4. J. M. Rodwell to F. Darwin, 8 July 1882 (DAR 112: 94v); Correspondence 1: 125, n2.
5. C. R. Darwin to R. W. Darwin, 31 August 1831, DCP-LETT-110; Correspondence 1: 132.
6. C. R. Darwin, Galápagos Notebook, p. 30b; Chancellor and van Wyhe 2009, p. 418.
7. C. R. Darwin, 1845 (Journal of Researches), p. 392.
8. C. R. Darwin to J. D. Hooker, 12 December 1843, DCP-LETT-722; Correspondence 2: 419; J. D. Hooker to C. R. Darwin, [12 December 1843–11 January 1844], DCP-LETT-723; Correspondence 2: 421.
9. C. R. Darwin to J. D. Hooker, 5 June 1855, DCP-LETT-1693; Correspondence 5: 343.
14. M. S. Wedgwood to C. R. Darwin, [before 4 August 1862], DCP-LETT-3681; Correspondence 10: 351; C. R. Darwin to K. E. S. Wedgwood, L. C. Wedgwood, and M. S. Wedgwood, 4 August 1862, DCP-LETT-4373; Correspondence 10: 355. See also Wedgwood 1868.
15. C. R. Darwin to A. Gray, 28 October 1876, DCP-LETT-10656; Correspondence 24: 325.
16. Edens-Meir and Bernhardt 2014 for the authoritative treatment of Darwin’s orchid research and orchid biology
17. Nora Barlow (ed.). 1958. The Autobiography of Charles Darwin 1809-1882. London: Collins, p. 134.
18. C. R. Darwin to J. D. Hooker, 14 July 1863, DCP-LETT-4241, Correspondence 11: 533; C. R. Darwin to D. Oliver, 18 July 1863, DCP-LETT-4244, Correspondence 11: 543; C. R. Darwin to A. Gray, 4 August 1863, DCP-LETT-4262, Correspondence 11: 581
19. Isnard and Silk 2009 give a concise overview of research on climbers from Darwin to the present day.
22. C. R. Darwin to J. D. Hooker, 25 [and 26] January 1862, DCP-LETT-3411; Correspondence 10: 47–49.
23. Wallace 1867, p. 488. This paper includes an illustration of the predicted moth pollinating A. sesquipedale. See also Arditti et al. 2012 and Kritsky 1991 for interesting treatments of the comet orchid pollinator story.
CHAPTER 2—ARACHIS
24. C. R. Darwin to J. D. Hooker, 25 March 1878, DCP-LETT-11443; Correspondence 26: 138–139.
26. C. R. Darwin to A. Gray, 28 May 1864, DCP-LETT-4511; Correspondence 12: 211–214.
CHAPTER 4—CARDIOSPERMUM
27. For accounts of Soapberry bug biology and research, see entomologist Scott Carroll’s informative website on Soapberry Bugs of the World (soapberrybug.org) and Caroll and Loye 2012.
28. C. R. Darwin to J. D. Hooker, 31 May 1864, DCP-LETT-4516; Correspondence 12: 224–225.
CHAPTER 5—CATASETUM
29. See Romero-Gonzalez 2018 for an in-depth account of Darwin’s interest in these orchids.
53. See Costa 2017, chapter 6 for an account of this and other experiments in cross-pollination by Darwin.
CHAPTER 13—DIONAEA
54. T. Slaughter, ed., Bartram: Travels and Other Writings (New York: Library of America, 1996), p. 17. The quotation is found on pp. xx–xxi in the original 1791 edition of Bartram’s Travels. An electronic transcription of the 1791 text can be found in the Documenting the American South collection of the University of North Carolina-Chapel Hill Libraries (docsouth.unc.edu).
55. C. R. Darwin to D. Oliver, 29 September 1860, DCP-LETT-2941; Correspondence 8: 398.
56. Insectivorous Plants (1875), p. 286. See chapter 8 in Darwin’s Backyard (Costa 2017) for more on Darwin’s adventures with Venus’s fly-trap and other carnivorous plants, and Forterre et al. 2005 for an innovative study of trap closure using high-speed video and microscopy.
CHAPTER 14—DROSERA
57. C. R. Darwin to J. D. Hooker, 11 September 1862, DCP-LETT-3721; Correspondence 10: 401–404.
72. Darwin 1862b (van Wyhe 2009, pp. 322–323); see also Correspondence 10: 559.
73. For more on Darwin’s experimental technique tracing movement see David Kohn’s article in Darwin’s Garden: An Evolutionary Adventure (Kohn 2008), and Mea Allen’s Darwin and His Flowers (Allen 1977), p. 279.
CHAPTER 18—GLORIOSA
74. See Janet Browne’s “Botany for gentlemen” (1989) for an interesting analysis.
79. See Almaguer et al. 2014 for an overview of brewing with hops.
CHAPTER 20—IPOMOEA
80. See The Effects of Cross and Self Fertilisation in the Vegetable Kingdom (1878), pp. 15–18; C. R. Darwin to F. Galton, 13 January 1876, DCP-LETT-10357; Correspondence 24: 14–16.
