The date range is established by CD’s annotation ‘Shape of Stigma’ on the back of the cover of the letter from W. E. Darwin, 14 April [1864], and by William’s drawing of stigmas in his memorandum of 6 May 1864.

At some time, CD received seedlings of Pulmonaria angustifolia that William had collected from the Isle of Wight (see Correspondence vol. 11, letter to W. E. Darwin, [25 July 1863] and n. 3); in Forms of flowers, pp. 104 and 107, CD mentioned seedlings that he raised from Isle of Wight plants, and a note dated 6 May 1864 in DAR 110: A51 begins, ‘Pulmonaria I. of Wight in kitchen garden’.

CD also made this observation regarding style thickness in a note dated 6 May 1864 in DAR 110: A51, but, on the reverse side, CD recorded in a note dated 14 May that he now found that the thickness of style was ‘very variable’. In the note in DAR 110: A51, it was also written: ‘Stigma sometimes bi-lobed & sometimes not in long-styled [above del ‘both forms’]’; in Forms of flowers, p. 106, CD wrote: ‘The stigma varies in being more or less, though slightly, lobed.’

For William’s initial reply regarding stigma shape, see his memorandum of 6 May 1864; see also letter from W. E. Darwin, 12 May [1864] and n. 7.