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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.
Blackberries (Rubus subgenus of the Rubus genus) are a group that have experienced frequent reclassifications. Photo © lapemis, Public Domain, Source.

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.
This screenshot shows the location of the new range map notes (highlighted pink), as viewed on a desktop browser. In an actual article, the notes are not highlighted.

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:

Can you tell which Sanicula species this is, using our guides? The photo is from June 28th in Manitoba, Canada, north of highway 44, northwest of White Shell. The northerly location is itself a hint! Photo © Mary Krieger, CC BY 4.0, Source.

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.

Ecoregion-Based Plant Lists and Search

March 30th, 2022 by Alex Zorach

We have published plant lists for particular ecoregions, and related to these lists, added the ability to search for plants within a specific region and see their establishment means (i.e. Native, Introduced, Expanded, etc.) in that region in searches.

This is super exciting as it was one of the original goals of bplant.org, and has been years in the making. This post highlights where to find these new features, and how to interpret them and best put them to use. It also explains some of the background work that went into building the lists, including recent progress since our last blog post, and lastly, outlines future improvements and features underway.

Where to Find The Lists and Search

The lists currently are only available for Level 3 ecoregions. You can find these lists from a new "Plants" section listed on each of these region's pages. For convenience, we also linked to the lists for the Level 3 regions on all of the Level 4 subregions, accompanied by a message explaining that we do not yet have the lists for the regions with a finer level of detail.

How to Get to These Ecoregion Pages

There are many ways to reach the page for a region. If you want to look up a region at a particular point on a map, you can use our ecoregion locator which is linked to from the footer of every page on our site. You can also browse our state ecoregion maps to see the entirety of the ecoregions in each state. Alternatively, you can explore the whole hierarchy of regions from the Regions tab at the top of our site. Once you are on the page for a Level 3 or 4 region that intersects the continental US, you will see the new "Plants" tab.
Cropped screenshot of Ozark Highlands region pageThis screenshot shows the new tab visible on the pages for Level 3 and 4 ecoregions in the continental US, which takes you to the new plant lists and search.

Some of the Level 3 regions extend outside the continental U.S., and some of them are completely located outside this region, including in Canada, Alaska, and Mexico. As we have not yet comprehensively built plant range maps into these regions, we do not yet have the data to generate plant lists for these regions.

For regions that are entirely outside the continental US, there are no lists yet. For regions that span part of the continental US but also have significant areas outside of them, we have published lists but with a warning that they are incomplete.
This screenshot shows the new Plants section of the region page, linking to plant lists and also allowing an in-region search. Regions intersecting, but also extending outside the continental US, display this warning.

In-Region Search and Improvements to Search

The in-region search has an exciting new feature, made possible by the fact that you are searching within a specific region: the notation of the plant's status in the region, in the search itself. For example, the following screenshot shows a search for "Magnolia" in the Northern Piedmont. The entries in the "Map" column are color-coded to show the plant's status in the region.
An illustration of the new in-region search with a legend explaining the color codes.

Note that there are now two separate pieces of information communicated in the Map column: both the completeness of the map (with the gray stripes through tentative maps that have not yet been completed for the entirety of North America) and the establishment means for the particular plant in the region. There is a legend at the end of the search, denoting what each color means.

Updates That Made The Lists Possible

Probably the most important progress reflected in these lists is a massive cleaning of the data on the presence/absence, and establishment means (i.e. native, introduced, or expanded) of each plant in each ecoregion.

We have also been cleaning up our data on the plants themselves, which includes things such as merging duplicate records (including taxa that have merged due to reclassification), correcting missing and/or erroneous data, and correcting mis-linked data and linking more records to other databases such as USDA PLANTS and BONAP. We have reduced the number of plants in our database to a more manageable 20,579, and may reduce it further as there are still some duplicates and otherwise problematic entries. Both as a result of cleaning out the entries, and completing more maps, a much greater portion of the listed plants now have range maps, and the portion verified for the entirety of North America is also increasing.

How To Use These Lists and Search Results

Keep in mind that, although our level 3 ecoregions are, on average, smaller than most US states, and they do a much better job of corresponding to plant distributions, they are still a coarse instrument. If we mark a plant as present in a region, it means only that it occurs in the wild somewhere in that region; it is not necessarily common (or even present) in all parts of the region. In many cases, such as where plants reach their range limits in a region, plants may only occur in a small portion of each region. This is particularly common for regions that span a long distance.
The Sonoran Basin and Range extends from southeast California and much of Arizona well into Mexico, in Baja California and Sonora. Many plants found in this region are only found in a small portion of it. For example, the Saguaro (Carnegiea gigantea) is only found at low elevations, and even there does not extend into Baja California. Public Domain photo by US Bureau of Land Management, Source.

