We arrive at an ending which is a beginning as well – the moment at which I ask what brought you to this page. Why are you exploring what someone might have to say about Florida’s Wildflowers? What, or who peaked your interest? How have you acquired the knowledge you’ve mastered, and what more would you hope to learn?
Those questions land us squarely on the topic of plant identification. As we learned from Confucius and other savants, everything begins with a good name. People depend on language to organize thoughts and communicate with others, and we need nouns, proper nouns as anchors. Entities (plants) require names – handles it’s said, tails to grab. Names and mental images tether the mind to whatever concepts we imagine, linking information that allows us to associate experience, to compare and contrast, to build stories that meld as personal understanding. Each person creates, or as Piaget would say, “constructs” a unique knowledge set, a multidimensional world view animated by associations, processes, and yes, prejudices. It’s those personal stories about Wildflowers and general Natural History that engage us, that make us “plant people” for whom plants are integral to how we understand and interact with the world in which we live.
Plant people are self-selected, innately curious about the green and growing life around them. That curiosity is stoked by knowing the identities and nature of plants in our paths. This is not a sensibility shared universally; many (most) people have other interests. After years of engaging with the general public at an active botanical garden, and decades of teaching botany in various situations, I came to the sobering conclusion that people in general do not find plants nearly as fascinating as I do. My best hope, in working with a new group of students, was to convey something about plants that explained my own enthusiasm, and perhaps to append a few solid bits of understanding to their own knowledge base. I took Piaget to heart. My goal is to help individuals build their own, scientifically-valid understanding of plants, regardless how rudimentary their starting place or how unexciting that may seem.
Encountering a new student inherently interested in learning more about plants is always a delight; I figure that’s one in a hundred people. Your being on this page suggests you are of that sort, one in a hundred. We share interest in plants, thus my assumption is that you are hoping to add some new bits of information or skill through our conversation. Getting right to the point, then, the basic lessons introduced below revolve around how one can identify an unknown plant and learn what others have discovered.
The easiest way, I believe, is to walk around with someone who already knows the plants in an area, to have the personal benefit of another person’s own trail of discovery. In fact, that’s a crucial step for most people I believe.
But there are other resources, brochures, guides, broadcast programming, books, manuals, journals, and digital media, each with its own approach and each more valuable to a particular audience.
Perhaps the most popular and readiliy available publication for Floridians would be Hammer’s Complete Guide to Florida Wildflowers, which pictures over 600 native wildflowers, providing brief but useful descriptions, along with some taxonomic history. That kind of guide is testimony to the importance of good identification. A good name is key to information through communication, on the shelf, or through the web.
Many people will have already discovered iNaturalist, and some of you might have purchased an identification app, like Picture This. Both have proven useful for me in differing circumstances. Picture This ($39.95 a year) is not so excellent with native wildflowers, but has proven reliable in identifying ornamental plants (especially tropicals) while visiting other countries. The iNaturalist application (which is free) is much better with native plants, and brings the bonus of assistance from other people who will respond with identifications and additional information. Both programs provide far broader capacities, if you are willing to train yourself in their functions.
In practically every webinar I’ve utilized and discussed information available through the Atlas of Florida Plants, a project that emerged around 1995 (under software leadership of Sean Landry), parallel to the Flora of Florida production, and has now been adopted by institutions in Alabama and New York. A good interface and database are quite an accomplishment, but the true functionality comes with data input. That has come through the on-going efforts of the Florida team (ISB, Institute for Systematic Botany), originating from the Wunderlin and Hansen program at the University of South Florida. Massive time and effort have gone into loading and verifying information and inputs of metadata. Moreover, work continues on the Atlas, as new information and capacities (such as inclusion of Keys) continue to emerge. If you have any interest in learning more about Florida’s flora, you have to become familiar with the Atlas.
Most recently (in February, 2025), Dr. Weakley and his team at University of North Carolina expanded their flora project to include a FloraQuest app specific to Florida. At a modest $19.95, you will really want to acquire this app. Yes, you can visit their site on-line, and examine the emerging flora, but the new app provides several unique capacities: 1. if space is available, you can download the images to your device (I recommend a tablet, such as an iPad), which means the app is totally-functional without internet connectivity; 2. you can adjust the “filter” such that keys include only plants reported from given areas of the state (it’s divided into 4 regions); 3. photographs are available for almost every species, which helps verify identifications; 4. each family and most genera are introduced with a brief explanation of important and particular characteristics; 5. terms include imbedded links that allow quick access to the glossary. FloraQuest is an excellent complement to the Atlas, but lacking links to herbarium specimens and distribution maps, the app doesn’t replicate the solid values of the Atlas website.
