Why a County Native Plant List Can Look Short (or Use the Whole State)
A county list is a record of who has looked
USDA's county records come from herbarium specimens and botanical surveys: someone found the plant there and documented it. A county that has been surveyed for a century can list over a thousand natives; a rural county few botanists have visited may list a fraction of what actually grows there. The typical county here has 498 natives on record.
Counties with thin records
189 counties have fewer than 150 plant records of any kind. Their pages keep the real county list, because it is still the best evidence of what grows there, but say plainly that it is a floor and show how many natives the whole state records. The thinnest are Kalawao County, Hawaii (1 record), St. Louis (city), Missouri (1 record), Portsmouth (city), Virginia (2 records).
Places with no county list at all
45 places return no plant records under their own name, so their pages use the statewide list instead and say so at the top. Most are not counties in the usual sense: 32 are Virginia independent cities, which have no plant records of their own in USDA's data; 9 are Connecticut's planning regions, which replaced its counties in census geography in 2022 and have no plant records filed under them; the rest are a few counties with no records under their current name. A state list is broader than any one place: some of those plants grow only on the coast, in the mountains, or at the far end of the state.
Reading a short list
Use it as a starting set, not a complete one. Neighbouring counties with the same soils and climate are a fair guide to what is missing, and the state list on a thin county's page shows the full range. A plant missing from a county list has simply not been recorded there; that is not evidence it would fail. Within the list you do have, only the rated plants can be matched to a spot, and the most widespread natives are the likeliest to be missing from the record rather than from the ground.