These lists and searches are thus best used only as a starting point and/or an instrument to narrow down your consideration of certain plants. If you are considering choice of plants for an ecological restoration project or garden, you will still need to do additional work to determine the plant's range and status in your area, on a finer-tuned level.

To this end we recommend checking the BONAP and/or USDA PLANTS county-level range maps (When both exist, BONAP is usually more accurate), which we have linked to from the "Links" section in each article, for convenience. You may also want to use regional sources, such as Calflora, the Maryland Plant Atlas, or whatever other state and regional resources are suitable for your area.

If our article on a particular plant is complete, you may also find information about its distribution either in notes written under the range map itself, or in the "Habitat" section, which leads into our next consideration. Check the links section to see what is listed; there may even already be some links to other regional resources. Even if a plant occurs broadly in your region, it will only occur in certain habitats.

Future Improvements

The current state of our plant lists is only a beginning. In the future we aim to add a number of features, including:
  • Expanding our data to include ecoregions outside the continental US
  • Adding higher levels of detail, such as level 4 ecoregions
  • Allowing generation of lists and searches for lower levels of details or aggregate regions, such as the level 1 or 2 ecoregions.
  • The filtering of plants by various characteristics, including taxonomy (such as plant families or other broad groupings), a plant's growth habit or form (i.e. Tree / Shrub / Perennial / Biennial / Annual / etc.) or habitat preferences (i.e. wetland/upland or moisture preferences, sun/lighting conditions, soil types, etc).
  • The display of establishment means (Native/Introduced/Expanded/etc.) on general searches, for those plants that have a single status type in the entirety of North America.
Some of these changes will likely come sooner than others. We are already well on our way to expanding plant range maps outside the continental US, and the lists for aggregate regions (level 1 or 2 ecoregions) will likely require less work than some of the other features.

Until then, please enjoy what we have already published!

Progress Updates on Range Maps and More

February 10th, 2022 by Alex Zorach

This past July, we announced the completion and publishing of 15,232 new range maps which brought numerous improvements on the previous 5,660 range maps we had published (based on the Ecoregional Revegetation Application or ERA.) At that point in time, we still had well over 1,200 of the old ERA maps that had numerous serious problems, including over-estimating plant ranges around the edges, and marking many species uniformly native that were not actually native in all parts of the continent. See our August 2019 post for a full explanation of the limitations of the ERA maps.
Here is the old range map for smooth oxeye (Heliopsis helianthoides) on the left, and the new one on the right. The new map offers multiple improvements, noting how this species is expanding its range (blue) into New England, where it is not truly native. The edges of the range have been reduced, particularly in the west where they were overestimated on the original maps; pale green denotes where the plant may or may not be found. The background color has also been darkened to make state boundaries clearer.

Since then, we have had numerous breakthroughs in the construction of range maps, and in other related aspects of our site. We developed frameworks for matching records in different databases and websites in the cases where the same taxon of plant (which could be a species, subspecies, variety, or other taxon) is referred to by different names. These improvements are an outgrowth of our interlinking with different plant databases that began in late 2020, and, besides facilitating range map construction, have also resulted in more thorough interlinking so that our plant pages now link to more external pages. We have also merged a few duplicate records and cleaned up various inconsistencies.

We have now published 16,277 of the improved maps. Of these, 307 have been verified to be accurate to level 3 ecoregions in all of North America (including Canada, Mexico, and Alaska.) The remainder of the maps are verified within the continental US only. Only 123 of the problematic ERA maps remain, and we are working rapidly to replace these. In the near future, we may simply take down the remaining ERA maps so as to reduce the amount of misinformation on our site. We have also been expanding the numbers of total maps, covering both native and non-native species that were not included in the ERA.

Sorting Out Reclassified Plant Taxa

One of the barriers to building our range maps, and to our research in general, has been the fact that numerous plant taxa have been reclassified, sometimes multiple times and in complex ways. What this means is that when we consult different sources, these sources do not always refer to the same plant populations by the same names. Not only are the same taxa referred to by different names in different sources, but different sources also group different populations in different ways, so that there is not always a clean one-to-one correspondence between the list of species or subspecies considered in one source, and those in another.
The Oenothera genus, evening-primroses, and related genera, have experienced a lot of taxonomic flux. Pictured here is Oenothera caespitosa Nutt., which is sometimes spelled Oenothera cespitosa. However, the proposed variety Oenothera cespitosa var. psammophila (A.Nelson & J.F.Macbr.) Munz. is now considered by most authorities to be its own species, Oenothera psammophila. Many taxa have had multiple varieties or subspecies spun off into separate species in such a manner; sometimes they are treated as new species, other times merged into existing species. The relationships between different classification systems can thus become highly complex. Public Domain photo by Patrick Alexander, Source.

In order to resolve these issues, we have begun adding additional features to our site. Many of these features are public-facing and will help you to know what is going on in the case of taxa that have been reclassified.