Learning about new plants, the task of seeking verifying an identification leads to a search for more complete descriptions, images, or even available herbarium specimens, which ends with more technical literature, floras and monographs, landing you inevitably to the construct called a “dichotomous key.” Below you see pages from the 2011 Guide that included the Key to species of Asclepias.
Botanists who describe and catalog plants have an obligation to outfit their publications with a set of diagnostic breadcrumbs to plant identities, outlined is Key, which is simply a “decision tree” presenting a series of choices based on observable characteristics. Like any maze, to walk you through their own observations.
Keys, Descriptions, and Synonymies (listings of other names published to represent the same plant) are core to plant taxonomy, reminding us that unlike contemporary experimental research, the descriptive nature of “Systematics” and the rules for nomenclature mean that botanists are historians also. Almost anything descriptive work ever published may have real meaning, even after three centuries.
That too reminds us that the purely descriptive task of today’s manuals and monographs follow patterns similar to earlier work. There are only so many characters that work for identification and they will be well-used. Below you see Linnaeus’s 1753 entry for Asclepias. I’ve framed the outline he superimposes on his catalog, a simple decision tree still relevant in modern works.
Linnaeus wasn’t unique among early botanists. On the left, below, we revisit Jussieu’s chart to major plant groups, while to the right are illustrations that pair with keys to identification Waller devised in 1689, attempting in vain to gain publication support from Britain’s Royal Society.
Though Waller clearly was inventing a Key to British herbs, Lamarck (1778) is given credit for the first publication of a fully-developed key to plants in a flora. His “analytical method” spans hundreds of pages over three volumes, documenting the decision tree that he believed would lead a reader to the proper identification of every plant (including fungi and mosses) found in France. On the right side, note Lamarck identifies two Asclepias species, Asclepias alba (with pale to white flowers) and Asclepias nigra (with dark flowers),
Returning to the present, we’ll examine treatments of Senega (historically Polygala) in Florida, beginning with the 2011 Wunderlin and Hansen Guide. In the following series of slides, I’ve framed the first and second pairs of couplets, the first set (framed in yellow) parses species out based on flower color, pulling out six easily-segregated plants.
The following set of couplets breaks leads based on inflorescence structure. All of the Senegas organize flowers in a raceme (a spike in which flowers are borne on pedicels, not sessile). Some species cluster the flowers in a “capitate” manner, cluster closely as in a pompom. Others spread flowers sparsely along a longer peduncle (the main stem of an inflorescence or flower). In the first green-framed couplet, you see the authors can segregate plants based on how those racemes are, or are not, clustered to form a compound “synflorescence.”
That is a straight-forward Key, exemplifying the way keys work, which is somewhat formalized. Below are teaching aides from Vascular Plant Systematics (1974) written for botanists in training. The first page covers basic procedures for constructing a key.
That’s followed by examples of two different, basic key formats – the Bracketed and the Yoked construct. The bracketed key is a bit easier to compose because you pair the couplets as you move through the basic choices. The yoked key is a bit easier to use, but requires attention to formatting, as well as a bit more space for layout. The nice thing about a yoked key is the way it keeps groups with shared characteristics together. In a purely digital Key, that graphic convenience is sacrificed.
The final slide in this sequence gives pointers as to how one can most effectively work through (botanists say “operate”) a Key. The authors focus solely on identification as the function of a Key, but there are many other useful aspects we will discuss later.
We return to the yoked Polygala Key from the Guide so as to compare that to the bracketed version you’ll find in the Plant Atlas (see the second slide below).
From this take-off point, we move to discussing how you might analyze a Key and what added benefit or understanding is to be gained from the effort. Here are some thoughts up front, followed by a sample of my spreadsheet based on the Atlas Key for Senega:
Three pairs of slides follow, each highlighting a decision sequence that walks you through the yellow Senegas (Polygalas). Senega cymosa and S, ramosa fall out as plants producing scapes that bear flat-topped clusters of bright yellow flowers in dense racemes. In our area, the two plants are commonly found near each other, S. cymosa, which is twice the height of S. ramosa, often occupies wetter sites. It’s unlikely you’ll observe the seed characters (pubescent in S. ramosa and glabrous in S. cymosa), but the wings (the larger pair of lateral sepals) of S. ramosa are conspicuously narrower, which gives the inflorescence a somewhat more open, sharper appearance. Inclusion of seed characters reminds us Keys are typically produced through examination of herbarium specimens using good optics. You’d need to catch just the right circumstances for that to be a useful field character, but it’s probably readily seen with a specimen and dissection scope. Characters such as this bolster the credibility of the distinction, and can be used by the well-prepared.
