@misc{indiciae5c42bfd3652a,
  title = {George Engelmann : botanical notebook 9 : Echinocereus, Cereus, Eulychnia, Pilocereus — Illustration, [No.] 2109 2 / [No.] 2109 [1] verso},
  year = {1869},
  url = {https://www.biodiversitylibrary.org/page/56134352},
  note = {Source identifier: page-56134352}
}