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New Databases Linked: Flora of North America & NatureServe Explorer

November 11th, 2022 by Alex Zorach

A little less than two years ago, we announced the linking of our plant articles with various other websites and plant databases. We are pleased to announce continued progress on this front, and we want to highlight the most recent two additions to our collection of links on each plant article: Flora of North America and NatureServe Explorer. This post will explain a little about each site and the ways in which each is most useful.

Flora of North America

Flora of North America (FNA) is a massive project to collect in a single reference the names, taxonomic relationships, distribution info, and morphological descriptions of all plants occurring in the wild in North America north of Mexico. The material is available both in print volumes, and on the web. Formerly, FNA was only available through the efloras.org website, which also hosts other floras including Flora of China, Flora of Missouri, and several others. However, recently FNA has moved to its own dedicated website, which is more readable, mobile-friendly, and slightly more feature-rich.

Our interlinking with FNA coincides roughly with FNA's dedicated website graduating from its "beta test" period, so we have linked only to the newer site.

FNA is only partly complete, but even in its incomplete form, it represents an unparalleled resource, especially for its description of the morphological characteristics of each plant, which are useful for performing rigorous plant identification. It is important to note, however, that FNA is a better resource for certain types of information than others. We have found its descriptions of morphology to be its best / most useful aspect.

FNA not only has records for species, but also for higher (families, subfamilies, genera, subgenera, sections, etc.) and lower (subspecies, varieties) taxa as well. Furthermore, at each level there are dichotomous keys that can allow you to rigorously work to narrow down an ID of a particular plant. If you are serious about plant ID you will likely benefit from using their site directly, not just following the links from our site, as it has a much richer structure and organization than is evident from our links alone.

Another particular strength is that FNA covers a larger area, so the information on plant morphology covers a larger range of natural variation that is often omitted in state or regional sources. As such, when used for rigorous ID, FNA's material remains applicable over a much larger area. Although regional sources can be easier to use to identify plants in their specific region, they often become inaccurate if used outside their scope.

Limitations or Shortcomings of FNA

In some cases, FNA also provides information on habitat; where this information is present it tends to be highly accurate, but the presence and/or depth of this information is inconsistent.

The information on plant ranges and distribution is mostly coarse, presented only at the level of states and provinces, occasionally supplemented by brief verbal descriptions, but nowhere near the level of detail of BONAP, USDA, or any of the regional resources we consult. There are also many plant populations, especially introductions, missed by FNA, so in general it tends to under-report plant ranges.

Arguably a more serious problem with FNA is that it often marks plants as native to regions where they most certainly are not native. There are multiple causes for these oversights. In some cases, FNA perpetuates the failure of USDA PLANTS and other earlier sources to distinguish between plants native to a continent, but introduced or expanding elsewhere. For example, FNA marks the prairie sunflower (Helianthus petiolaris) as native everywhere in North America, whereas it is has expanded its range or been introduced both east and northwest of its native range.

In other cases, the errors relate to sloppy or incorrect plant taxonomy; for example FNA does not distinguish between any subspecies of the common reed, Phragmites australis, and wrongly reports this as one species native to everywhere it is found in North America, when in reality most populations are introduced from Europe, and the native and introduced populations are considered by most authorities to belong at least to separate subspecies, and by many (including us) to be separate species, the Eurasian common reed (Phragmites australis) and American common reed (Phragmites americanus). The distinctions between these species/subspecies is particularly relevant as the introduced taxon, whether treated as a species or subspecies, is one of the most damaging invasive plants in North America, whereas the native one is endangered. Holding onto the older treatment in this case is particularly inexcusable, as their entry on the common reed has been updated as recently as 2021, while evidence for the separate populations was published in 2004.

For these reasons we recommend ignoring the information presented by FNA on range and plant's status in an area as native or introduced. We will update our recommendations if we see evidence that FNA has systematically addressed these deficiencies. We continue to find BONAP and regional sources such as the Maryland Biodiversity Project, Calflora, E-Flora BC, and various state and regional plant atlases to be the best sources to consult for assessing plant ranges and status in a region, and we recommend checking these sources if you want detailed information on exactly where a plant occurs, that goes beyond what you can find on our current-generation range maps.

