To Asa Gray   20 December 1876

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R.

Dec 20. 1876

My dear Gray.

Very many thanks about Hottonia.1 You mention Forsythia in the American Naturalist, and I have just examined dried flowers from Kew, & find that F. suspensa is beautifully dimorphic; so I have got a new family.2 I have been thinking about your proposed new terms, and I cannot for very shame change again   I have used this term in two or three printed articles, and it is used by several German & Italian writers. Kuhn objected to the term on the same ground as you do; but no one objects to Vertebrata, because it includes an animal without vertebræ. Moreover heterostyled seems to me more definite than heterogone, as the latter would apply to di & monœcious & to polygamous plants. I am of course not able to appreciate the difficulty of working in the term in systematic works; but Thwaites speaks of forma stylosa, & why may not a species be called hetero stylosa?3

However this may be it really would be too ridiculous for me to change again, so I remain Your affectionate & obstinate friend | Charles Darwin

LS

1
See letter from Asa Gray, 5 December 1876; Gray had provided information about Hottonia palustris (the water violet) and H. inflata (American featherfoil).
2
Gray had discussed evidence of dimorphism in Forsythia suspensa (weeping forsythia), and F. viridissima (green-stem forsythia), noting that only one form of each species existed in Cambridge, Massachusetts, in American Naturalist 7 (1873): 422–3. CD cited the note in Forms of flowers, p. 117.
3
See letter from Asa Gray, 5 December 1876 and n. 5. Friedrich Hildebrand had introduced the term ‘heterostyled’ to describe plants with two or three forms of flowers, having styles of different lengths relative to their stamens, in Hildebrand 1867. CD had used it in Variation 2d ed. and in Cross and self fertilisation. Max Kuhn had objected on the grounds that the differences between the flower-forms were not restricted to differences in length of style (Kuhn 1867, p. 66; see also Forms of flowers, p. 244). George Henry Kendrick Thwaites used stylosa and staminea (glossed as stylosa: with longer alternate stamens, shorter style, and staminea: with stamens of equal length, longer style) in his description of the two forms of Sethia acuminata (a synonym of Erythroxylum moonii) in Thwaites 1858–64, 5: 54; see also Forms of flowers, p. 122.

Please cite as “DCP-LETT-10728,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-10728