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": ""}
occasional shrub on upper beach K   Salix exigua J_T    a Mackinac   16144 3Pd s     nu7t. *X@g        t61  united states 1991-06- 07 !KT   exigua T<3[3   p Malpighiales  x4@p 45.82918   y+ MICHIGAN  - round island at sand bay near e end of n side of island.   
{"catalogNumber": "", "order": "Malpighiales", "family": "", "scientificName": "Salix exigua", "scientificNameAuthorship": "Nutt.", "genus": "", "subgenus": "", "specificEpithet": "exigua", "verbatimTaxonRank": "", "infraspecificEpithet": "", "identifiedBy": "", "recordedBy": "", "recordNumber": "16144", "verbatimEventDate": "1991-06-07", "habitat": "occasional shrub on upper beach", "occurrenceRemarks": "", "associatedTaxa": "", "country": "United States", "stateProvince": "Michigan", "county": "Mackinac", "municipality": "", "locality": "Round Island at sand bay near E end of N side of Island.", "decimalLatitude": "45.82918", "decimalLongitude": "", "verbatimCoordinates": "", "minimumElevationInMeters": "", "maximumElevationInMeters": ""}