How to exclude introduced species from a query result

The following query returns all species of plants (with flower) observed in Vermont from January to May:,2,3,4&order=asc&order_by=observed_on&place_id=47&term_id=12&term_value_id=13&verifiable=any&view=species

However, some introduced species are included in the list despite the parameter introduced=false. How do I exclude ALL introduced species from the list? TIA

Adding &native=true seems to do it.,2,3,4&order=asc&order_by=observed_on&place_id=47&term_id=12&term_value_id=13&verifiable=any&view=species&native=true

Read more about it here:
The native and introduced search terms don’t always seem to work in an intuitive way.


&introduced=false finds taxa set to unknown, native, or endemic.
&native=true finds taxa set to native or endemic

Then why does adding both &native=true &introduced=false results in unknown, native, or endemic?

Yeah, I agree, it doesn’t make any sense, but it works for me! :-)

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Just keep in mind that there are a lot of native species on a lot of place checklists where Establishment Means is currently at the default “unknown” setting, and hasn’t yet been updated to “native” or “endemic.”

Using &native=true will exclude introduced taxa, but it will also exclude “unknown” taxa, some of which are really native.

So &native=true is not guaranteed to return a complete set of all native observations. It depends on the community maintaining and updating Establishment Means in place checklists.


After playing around with this some more, I’ve concluded that &native=true does not do what I want. The documentation suggests that &introduced=false finds taxa set to unknown, native, or endemic. I assume that’s equivalent to not introduced but it doesn’t seem to work that way. What am I doing wrong?

The query string at the very top of this thread (with parameter introduced=false) lists the following 7 introduced species:

If I remove the parameter introduced=false from the query string, 24 additional introduced species are listed. I won’t list them here but here is the URL:,2,3,4&order=asc&order_by=observed_on&place_id=47&term_id=12&term_value_id=13&verifiable=any&view=species

I would expect none of the 31 introduced species to be listed when the parameter introduced=false is added to the query string. Is this a bug?

I haven’t dug to the root of the problem, but I think the issue is that those taxa are marked introduced on the Vermont checklist, but not on the observations. For example,


I’m pretty sure this is leftover from the bug where changing the establishment means didn’t automatically re-index observations. That’s been fixed, but the fix wasn’t retroactive.

I re-indexed the observations that were causing problems for your particular search, but if you change the search parameters, for example by adding May, you’ll get more introduced species.

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Thanks for the explanation. It helps to know that I’m using the parameters correctly.

Why haven’t all observations been re-indexed? Are there just too many of them?

That would be my guess.

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