RECORD: Darwin, C. R. [1864].08.23-28. Bignonia unguis. CUL-DAR157.1.118. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 4.2023. RN1
NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here.
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". Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin.
[118]
Aug 23d.
Bignonia unguis
The young leaves have between each pair a minute tendril, which in my plant has dropped off in all old leaves. Tendril represents lateral & terminal leaflet.— In one instance a little stick to peduncle slowly in course of 24° caused the whole foot to curl over like foot of bird in perching on branch, but did not clasp securely or well.— stick between toes caused no effect.— Rudimentary tendril?? a rare very peculiar habit?? Whole tendril a little above 4/10 of inch in length, of which peduncle rather above half.— The 3 toes equally divergent, equal in length, with tips curved at right angles & extremely sharp & hardened like hardest thorns! like falcons foot with no hind toe.—
/over
[118v]
The tendril which bent does never get straight — I now find that tendrils act well as grapnels to catch edges of leaves. They live beneath the pair of leaves. — They are developed very young so as to project beyond leaves hardly opened. — The most useless of tendrils — perhaps drop off if not become attached—
Tendrils would not help move these thorns.
No movement of leaves or internodes: no I think there is —
The 3 toes never seem to move separately; but together with peduncle they become curved downwards.
I now feel sure that touch does cause slowly curvature
Aug. 27. Young internode first moved from light, & then made a small irregular circle in 12°, & late at night moved to window.—
Aug 28th made an oval circle in 4° 20', but not quite complete then made quite a small circle.— Movements very irregular—
What small use in movement of internodes ∟ for so slight movement in tendrils Certainly are Movements in tendril
Bignonia
When branches thrown on tree certainly act like grapnels on edges of leaves
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 20 July, 2023