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Darwin Correspondence Project

From W. H. Leggett   15 January 1877

224, E. 10th St., New York,

Jan. 15th, 1877.

Mr. Chas. Darwin,

Dear Sir,

Dr. Asa Gray has requested me to write to you what I know about Pontederia cordata L. In the Bulletin of the Torrey Botanical Club, Vol. VI. p. 62, I gave an account of my imperfect observations and expressed a hope of learning something more the next season.1 But I had no opportunity to study the growing plant last summer, and can add little to what was then noted.

The style till after the closing of the flower is intermediate in length between the two sets of stamens. The flower in withering twists up on itself and remains as a sort of button while the ovary enlarges. If when the ovary is well advanced one of these buttons be carefully unfolded,—a difficult matter on account of the decay of the perianth—the style will be found to have considerably elongated, and even to protrude sometimes from the button. But, as it is at this period in a florrid condition, the elongation can have nothing to do with the fertilization, and is perhaps merely the stretching produced by the twisting of the flower, at least, I can see no better means of accounting for it, though not at all satisfied with this.

As the plant is a social one and on the same spike there is a constant succession of flowers in all stages, it would seem likely that cross fertilization might take place without any special arrangement. But the fact that in this family there is a marked difference in the anthers of the same flower, and in this species in particular a very curious difference in the pollen grains, we are led to look for some complexity in the generation.

I suppose you have access to Dr. Torreys Flora of the State of New York prepared for the Geological Survey of the State, in which I think will be found a fuller account of our Ponterdiaceæ than in Grays Manual.2 A friend procured for me last Summer a supply of Schollera grammêa Willd. but I found in them no fourth flower which is said sometimes to occur.3

I enclose some of the Schollera, and Ponterderia in different stages. You will please notice that it is only the nearly ripe ovaries which have the longer styles.

Nothing would give me greater pleasure than to be of any service to your valuable investigations, and you will oblige me by showing me how.

Yrs truly, | Wm. H. Leggett


In a letter of 4 December 1876 (Correspondence vol. 24), CD had asked Gray whether he knew of any dimorphic plants that inhabited water or marshes, adding that he hoped some assistants could look for such specimens. Pontederia cordata (pickerel weed) is an aquatic plant found from eastern Canada to eastern South America. In Forms of flowers, pp. 183–7, CD described flowers of some species of Pontederia as heterostyled trimorphic based on observations of three species made by Fritz Müller in Brazil. He also referred to Leggett’s description of P. cordata in the Bulletin of the Torrey Botanical Club (Leggett 1875; see Forms of flowers, p. 187).
The description of the genus Pontederia by John Torrey (Torrey 1843, 2: 312–14) is similar to that in Gray’s Manual of botany of the northern United States (A. Gray 1848, pp. 509–11), but his description of P. cordata is more detailed as is his description of other species in the family Pontederiaceae.
Schollera graminea Willd. (a synonym of Heteranthera dubia, water stargrass) is also in the family Pontederiaceae. Leggett may have intended to refer to a fourth stamen rather than flower, as the species is described by Torrey and Gray as having usually three, but sometimes four stamens (Torrey 1843, 2: 314 s.v. Heteranthera graminea, A. Gray 1848, p. 511; Gray mentions the fourth stamen is abortive).


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

Forms of flowers: The different forms of flowers on plants of the same species. By Charles Darwin. London: John Murray. 1877.

Gray, Asa. 1848. A manual of the botany of the northern United States, from New England to Wisconsin and south to Ohio and Pennsylvania inclusive. Boston and Cambridge: James Monroe and Company. London: John Chapman.

Leggett, William Henry. 1875. Pontederia cordata, L. Bulletin of the Torrey Botanical Club 6 (1875–9): 62–3.

Torrey, John. 1843. A flora of the state of New-York, comprising full descriptions of all the indigenous and naturalized plants hitherto discovered in the state; with remarks on their economical and medicinal properties. Pt 2 of Natural history of New York. 2 vols. Albany: Carroll and Cook, printers to the Assembly.


At Asa Gray’s request, writes what he knows about Pontederia cordata.

Letter details

Letter no.
William Henry Leggett
Charles Robert Darwin
Sent from
New York
Source of text
DAR 109: B127–8
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 10790,” accessed on 22 February 2020,