Refactor the unstructured text into a valid JSON dictionary. The key names follow the Darwin Core Archive Standard. If a key lacks content, then insert an empty string. Fill in the following JSON structure as required: {"catalogNumber": "", "order": "", "family": "", "scientificName": "", "scientificNameAuthorship": "", "genus": "", "subgenus": "", "specificEpithet": "", "verbatimTaxonRank": "", "infraspecificEpithet": "", "identifiedBy": "", "recordedBy": "", "recordNumber": "", "verbatimEventDate": "", "habitat": "", "occurrenceRemarks": "", "associatedTaxa": "", "country": "", "stateProvince": "", "county": "", "municipality": "", "locality": "", "decimalLatitude": "", "decimalLongitude": "", "verbatimCoordinates": "", "minimumElevationInMeters": "", "maximumElevationInMeters": ""}
  61DU J.E. Eckenwalder  Ob[:z 1935-07-31    Z Salicaceae    cR north of South Lae. South of Escanaba  < populus  UNITED STATES C/    @ in lowland f0rest,     Fu 1571 balsamifera grC+    aD/7U carl o. grassl  V;Ek+ 1221937  Malpighiales i  Lw    n x   L. delta k. 
{"catalogNumber": "1221937", "order": "Malpighiales", "family": "Salicaceae", "scientificName": "", "scientificNameAuthorship": "L.", "genus": "Populus", "subgenus": "", "specificEpithet": "balsamifera", "verbatimTaxonRank": "", "infraspecificEpithet": "", "identifiedBy": "J.E. Eckenwalder", "recordedBy": "Carl O. Grassl", "recordNumber": "1571", "verbatimEventDate": "1935-07-31", "habitat": "In lowland forest,", "occurrenceRemarks": "", "associatedTaxa": "", "country": "United States", "stateProvince": "", "county": "Delta", "municipality": "", "locality": "north of South Lake. South of Escanaba", "decimalLatitude": "", "decimalLongitude": "", "verbatimCoordinates": "", "minimumElevationInMeters": "", "maximumElevationInMeters": ""}