I feel like I’m fighting people on whether X or Y plant is wild or not on a regular basis, so I thought I’d raise a discussion. I developed this rating inspired by the BOU (British Ornithologist’s Union) in terms of how to decide if a plant “counts” as wild. Plants can be labelled from Category A to E depending on their circumstances. Here’s what I have so far:
Category A: Native and naturally occurring in the given circumstances.
Discussion: Plants that are considered native to the immediate area, such as within a county, or district.
Category B: Native, but no longer suspected to occur in the wild in the immediate area.
Discussion: This is a rare category, but necessary; it describes plants that may have diminished from human activities, or even gone extinct; their remaining presence is a result of captive populations. Most plants in this category are directly planted such as in botanic gardens, in which case they fall to Category E; however, they become countable as “wild” under Category B if spreading from plantings, such as from restoration sites.
Category C: Introduced but thriving, widespread dispersal without assistance across many habitat types.
Category C2: Localized introduction; dispersal present but limited to specific niches or habitat types.
Discussion: Most weeds fit into this category. The distinction between C and C2 is possibly too arbitrary to be useful.
Category D: A waif, usually occasional or a one-off, but with no evidence of planting. No parent plants known in the vicinity.
Category D2: A waif, not likely to be planted, but parent plants known and within 50 feet.
Category D3: Localized to known parent plants, such as saplings spreading from a parent tree. Generally within 15 feet of parents.
Discussion: This category applies to species that are usually considered non-wild, but are occurring in a manner suggesting they are not planted. For instance, plants occurring in unusual circumstances, such as a lone individual occurring within a neat row of planted shrubs, or plants that are an unintended addition to an otherwise manicured landscape.
Category E: A known planting, or otherwise highly likely to be planted (e.g. planted in a pattern, a species known to be sterile and/or regularly planted by humans, or seed mixes/wildflower packs). No evidence of reproduction, and circumstantially very likely to be planted.
Most databases would be willing to treat up to Category D(1). For iNaturalist, up to Category D3 fits the description of “wild”. However, for other sites like eBird, only Category C would be counted. I understand individual opinions vary, but this is some attempt to standardize these different circumstances.