Botanists are obliged to regard tendrils as either leaf- or stem-formations. Vitis, Passiflora, and Clematis are discussed. [See 4398.]
Botanists have no choice but to regard some tendrils as leaf—, & others as stem-formations.
In Vitis there seems no room whatever for a doubt but that the tendril is an
axial or stem-structure. Analogy with other plants buildt up of similar
sympodia—as they are called—or superimposed axes—& espec
Passiflora is much more perplexing. From analogy I sh
Some, however, do look as tho' they might be axillary branches. They may, however, be
the modified first leaf of an axill
I do not recollect seeing any clear discussion about Passion-flower tendrils & have carefully examined them.—
Clematis. The genus Naravelia (close to Clematis) has the terminal leaflet & upper lateral leaflets converted into tendrils like Pea.
- f1 4398f.f1The date is established by the relationship between this letter, the enclosure attached to the letter to J. D. Hooker, [27 January 1864], and the letter to J. D. Hooker, [8 February 1864].
- f2 4398f.f2See letter to J. D. Hooker, [27 January 1864] and nn. 19--22.
- f3 4398f.f3Sympodium: `An apparent axis or stem in a dichotomously branched plant, made up of the bases of successive branches so arranged as to resemble a simple or monopodial axis' (OED).
- f4 4398f.f4Oliver is comparing Passiflora tendrils with those of gourds, a member of the Cucurbitaceae. For a definition of `axillary', see the letter to David Oliver, 11 March  and n. 7; see also letter from Daniel Oliver, 12 March 1864 and n. 4.
- f5 4398f.f5For CD's eventual conclusions about the genesis of tendrils in the Vitaceae and in the Passifloraceae, which include passion flowers, see letter to J. D. Hooker, [27 January 1864] and n. 20. See also letter from Daniel Oliver, 12 March 1864.
- f6 4398f.f6Clematis and Naravelia were both members of the Ranunculaceae. For a reference by CD to Naravelia, see `Climbing plants', pp. 34, 112.