From Asa Gray 29 July [1880]
July 29—
Thanks for your postal1
Ipomœa jalapa (Conv. I. macrorhizus. Ell.) of S. Carolina, with a large turnip-like root, sometimes 40–50 lbs, makes only moderately long petioles cotyledons & lengthens the caulicle considerably— — has not caught the trick, but has some idea of it.2
A. Gray
Footnotes
CD’s postcard has not been found, but see the letter from Asa Gray, 3 July 1880. Gray had written about germination in two species of Ipomoea.
Ipomoea jalapa is a synonym of I. purga (jalap), a species native to parts of Mexico. Ipomoea macrorhiza is largeroot morning-glory, a species native to South Carolina; Gray may have accidentally conflated the names, but evidently intended I. macrorhiza. In Gray’s usage, the caulicle was the initial stem in an embryo (A. Gray 1879, p. 401). The ‘trick’ refers to the method of germination, which, in the case of some other species of Ipomoea, involved the caulicle remaining shut while the petioles lengthened and brought up the cotyledons (letter from Asa Gray, 3 July 1880).
Bibliography
Gray, Asa. 1879. Gray’s botanical text-book. Vol. I. Structural botany or organography on the basis of morphology. To which is added the principles of taxonomy and phytography, and a glossary of botanical terms. 6th edition. New York and Chicago: Ivison, Blakeman, and Company.
Summary
Information about Ipomœa jalapa.
Letter details
- Letter no.
- DCP-LETT-12674F
- From
- Asa Gray
- To
- Charles Robert Darwin
- Postmark
- JUL 80
- Source of text
- DAR 186: 53
- Physical description
- ApcS
Please cite as
Darwin Correspondence Project, “Letter no. 12674F,” accessed on 20 May 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-12674F.xml
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