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": ""}
   Michigan U:y   -84.47713 U[L     F salix exigua     M exigua malpighiales -/|   . ;L GREEN ISLAND (OFF PT. LA BARBE). Salicaceae d  Nutt. 2Z   45.83549 T       gM] SALIX  1948-08-20 M  LOW GROUMD. `W/ ;       United States  % 533
{"catalogNumber": "", "order": "Malpighiales", "family": "Salicaceae", "scientificName": "Salix exigua", "scientificNameAuthorship": "Nutt.", "genus": "Salix", "subgenus": "", "specificEpithet": "exigua", "verbatimTaxonRank": "", "infraspecificEpithet": "", "identifiedBy": "", "recordedBy": "", "recordNumber": "533", "verbatimEventDate": "1948-08-20", "habitat": "Low ground.", "occurrenceRemarks": "", "associatedTaxa": "", "country": "United States", "stateProvince": "Michigan", "county": "", "municipality": "", "locality": "Green Island (off Pt. La Barbe).", "decimalLatitude": "45.83549", "decimalLongitude": "-84.747713", "verbatimCoordinates": "", "minimumElevationInMeters": "", "maximumElevationInMeters": ""}