Examining the lead (green) that points to solitary racemes, we see additional imbedded couplets (beginning with the yellow pair). These two lead are awkward, an issue easily resolved by examining specimens, photos, and distribution data. The first pair, Senega nana and S. smallii are compact, ground-hugging, completely distinct in aspect from Senega lutea and S. rugelii, which are significantly more erect and open. In the Atlas, you can check out herbarium specimens, as well as photos.
But don’t fail to examine the distribution maps. There you’ll see that S. smallii is restricted to the very southern tip of the Peninsula, and S. rugelii is not found in the Panhandle. For people studying these plants in Northern Florida and the Panhandle, that really means you’ll likely encounter only the dwarf, green-yellow flowered Senega nana, or the loosely erect, orange to sometimes yell0w-flowered Senega lutea.
Going through this excercise is helpful, but unnecesary to arrive at a proper identification. However, if the goal is to flesh out your understanding of the different plants native to Florida, this compilation brings the most diagnostic characters into good focus.
For completeness, in the slides below I’m including the remaining segments of my spreadsheet from the Key in the Atlas. (Following that, we’ll step back to examine and compare the Key to Senega in FloraQuest.) Note the Atlas Key segregated Senega balduini based on its white perianths, but then quickly pulls this species out based on the branched inflorescence.
The segment shown in the slide above segregates plants with that will usually have basal leaves (highlighted in orange, leaves so closely spaced so as to appear whorled) from those that show only cauline leaves. In pink we see a character that will be repeated in the following set of leads – floral bracts deciduous versus persistent. It’s not such a simple character in that the bracts are not so conspicuous, and the distinction only works if you are examining specimens that have already shed many flowers.
Plants segregated as having alternating leaves can prove difficult also, though Senega incarnata falls out as very distinctive, as does Senega polygama. We’ll examine these distinctions in the next segment, when we follow the FloraQuest Key.
Starting again, examining the FloraQuest key to Senega, you can see the graphics are different. It’s an app, and the authors assume you are simply dedicated to identifying the plant, perhaps in the field (the app, including all of the photos, can be downloaded and used without connection to the internet!)
Up front, we see an incredibly useful note. FloraQuest introduces each family with an explanation of characters and terminology pertinent to the group. That is very helpful. Here we are reminded that each flower has one highly modified petal, the keel, which is partially united with the other two strap-like petals, as well as the 8 stamens. And, it’s explained that two of the five sepals, the “wings” are enlarged (bigger than the other sepals, and larger than the petals), forming the most conspicuous component of the flower in most species (S. incarnata being the standout).
Once in the key to Senega, you see the “couplets” are numbered, each showing how many species fall within that framework, and offering the option to move further along. The authors stress useful vegetative characteristics, and you’ll see this extends to introducing each lead with a difference based on foliage, which allows the Key to parse Senega balduini along with the yellow-flowered plants. I have concern about this vegetative character (which is used in every key to Senega), however. The most common of these plants in our area, Senega lutea, often shows no basal whorl; small plants spring right up into a short flowering specimen. Secondly, this group hardly calls attention to itself unless flowers are showing some color, so in the field the flower color is by far the easiest identifier. I prefer the somewhat more artifical couplet in the Florida Atlas, which breaks S. balduini out based on flower color, then segregates it based on the branched inflorescence.
But let’s not quibble with an app that brings astonishing new capacity to the field botanist. I really like to see the entire key, so I know where things are going, and you can do this with FloraQuest by selecting a button that will appear offering a view of all couplets (within the bracket you have selected.) In Senega, this is fine, though I found the Keys are much easier to operate on my iPad than through the small screen of my cell phone. Note any technical term is written in blue type, which means there is a link taking you to a definition, another really useful feature.
But in order to see the entire key, I entered the FloraQuest leads for Senega into a spreadsheet, just as I had the key from the Florida Atlas, which gave me to analyze the organization, as well as giving the ability to restructure the key as bracketed or yoked.
In the following slide you see the paired couplets, colored for easy comparison of leads within each couplet. (Note the Key numbers and treats subspecies and varieties as separate species.) It’s obvious the authors were hoping to present a natural key, i.e. one in which the plants fall out into groups reflecting their evolutionary affinities (recognized by Sections within the Genus).
