@misc{indiciaed77a0af10c52,
  title = {George Engelmann : botanical notebook 11 : Opuntia 1856-1882 — Illustration, [No.] 2564},
  year = {1869},
  url = {https://www.biodiversitylibrary.org/page/52850068},
  note = {Source identifier: page-52850068}
}