We would all love to know where the various species of aster or goldenrod can be found and how common they are within a particular geographical area.  Unfortunately, that information is not easy to ascertain.  No one is able to visit every niche within the New England region.  Internet-based resources, such as the NatureServe website, the USDA Plants Database and the various state heritage program websites have improved tremendously in recent years, and they are quite useful.  However, none of them is completely accurate.  Moreover, the information they provide isn't consistent across the various websites.

The scope of this website is confined to the six states comprising the New England region.  This assemblage of political entities is admittedly artificial, for plant species know nothing of political boundaries.  Though it may be intellectually interesting to know the complete ecological range of any or all of the species described here, that is beyond the scope of this site.  NatureServe and the USDA Plants Database are the best sources for that type of information.

A number of systems for describing the rarity or abundancy of species have been devised.  The simplest and least accurate is the scheme used in some of the common field guides.  One may encounter something along these lines:   very common, common, locally common, uncommon, rare.  This scheme, while meaningful in some ways, is very imprecise.  At the very least, it would need to be qualified by specifying a particular geographic area:  "Solidago rugosa is locally common in Worcester County, Massachusetts."  That is, you'll find thousands of them in one town, but not a one 10 miles down the road.

Most states now have endangered species lists.  These lists use ranks or statuses to determine whether a species is afforded protection under the laws of that state.  This system is much more precise, for it is based on actual field surveys conducted by natural heritage program staff and other trained professionals or volunteers.  The criteria are usually based on the numbers of known populations of the various species.  For example, to be considered "Endangered" (Critically Imperiled) there would need to be fewer than 6 known populations of a particular species.  To be considered "Threatened" (Imperiled), there would need to be from 6 to 20 populations of a particular species in the state.  Similarly, to be considered "Of Special Concern", there would need to be greater than 20 known populations, but fewer than some higher number of populations, such as 80 or 100.

While the legislative ranks used by state governments are more precise than those used in field guides, they're not very useful for conducting the day-to-day business of state or national heritage programs.  So, a third scheme was adopted almost universally by state and national heritage programs to meet management and reporting demands.  Thus, we have the "S" ranks, "N" ranks and "G" (global) ranks which define the degree of rarity or abundance of particular species.  The "S" ranks are also based on numbers of known populations, so are fairly precise.  There are minor variations in these ranking schemes from state to state, but they are basically the same.

The most accurate sources are those found on the respective state heritage program sites,  for they are based on continual field surveys and periodic local review processes.  This is the scheme used here in this website.  Please refer to the State Status chart for descriptions of the "S" codes.

For convenience, I have relied primarily on the NatureServe data, but have also verified the accuracy of that data using the most up-to-data state heritage data available.  Please be advised that NatureServe data are not 100% accurate.  Where discrepancies occur, state heritage data override NatureServe data.