Much of Müller's botany was stimulated by the series of botanical works published by Darwin in the years after the "Origin". Müller made contributions in all these fields. After Darwin's "Fertilisation of Orchids" (1862) he spent years of work on orchids, sending observations to his brother Hermann and to Darwin. Darwin used some of this work in his second edition of 1877, and Hermann later became famous for his work on pollination. On "Climbing plants" (Darwin 1867) Müller sent a letter to Darwin listing 40 genera of climbing plants classified by their method of climbing. The next few months saw more observations, which Darwin had translated and published as Müller's first paper in English.