 13 January, 2026