81. Darwin 1878 [Cross and Self Fertilisation] p. 439.
CHAPTER 21—LATHYRUS
82. F. Darwin to C. R. Darwin, 14 August 1873, DCP-LETT-9009F; Correspondence 21: 329–330; C. R. Darwin to F. Darwin, 15 August 1873, DCP-LETT-9014; Correspondence 21: 334–336; F. Darwin to C. R. Darwin, 25 August 1873, DCP-LETT-9016; Correspondence 21: 348–349.
84. C. R. Darwin to F. Delpino, 1 May 1873, DCP-LETT-8892; Correspondence 21: 198–199; F. Delpino to C. R. Darwin, 18 June 1873, DCP-LETT-8945; Correspondence 21: 258–260; C. R. Darwin to F. Delpino, 25 June 1873, DCP-LETT-8951; Correspondence 21: 264.
94. A. Gray to C. R. Darwin, 28 December 1875, DCP-LETT-10329; Correspondence 23: 515–516; C. R. Darwin to A. Gray, 28 January 1876, DCP-LETT-10370; Correspondence 24: 31–32.
CHAPTER 26—MIMOSA
95. E. Darwin 1791 (The Loves of the Plants, “Canto I,” lines 301–302).
96. C. R. Darwin to J. D. Hooker, 12 September 1873, DCP-LETT-9052; Correspondence 21: 378–379.
124. See “Questions for William Herbert,” 1 April 1839, DCP-LETT-502; Correspondence 2: 179–182; and Herbert’s reply: W. Herbert to J. S. Henslow, 5 April 1839, DCP-LETT-503; Correspondence 2: 182–185.
125. See Barrett et al. 1987, Q&E 11 and T151 (pp. 501, 469). See also Abberley & R. Darwin to C. R. Darwin, 18 October 1841, DCP-LETT-610; Correspondence 2: 306.
CHAPTER 35—PRIMULA
126. Origin, pp. 49–50; see also Costa 2009 for additional explanatory notes on this passage.
130. C. R. Darwin to A. Gray, 19 Oct 1865, DCP-LETT-4919; Correspondence 13: 274–277.
CHAPTER 37—SALVIA
131. Darwin 1876 [Cross and Self Fertilisation] p. 5
132. F. Hildebrand to C. R. Darwin, 21 June 1864, DCP-LETT-4542; Correspondence 12: 254–255; C. R. Darwin to F. Hildebrand, 25 June 1864, DCP-LETT-4545; Correspondence 12: 256–257. Hildebrand published the results of this research in volume 4 of the Jahrbücher für wissenschaftliche Botanik (Hildebrand 1866).
137. C. R. Darwin to A. Gray, 31 October 1860, DCP-LETT-2969; Correspondence 8: 451–454; A. Gray to C. R. Darwin, 5 September 1862, DCP-LETT-3712; Correspondence 10: 394–395.
CHAPTER 40—TRIFOLIUM
138. C. R. Darwin to J. D. Hooker, 11 September 1859, DCP-LETT-2490; Correspondence 7: 332. The results of this experiment are also given in Darwin’s Experimental notebook (DAR 157a), pp. 46–47.
140. For additional explanatory notes on these passages, see Costa 2009.
141. C. Hardy to C. R. Darwin, 23 July 1860, DCP-LETT-2877; Correspondence 8: 300–301; C. R. Darwin to C. Hardy, 27 July 1860, DCP-LETT-2879; Correspondence 8: 301.
142. C. R. Darwin to J. Lubbock, 2 September 1862, DCP-LETT-3708; Correspondence 10: 387–388 and 3 September 1862, DCP-LETT-3705; Correspondence 10: 392.
143. C. R. Darwin to F. Darwin, 25 July 1878, DCP-LETT- 11631; Correspondence 26: 320–322.
CHAPTER 41—TROPAEOLUM
144. Elisabet Christina Linnaea’s paper “Om Indianska Krassens Blickande” (“On the twinkling of Indian Cress”) was published in volume 23 of Kongl. Vetenskaps Academiens Handlingar (Acts of the Royal Swedish Academy of Sciences), 1763, 23: 284–286, along with commentary by physicist Johan Carl Wilcke on electrical phenomena (1763, 23: 286–287).
145. E. Darwin: The Loves of the Plants, “Canto IV,” lines 43–51 (see E. Darwin 1806, pp. 191–192).
146. S. T. Coleridge, “Lines Written At Shurton Bars, Near Bridgewater, September, 1795, In Answer To A Letter From Bristol,” published in Poems on Various Subjects (Coleridge 1796).
155. C. R. Darwin to J. D. Hooker, 30 May 1862, DCP-LETT-3575; Correspondence 10: 226–227.
CHAPTER 45—VITIS
156. C. R. Darwin to J. D. Hooker, 27 January 1864, DCP-LETT-4398; Correspondence 12: 31–33.
157. C. R. Darwin to D. Oliver, 11 March 1864, DCP-LETT-4424; Correspondence 12: 68–70; D. Oliver to C. R. Darwin, 12 March 1864, DCP-LETT-4425; Correspondence 12: 71–73.