@misc{indiciae494099073a39,
  title = {George Engelmann : botanical notebook 9 : Echinocereus, Cereus, Eulychnia, Pilocereus — Illustration, [No.] 2071},
  url = {https://www.biodiversitylibrary.org/page/56136785},
  note = {Source identifier: page-56136785}
}