Authorities for Scientific Names

In keeping with common practice in plant taxonomy (and science in general), we now list an abbreviated authority next to the scientific name of each plant. These authorities represent the author that published the description of the type specimen for that species and named it, and in some cases, the author(s) that renamed them, in the cases that the type specimen was reclassified. You will see these authorities in searches, written in lighter gray text to de-emphasize them, as well as on the page for each plant.
Authorities are now listed after scientific names both during searches and on plant articles. Pictured here is the search for "Acer", the genus of maples.

Although in most cases referencing such authorities is not necessary, and in others, it is not sufficient for resolving ambiguity, there are some cases where checking the authorities can help to know what a particular name is referring to. Because it is "better than nothing", we have included this extra information in order to make our site more useful when referring to groups of plants that have been reclassified.

"Synonyms" of Scientific Names

As we record information about taxa that have been reclassified, we add scientific names to our site that are listed as "synonyms", typically in authorities like Plants of The World Online (POWO) and the closely-related International Plant Name Index (IPNI), and Tropicos. Thus, if you type in a scientific name that now points to a different species, the species it points to will show up in your search. For example, if you type in "Oligoneuron album" in the search, it will return a record for "Solidago ptarmicoides (Torr. & A.Gray) B.Boivin", and on the page for that plant it will list "Oligoneuron album (Nutt.) G.L. Nesom." under "Also classified as...":
This screenshot shows the page for a plant, prairie goldenrod (Solidago ptarmicoides), that has been reclassified, with the old synomym listed. Also note the authority both after the (new) accepted name and after the synonym.

These "synonyms" do not always represent one-to-one relationships. In taxonomy, what is considered a "synonym" is not a true synonym in the common sense of the word, and as such, it is perhaps a poor and misleading choice of technical language. Rather, a taxonomic authority will group together different scientific name + author combinations, which refer to different type specimens that the authority considers to be part of the same taxon. The name for the oldest type specimen is accepted as the name for the taxon, and others are listed as "synonyms".

However, other authorities may group taxa differently, and in general, authorities do not agree about which names are "synonyms" of each other. Even when they do agree, they may have different criteria that they use to classify individuals or populations other than the type specimens. Therefore the different names listed as "synonyms" do not necessarily refer to the same populations of plants when you see them written in external sources. This lack of correspondence can be confusing and can severely hinder one's ability to synthesize information from different sources.

We have not exhaustively listed these "synonyms" of each plant. For the time being, we have focused on plants where there are disagreements or inconsistencies between the sources we most frequently cite and link to, and have tried to list most names that are in widespread use. If you want a more comprehensive list of plant synonyms, we recommend looking at POWO, ITIS, or Tropicos. However, we warn you that these sites do not provide any clarification of relationships, and thus may have limited usefulness for resolving some of the tougher questions.

Future Plans for Handling "Synonyms"

Because the naming authority alone is not sufficient to unambiguously define what a name is referring to, in the long-run, we are working to implement a more rigorous system inspired by the notation Alan Weakley uses in his Flora of the Southeastern United States. We also hope to implement a system such as that proposed in this 2005 paper to facilitate data integration. These systems are currently in their early stages; we will write about them in a future post. We hope, however, that when they are implemented, they will greatly clarify the relationships between the different scientific names in the cases of reclassified and/or disputed taxa.

Donations & Financial Statement

Our 2021 financial statement is up; you can find it on our finances page, which you can always find in the footer of our site.

We are pleased to announce that in 2021, both our number of donors and our total amount of donations more than doubled. In addition, our percentage of donations spent on payment processing fees decreased slightly.

However, we failed to meet our $5000 end-of-year fundraising goal. For this reason, we are leaving our fundraising banner up on the header of our site, and will leave it up until this goal is met. Once it is met, the banner will not reappear until November. Thank you to everyone who has donated! We actually have received a flurry of donations in the new year, and are much closer to meeting our goal than we were at the year's end.

Plant Lists Are Coming Soon!

We have a number of exciting developments that we hope to complete within the next few months. One of the biggest of them is the publishing of plant lists for each (level 3) ecoregion in the continental U.S. This will allow users to generate lists of locally-native plants.

In order to generate accurate lists, we need to ensure that our data on these regions is reliable. The integrity of this data is currently the limiting factor preventing us from generating these lists. As soon as the remainder of the ERA maps are either replaced with our improved maps, or retired, it will likely be a short period of time, possibly a few weeks, before we publish these lists.

As a limiting factor in building the remaining maps is the resolving of difficult taxonomic relationships, we may end up building, at least partially, the tools discussed above to clarify the complex relationships between taxonomic "synonyms", as a stepping stone on our way towards the publishing of plant lists. And as we do this, it will become easier to link more of our plant articles to more external resources. So you can expect to see a lot of different incremental improvements to our site happening in the coming months, and it is possible that you may see some of the more "advanced" features such as clarification of relationships between different names for the same taxon, before plant lists are released!