FNA's presentation of plant taxonomy is inconsistent. In some cases, it provides exceptional clarity, giving detailed explanations of relationships that are often not clearly explained in most sources. However, in other cases it can be deficient in its treatment of taxonomic relationships, either by holding onto outdated treatments rejected by most modern authorities, or in some cases using a reasonable, up-to-date treatment but providing no explanation for potentially confusing relationships or changes in the taxon in question. On average, FNA is significantly slower to incorporate new information than Plants of the World Online (POWO), which we have found to have the best and most up-to-date information on plant names and taxonomy.

NatureServe Explorer

NatureServe Explorer (NSE) is an entirely different type of resource from FNA, with complementary strengths. The focus of NatureServe Explorer is on conservation.

Although many websites provide state- and province-level range maps, NSE stands out in that its maps are color-coded, often with additional verbal information, to denote the conservation status of a particular species in each region. This information is highly relevant because most species, even the most common ones, are locally-endangered somewhere, typically around the edges of their range. NSE maps also show where species have been locally extirpated.

The maps are only a small part of the resources provided by NSE. Although some articles are more complete than others, many of the plant pages on NSE have extensive verbal descriptions of the conservation issues relevant to the plant. This information often provides useful information both on the plant's habitat requirements, and the way these interact with human land use patterns and other potential threats to the plant's populations.

Lastly, in some cases, NSE provides explanation of taxonomic relationships, including discussion of historical changes, that can be hard to find elsewhere.

Limitations of NSE: Primarily Incompleteness

Like any resource, NSE has its limitations, and in this case, the largest issue is its incompleteness. In contrast with FNA, we have yet to find any major errors or misleading information on the site, but unfortunately NSE is less far along in its completion. A large portion of the maps on the site are incomplete, showing the ambiguous "no status rank" for large numbers of states and provinces. The finer spatial data using a hexagonal grid are available for even fewer species, and those with data usually only have it for a small part of the range.

In general, NSE's data are too incomplete to be a useful indicator of where the species occur. However, we have largely found the existing data to be accurate, especially when the written descriptions below are also consulted, as they often clarify various nuances.

Links Added To ID Guides

Because FNA is so useful for plant identification, we have added links to the FNA records for all ID/Comparison guides for which these records exist. In addition, we have displayed three other linked websites on these guides: Go Botany, which has a New England focus, Illinois Wildflowers, and Virginia Tech Dendrology Factsheets.

What is next?

Although we have interlinked the vast majority of records from both of these sites, there is still a lot of cleanup work to be done, notably, in the linking of records where the scientific names used by these sites differ from the names we use, as well as records where our treatment of taxa are merged or split relative to how they are treated on these sites. This work is much slower and more labor-intensive, and we have not even completed it for previously interlinked websites, including BONAP.

There are also numerous other databases and plant websites on our list to integrate with, and we hope to continue this work in the coming year.

And, of course, we have all the other work on our site, including new plant ID guides, new articles, and continual refinement and completion of more range maps.

All Range Maps 2nd Generation, Taxonomic Updates, & Fundraising Goal Met!

September 29th, 2022 by Alex Zorach

We have three items of progress and good news to announce! The first is that we have finally retired all of the first generation ERA-based range maps, in most cases replacing them with newer, better maps. The second is that along the way, we have also made some important taxonomic revisions.

Unrelated to these achievements, we also met our first fundraising goal, and as such, have taken down the fundraising banner for the time since putting it up. The banner will return closer to the end of the year when we start working towards our next goal, but in the meanwhile you can still donate using the donation links in the header or footer of our site.

All Maps Are Now 2nd-Generation Maps

A little over a year ago, we annouced our second generation range maps which represented a significant improvement over our first generation of maps which we published in August of 2019. We initially published the easiest of the maps to generate, but there were intiially still 1,137 of the old maps. Replacing these was more difficult, because the maps that needed to be constructed were ones where there were complexities or challenges, such as taxonomic changes, inconsistencies in data, or other uncertainty or roadblocks.

