user: Question: How many tree species are listed when the total plant species is 258?
Columns: ['Central Forest Reserve', 'Size in km²', 'Total plant species', 'Tree species', 'Endemic', 'Threatened (CR,VU,EN)']
Types: ['text', 'real', 'real', 'real', 'real', 'real']
Sample row: ['Kashoya-Kitomi', 385.0, 901.0, 419.0, 41.0, 17.0]
SQL:

assistant: SELECT "Tree species" FROM "Table" WHERE "Total plant species" = 258.0;