From W. T. Thiselton-Dyer   20 October 1875

Royal Gardens Kew

Octr. 20. 75

Dear Mr Darwin

I have been looking with Prof. Oliver at the specimens of the Saharunpore Hibiscus.1 Assuming that the facts are as they have been stated it is a very striking case indeed. Hibiscus tricuspis is indigenous in the Pacific Islands whence according to Roxburgh it was introduced into India.2 There it produces a sport according to Mr Bell and Dr King which appears to Prof. Oliver and myself identical with the Hibiscus tiliaceus which is indigenous in India.3

Now it is an empirical fact which has come out in the sorting of large collections of plants in the Kew Herbarium that the foliage of plants growing in islands has a tendency to be heteromorphic—that is to say plants with entire leaves are apt to produce divided leaves. This is especially the case with the collections recently made at Rodriguez.4 According to Dr Hooker5 it is also true for New Zealand. It is difficult to see any reason, but the fact seems to rest on a sufficient basis.

incomplete

CD annotations

1.1 I have … India. 1.6] crossed blue crayon
2.1 Now it is] opening square bracket blue crayon
Top of letter: ‘Leaves on Insular Plants often divided | Effects of Conditions’ blue crayon
End of letter: ‘(T. Dyer)’ blue crayon
1
George King had sent CD from the botanic garden at Saharunpore (now Saharanpur) in India specimens of a hibiscus (Hibiscus tricuspis or Paritium tricuspe) that had apparently produced a sport resembling a different species. Hooker had taken the specimens with him after visiting CD on 10 October 1875. See letter from J. D. Hooker, 14 October 1875 and n. 2; see also letter to J. D. Hooker, 15 October [1875] and n. 5. Daniel Oliver was keeper of the herbarium at the Royal Botanic Gardens, Kew.
2
In Flora Indica (Roxburgh 1832, 3: 202), William Roxburgh noted that seeds of Hibiscus tricuspis (now Talipariti hastatum, Tahiti hibiscus) had originally been sent by missionaries from Otaheite (Tahiti) to the botanic garden in Calcutta.
3
William Bell’s letter of 29 March 1863, describing the sport of Hibiscus tricuspis in botanic garden at Saharunpore, was published in Transactions of the Botanical Society 8 (1860–3): 565–6. CD had referred to Bell’s description in Variation 1: 377. CD added a reference to observations of the same plant made by George King to Variation 2d ed. 1: 402. Hibiscus tiliaceus (a synonym of Talipariti tiliaceum, beach hibiscus) is native to coastal areas of the Indian Ocean and western Pacific Ocean (Fryxell 2001, p. 260).
4
Rodriguez is one of the Mascarene Islands in the Indian Ocean, east of Madagascar. The Tahitian species of hibiscus (see n. 2, above) had three-lobed leaves while the species native to coastal India had heart-shaped ones.

Please cite as “DCP-LETT-10206,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-10206