But we have finally finished this task! And, in the course of completing these maps, we have also cleaned up a lot of the data on the site, data used in the ecoregion-based plant lists and search that we launched this March. These lists and searches are now fully free of the deficiencies of the first-generation range data, which included overestimating the ranges of plants at the edges of their range, failing to distinguish when plants were native somewhere but not everywhere in North America, and in a few cases even marking things as native that were not.

Key Taxonomic Changes, Including Mergers & Splits

We have begun updating the taxonomy of many plants to reflect newer research. In most cases, our new treatments reflect that of Plants of the World Online (POWO), run by the Royal Botanical Gardens in Kew, as we have found POWO to have the best taxonomic backbone. However, there are some instances where we have deviated from POWO's treatment. These deviations include several instances of taxa that POWO treats as subspecies of a single species, where we have separated them into two species, only one of which is native to North America. Probably the four best-known species we have split in this way include:

• Phragmites australis (Cav.) Trin. ex Steud. was split into the Eurasian common reed (Phragmites australis) and American common reed (Phragmites americanus)
• Urtica dioica L. was split into (the Eurasian) great stinging nettle (Urtica dioica) and American stinging nettle (Urtica gracilis).
• Viburnum opulus L. was split into European cranberrybush (Viburnum opulus) and American cranberrybush (Viburnum trilobum).
• Rubus idaeus L. was split into European red raspberry (Rubus idaeus) and American red raspberry (Rubus strigosus).

We split each of these taxa for compelling ecological reasons, such as the fact that the split taxa, in each case, hybridize in the wild either not at all (with Urtica) or infrequently (such as with Phragmites) and less commonly than other taxa (such as Quercus or oaks) that are separated into species. The splits also have the added benefit of clarifying the species-level maps. BONAP's maps for species that include both introduced and native subspecies, such as their map for Rubus idaeus (which lumps native and introduced taxa together into one species) can be hard to read and can obscure information, such as failing to distinguish between where only native populations are found, vs. both native and introduced populations.

We also merged a large number of species, particularly those that were considered separate by the USDA but have been merged under both BONAP's and POWO's treatments. Some of the better-known of these species include:

• Mountain Silverbell, Halesia tetraptera L., was merged into Carolina silverbell (Halesia carolina).
• Vaccinium virgatum Aiton was merged into highbush blueberry (Vaccinium corymbosum).
• Pacific Dewberry, Rubus vitifolius Cham. & Schltdl. was merged into California blackberry (Rubus ursinus)

In addition to merges and splits we have carried out a number of more involved reclassifications, where a taxon was split up and different populations (varieties or subspecies of it) was assigned into various different species.

In almost all cases, we updated our maps to reflect the new classification schemes, but there were a few complex and difficult cases where we have struggled to build maps, and in these cases we took the old maps down. We also left a few placeholders or markers for taxa that have been reclassified in such a way that, although the taxon is still recognized, it is no longer thought to occur anywhere in North America. Users searching for the names of these taxa will then see a page explaining the change and pointing them to the names for the new taxa. The best-known example of such a change is perennial glasswort (Salicornia perennis), whose page explains the changes fully.

These explanations can be found in the Taxonomy Notes field, which can be found at the top of each article, above the table of contents. We placed the field here because we thought it critical that a person know what exactly the article is referring to before reading the article or otherwise using it as a reference.

More Range Maps Verified for All of North America (Including Canada & Mexico)

In June we announced the verification of 3,272 range maps for all of North America; we have completed the next phase of these range maps, and now have 4,793 maps verified. What this means is that the maps have been completed for all of North America, including Mexico and Canada. Most of these are plants that only occur in the lower 48 US states, but it now includes 90 range maps extending into ecoregions that do not intersect the lower 48 states, mostly in Canada but a few also extending into Mexico, and many more plants whose ranges extend outside the US but only in ecoregions also intersecting the lower 48.

Presently, just under 30% of the 16,376 range maps have been verified in this way. Completing this process is important for us to be able to generate exhaustive plant lists for ecoregions outside of the lower 48 US states, which includes Canada, Alaska, and Mexico. We will likely prioritize Canada first, and prioritize completing these lists for ecoregions closer to the US, especially those in high-population areas as this is where there is the most demand for such lists, but we are also prioritizing common and ecologically-important species.

