@misc{indiciaed9426ba46835,
  title = {George Engelmann : botanical notebook 9 : Echinocereus, Cereus, Eulychnia, Pilocereus — Illustration, [No.] 2157},
  url = {https://www.biodiversitylibrary.org/page/56154233},
  note = {Source identifier: page-56154233}
}