One goal in using both the Atlas and the FloraQuest keys was making a better determination (identification) of two Senega populations I encountered recently in Apalachicola NF (Liberty County). These plants would key most likely to Senega chapmanii or S. mariana (and possibly S. nuttallii), with the most significant difference being whether or not the tiny basal bracts along the peduncle persist or abscise. That’s an awkward thing to interpret (especially in the field), since on every peduncle some lower bracts were present and others absent. Perhaps this develops more obviously in dried herbarium specimens. In the end, through permission of Austin Mast and with the assistance of grad student Benjamin Ajayi, I visited the FSU Herbarium, where there was a folder for each species with plenty of samples. There it became obvious botanists studying specimens had clued into a particular character of the inflorescence, pointed out in the Atlas key. Senega chapmanii forms new buds a bit above the main cluster of open flowers, creating something of a tapering point to the shape of the inflorescence, while S. mariana maintains a more rounded shape. That odd feature also shows in photos (see below), so it’s apparent in the field. Tentatively, then, I’m labelling this as S. chapmanii, hoping that with further field encounters I can find something corresponding to the other two species.
I did voucher (make a specimen of) each plant, such that I can make better future comparisons. Moreover, the voucher creates the option of some future botanist “annotating” the specimen with a more considered opinion.
Reflecting on the FloraQuest key, I found easy access to the flower photos to be wonderfully valuable. And I came to realize the FloraQuest app complements, but does not duplicate or replace the Florida Atlas. The app doesn’t provide distribution maps, and gives no access to herbarium specimens. It would be dynamite if FloraQuest could link you directly to entries in the Atlas, but that doesn’t require too many steps if you have internet access.
Stepping away from the Polygalaceae, I decided to investigate treatments of a more complex group and a widely-known genus – analyzing the Flora of Florida key to genera of Composites, and investigating both the Flora and FloraQuest keys to genus Helianthus.
The following slide shows the FloraQuest intro to Asteraceae, including more refined definitions for Composite terminologies.
Sometimes a natural group will fall out cleanly, as with the Chicorieae (Composites with fertile, all ligulate heads). But for Onopordum, all of the other genera are in Key 1.
The next image shows Index couplets from Flora of Florida that point to the five Keys to genera. Studying the key characters employed to direct the reader, several issues become apparent:
- the key is generally artificial, with only a few instances in which Tribes fall out as a tight group (Key 1, which is all Chicoreae, see below)
- there has to be repetition, some genera will be duplicated. Gaillardia appears 5 times, in three different keys (see below).
- key couplets are repeated when one character separates groups that are very similar otherwise.
The slide below shows the first page from the Asteraceae Key in Flora of Florida, as well as the spreadsheet for the couplets that lead to Helianthus and the introduction to genus.
Helianthus shows up in two solutions, once in Key 2 (Radiate heads), and once in Key 5 (discoid heads, based on the character of Helianthus radula alone). In the slide below, you see (in teal color) the Couplet Key History, which allows me to make a sort that generates a yoked key, but also tracks the leads that single out Helianthus. I’ve summarized the leads for each of the two sequences that take you to Helianthus, constructing a “diagnosis” encapsulating features that define the genus (the first overall, the second specifically relevant to H. radula), i.e.:
Below you see a second spreadheet, this laying out the Key to Helianthus in Flora of Florida.
In the three slides below I pasted distribution maps from the Florida Plant Atlas for each species of Helianthus native to the state. The first slide groups five species with very restricted distribution in Florida, reflecting the Southeastern extent of each species. Three others (to the right) show wider distribution, but also reflect plants with broader distribution outside the state.
Species with distributions shown below are (to the left) four Helianthus native to Florida with more general distributions and (to the right) two species that are only lower Coastal Plain, Helianthus floridanus and the endemic H. carnosus.
As a simple example of the usefulness of distribution maps when operating Keys, the following slide marks plants you’d be unlikely to encounter from Gainesville southward, simplifying the task of keying plants in that area.
If you are using the FloraQuest Florida app, you have the very useful option of limiting the “filter”, which is set by default to cover the entire state. Tap on that filter and you are given the option to turn of any of 4 regions, which will then adjust options to eliminate plants not reported in the remaining range. This, therefore, makes the Key regional, which is brilliant. You will note, however, that the graphics preserve the various steps that would normally be present, it’s just that those solutions are eliminated. Selecting only South Florida will still show the more complex couplets, but will lead you to a reduced slate of candidates – Helianthus radula, H. angustifolia, H. debilis….
In the slide below, I’ve summarized elements that define Helianthus in Florida, combining key characters used for identification with distribution and descriptive information.
Finally, the take-home lessons for me are that Keys, though published in floras primarily for identification, reflect summary points, diagnostic characters as defined by content specialists (people who have studied the group intensely). By studying and analyzing a Key, the beginner can advance quite rapidly his or her own understanding of a plant group. Below I’ve listed my thoughts about Keys, their construction, nature, utiity, and benefits:
Link to this Page: https://botanyincontext.com/knowing-keys-knowing-plants/