Our First Fundraising Goal Met

We have not only met but exceeded our short-term fundraising goal, the modest goal of $5,000. However, this is only the beginning of a multi-step process towards building a sustaining organization that will help us realize the full vision for bplant.org; we are still far from paying a single person a living wage for working full-time on the site, and even farther from being able to hire a staff to do even more. At the same time, meeting our first goal is encouraging; we have taken down our fundraising banner in the site's header for the time being, and will put it up some time closer to the end of the year when we set another short-term goal.

The donation links remain in the header and footer if you want to donate even before the banner reappears!

Thank you so much to all of the people who supported us financially and helped us meet our goals. And thank you also to all the people who have been visiting our site, reading our articles, and sharing and engaging with them on social media. We hope that you keep up both the support, and keep using and appreciating the resource that we are creating!

More Range Map Improvements, POWO Interlinking, And Notes Fields

June 7th, 2022 by Alex Zorach

This Februrary we announced a major improvement in our plant range maps.

Since that update, we have continued to build more maps, and additionally we have refined, expanded, and verified a larger portion of the maps.

As of today, a total of 3,272 maps have been verified to be complete for the entirety of North America. This mostly includes species that occur only in the lower 48 US states, but it includes some species where we have actually built the portion of its range map in Canada, and a few in Mexico.

We have also cleaned up our database, deleting and merging duplicate records, and have reduced the number of plants listed to 20,580.

POWO Interlinking

We have begun the major project of interlinking our site with Plants of the World Online (POWO). POWO is run by the Royal Botanical Gardens in Kew, London, and is primarily a database of plant names using a taxonomic backbone, the International Plant Name Index (IPNI), that is the most up-to-date and comprehensive that we have been able to find. In some cases, POWO also has information on plant distribution and native vs. introduced status in various regions.

The process of interlinking our site with POWO is slow and complex, because in many cases, the taxa they recognize and the names they use to refer to them do not correspond in a one-to-one way to the taxa recognized by USDA, BONAP, and other sources. These discrepancies mostly reflect POWO being more up-to-date on the latest taxonomic reclassifications, and they also reflect the correction of errors and inconsistencies in the citing of names, some of which have propagated for hundreds of years.

We have currently linked up 3,032 records on our site with POWO, which represents about 14.7% or a little more than 1/7th of the records. Our goal is to interlink all records.

Why does plant taxonomy matter?

Taxonomy is the branch of science concerned with classifying and naming living organisms. Plant taxonomy is a messy subject, with plants frequently being reclassified and renamed, species split or merged, moved into different genera, or reclassified between proper species and varieties or suspecies. Although at times, plant taxonomy can seem like splitting hairs, it has real-world implications for conservation and ecological restoration work.

The biological species concept centers around whether or not organisms from different groups can interbreed and produce fertile offspring. Although there are many complexities and nuances, the basic idea is that plants of the same species can freely interbreed, whereas ones belonging to separate species either cannot produce fertile offspring at all, or can only do so rarely or with difficulty.

More up-to-date knowledge about which populations of plants constitute separate species and which do not is important both for conservation of native plant species, and monitoring of introduced species that may have risk of becoming invasive. Interbreeding can introduce new genetic material into small, isolated local populations of plants, giving them greater ability to adapt to threats and changing conditions. Similarly, interbreeding can increase the risk that introduced species will develop greater vigor and become invasive. And whether or not a local, morphologically-distinct population represents its own, possibly endangered species with unique genetics, vs. a quirky manifestation of an abundant species that is not threatened, can also help conservationists prioritize which populations to protect.

We hope that by keeping our taxonomic backbone more up-to-date we can ultimately help inform conservation and ecological restoration work, both with respect to protecting native species and keeping an eye on introduced species that have established in the wild and may pose a risk of becoming invasive at some point in the future.

New Notes Fields

Our plant articles have always had a "Notes" section, which is somewhat of a "catch-all" category for information that doesn't fit into any of the other sections. Recently, we created two new places on an article where such supplemental comments could be found: range map notes and taxonomy (classification) notes.

