List taxa as invasive

It’s very helpful for me to learn which plants are introduced; however, I’m wondering about taking the next step and labeling plants as invasive. Eg, garlic mustard is a much bigger threat than the Western Honey Bee in my region, yet both are flagged as introduced.


i think “invasive” is a little too imprecise a term to be turned into a flag used by the masses. first, i don’t think people generally agree on what “invasive” means exactly. some folks define it to mean introduced + aggressive. some people say aggressive, regardless of native status.

“introduced” is easer to make a (binary) flag because it’s easier to determine whether something is native or not. however, because of the aggressiveness component, “invasive” tends to be less binary and better expressed on some sort of scale. (or at the very least, you would have to have some sort of standardizable threshold of aggressiveness to separate invasive from not invasive.)

finally, some people go with a guilty-until-proven-innocent approach, where if you don’t know how aggressive something is, then any introduced species is invasive until proven otherwise. others go with an innocent-until-proven-guilty approach. so that disagreement in approach another is challenge if you want to make an “invasive” flag.

that said, i have seen people create projects for managing invasive species in an area (ex. and also mark individual observations as invasive using an observation field (ex.


South Africa has this project


I mark invasive species by using the Observation fields, as @pisum mentioned! Here’s my methods:

My method for identifying invasive species has been to consult the invasive species lists specific for that state and the surrounding states, as well as the US noxious and invasive species lists. It’s a bit tedious to find all the various lists, but I just bookmark the webpages for my geographic region (southeast US) so I can consult them as needed. Each state/region has different requirements for deciding something is legally invasive, so there’s a lot of ambiguity around introduced species that are little to no threat to native species or are newly-introduced, but that’s another long conversation for a different thread.

My method for marking observations as invasive species is by using the “Observation Fields” feature (in the right hand column on the webpage, right above the top observers list. Unfortunately can’t access these observation fields and other annotations in the iPhone app while I’m in the field). There’s a couple different invasive labels you can add, but my favorite is “Invasive?”. When you choose this option, there’s a dropdown menu with the options of “yes, no, maybe, or unknown”. I find this much more useful than just a straight yes or no, as I can mark plants that seem suspicious (or that are reported invasives in neighboring states but not yet reported in my state) as “maybe”.


Another example of a project that lists invasive species is


As @pisum says, the term “invasive” cannot be clearly defined so it’s not a term iNat will use for establishment means.

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