Range Map Notes

Although we have made the best effort to make our range maps self-explanatory, they communicate a lot and there are many cases where there is additional information relevant to a plant's range, distribution, and status (i.e. native, introduced, expanded, etc.) in particular regions, that cannot be fully or easily communicated in a map.

In these cases, we have added verbal comments under the map. Some of the reasons you may find comments include:

• When there is a major discrepancy in ranges reported by different sources, such as USDA, BONAP, POWO, or various regional flora or plant atlases. In these cases we often explain the discrepancy and note which source(s) we have favored in our map.


• When we needed to make a difficult judgment call between marking a plant Introduced and Expanded, we give the rationale behind our choice.


• In some cases (we have not exhaustively written such comments), we have added notes explaining that the range of certain plants extends into Canada and/or Mexico, but that we have not yet built this portion of their range map. In these cases we note whether or not the plant is native to these regions.


• In some cases we add verbal notes for species whose range extends outside the scope of our site, such as species found in Florida and also in Cuba, or ones found in Canada that extend around the Arctic into Greenland, Siberia, or beyond.

If you notice any maps that look confusing, possibly erroneous, raise questions, or just ones that might benefit from clarification, please don't hesitate to get into contact with us. We are eager to add additional notes anyhwere it will be helpful!

Taxonomy Notes

Largely in response to our interlinking with POWO, we have added a field for notes on the classification or naming of each plant. This field is above the table-of-contents for each article, just after the listing of scientific and common names and any synonyms.

Some of the things you may find in this field include:

• When a species has been split or merged in the classification scheme used on POWO, but this change is not reflected in the scheme used by USDA and/or BONAP, and we have not yet reviewed and/or incorporated the merge or split.


• When we see evidence, such as discrepancies in reported range maps, that there may be an inconsistency in the population(s) referred to by a name on POWO, and the way we use the name on our site and/or the way it is used in most US-based sources such as USDA, BONAP, and the various regional flora, but we have yet to figure out what exactly the difference is.


• When there is an error that is widely propagated, the notes field not only explains the proper relationships but give the readers a heads-up about inconsistent and/or incorrect usage in other sources so that the reader can properly interpret sources that may be using erroneous names. An example is the name Rubus tomentosus Borkh., which the USDA, BONAP, and many derived sources use in error to refer to a taxon that is best described as Rubus aetnicus Cupani ex Weston, when the original publication by Borkh. listed R. tomentosus as a synonym of black raspberry (Rubus occidentalis).

In most cases, you won't need this field. However, the hope is that in those cases where different sources are using different names to refer to the same plant populations, or use the same name to refer to different ones, and the situation is not as simple as connecting one or more synonyms, this field will help clarify things.

Other Progress

In addition, we have continued working on and publishing new articles. One of our most recent publications was a series of ID guides comparing the five members of the tricky Sanicula genus (Sanicle or Blacksnakeroot) that are found in the eastern US. We have published a total of six ID guides to help you tell apart the members of this often-neglected genus:

• Canadian Blacksnakeroot (Sanicula canadensis) vs Clustered Blacksnakeroot (Sanicula odorata)


• Canadian Blacksnakeroot (Sanicula canadensis) vs Maryland Sanicle (Sanicula marilandica)


• Canadian Blacksnakeroot (Sanicula canadensis) vs Largefruit Blacksnakeroot (Sanicula trifoliata)


• Canadian Blacksnakeroot (Sanicula canadensis) vs Small's Blacksnakeroot (Sanicula smallii)


• Maryland Sanicle (Sanicula marilandica) vs Clustered Blacksnakeroot (Sanicula odorata)


• Clustered Blacksnakeroot (Sanicula odorata) vs Small's Blacksnakeroot (Sanicula smallii)

In addition we published a new article on bloodroot (Sanguinaria canadensis), continued work on dozens of unpublished articles, and made numerous small tweaks to already-published articles as well.

What's next?

As usual, you can expect to see more continuing progress towards our various goals. In the short-term this will mean verifying a greater portion of our maps and constructing more maps into Canada, interlinking more records with POWO, and continuing the other work on our site like publishing of articles and ID guides.

In the longer-term we are planning more improvements to our presentation of taxonomic changes, and to review more of the merges and splits where POWO differs from our other sources.