Identifying Wildflowers, Part Four: Getting Technical


the flower, flopped over, which they seem to do a lot

Krigia species

Say you’ve narrowed an ID down to the genus, but just can’t figure out which species you have. To be absolutely sure, you probably need to consult a flora, but if you’re like me, you’ll be spending most of your time looking up the jargon, only to realize you don’t have the info you need anyway.

Take this plant, for example. For three years now I’ve been keeping an eye on a small patch near the C&O Canal towpath. I’m absolutely positive that it’s a Krigia species. But which one, Krigia virginica or Krigia dandelion?

After going through the process described in the past three posts, I still couldn’t figure it out. So I posted a few pictures and asked the question on the MNPS discussion page on facebook. One member helpfully pointed me to Weakley’s Flora of the Southern and Mid-Atlantic States.  In the Asteraceae key (page 1,145) was this:

“Pappus of 5 scales and 5 bristles; plant a winter annual; stem leafless or leafy at the base only…..K. virginica

…Pappus of 15-40 scales and 15-40 bristles; plant a perennial; stem leafless, leafy at the base only, or with many leaves extending up the stem. [go to 4]

…4 Stems leafless, the peduncles terminal; perennial from ovoid tubers, with long slender stolons which form new plants or tubers; pappus bristles (5.0-) 5.3-7.7 (-10.0) mm long…..K. dandelion”

OK, then. First, what is a “pappus”? It’s the tuft of hairs on seeds of plants in the aster family.

And right away I’m stumped again. I’ve never seen the seeds. It’s not like I visit this patch every day! If this ridiculous rainy weather ever clears up I’ll try going out there again, and hopefully the plants will have developed seeds, and hopefully those seeds won’t have blown away yet. [update: the day after writing this, I went back; 3 flowers, one fading, but none gone to seed yet]


the bud

But there are other clues in this flora. Are the plants perennials or winter annuals? I don’t know. I’m going to have to observe them closely over the season to determine that. I have reason to believe they’re perennial, but I’m not sure. If they are, they’re K. dandelion.

Next clue: the description of the stem. Not useful, since the stems of both species can be leafless. What I’ve seen in all the patch is a basal rosette of leaves and a single leafless flowering stem per plant. I’ve never seen leaves on the stem.


the flowering stem

Next clue: “…with long slender stolons which form new plants…” Well, it’s a patch of plants. Is it a patch from annuals that re-seed every year? From my gardening experience, I doubt it. These seeds will be wind-dispersed; if the plants were reseeding annuals, I’d see them scattered over a large area. What I’m seeing is a very tight cluster of plants growing close together, which suggests (but does not prove) stolons.

Next clue: “ovoid tubers”. Here’s a bit of info that I just can’t get. First, these plants are on National Parks land, where digging is forbidden (and rightly so). And second, K. dandelion is an endangered species in Maryland, ranked S1 (“typically 5 or fewer estimated occurrences or very few remaining individuals or acres in the State”). Even if it were legal, there’s no way I would dig up an S1/endangered plant! But seeing the roots would certainly solve the mystery.


the basal rosette

So still no answer. But, there’s nothing like the word of an expert. Fellow MNPS member Joe Metzger, who’s been doing this for forty some years, wrote:

“Notice the fact that there is a single large flower. Dwarf Dandelion (Krigia virginica) would have a cluster of flowering stems, each with a flower. This is an adaptation common in many annuals to insure seed is produced. Yours has only one flower and no indication of any others. The basal leaves in your photo are strap shaped and either entire or shortly dentate which is another good indication that is Potato Dandelion (Krigia dandelion). On Dwarf Dandelion they would rarely ever be entire and they are deeply dentate or serrate and not usually strap shaped, usually tapering at each end.”

So there it is. Not definitive proof, but the available information strongly suggests that this is Krigia dandelion (potato dwarf dandelion), a Maryland endangered species.


Identifying Wildflowers, Part Three: Names Change; Location Matters


Scutellaria nervosa, because this post need a photo and I really like this one

There have been many systems of plant classification over the centuries, but until recently most were based on flower and fruit morphology. Starting in the late 1990s, the Angiosperm Phylogeny Group set out to devise a better system, one based on DNA analysis and phylogenetic (evolutionary history) studies. They’ve since published four systems, the most recent one this year.

As a result, some of the species in the guidebooks I mentioned in part one of this post – especially Newcomb’s – no longer exist. Not that the plants have become extinct, but they’ve been renamed. Sometimes two or three different species have been combined into one. Sometimes species have been moved into new genera, or even new families. (See this post from last October: Are Asters Really Asters?)

This makes using the internet problematic. If I’ve gotten a tentative ID from the books, the next thing I do is google the species name. If the search turns up a different name, then I know there’s been a change. For example, a google search of Sanicula gregaria yields 5 hits for Sanicula gregaria and five for Sanicula odorata on the first page, which is a clue. When this happens, I turn to ITIS (the Integrated Taxonomy Information System) to find the latest name; in this case S. gregaria is now called S. odorata. But I’ll search under both names for the information I want, since some sites don’t update frequently.

Once I have that sorted out, there’s another thing I want to check before saying for sure which species it is. As the real estate agents like to say, location, location, location. The guide books will say where a plant is found, but they can be vague, especially if you found the plant at one extreme of its range.

The USDA PLANTS Database is a good resource for taxonomic, conservation, and location information, but with a few caveats. First, they often use older botanical names (though this seems to be changing). Second, for Maryland many species are shown as present in the state, but there’s no data at the county level. Look at the page for S. odorata, for example; you’ll see dark green indicating where the plant can be found. But if you zoom in, you’ll see the whole state of Maryland is light green, indicating that there is no county data. So where in Maryland has it been recorded?

The state of Maryland has many different habitats, and plants that grow happily on the Eastern Shore probably won’t be found on the Appalachian Plateau, so having more specific location information is important.

Another good resource, better for this purpose, is the Biota of North America Program’s North American Plant Atlas, where you can see county level maps for each genus. Looking at the page for Sanicula, you can see tell quickly that four species are present in Maryland. Click on each map, and you can see that S. canadensis is present in most counties, S. marilandica is present in nine counties but rare, S. odorata is present mostly in the Piedmont counties (and some in the far west and some on the Eastern Shore), and S. trifoliata is present in only a few counties, and rare. If the plant in question was found in Howard County, I can say that it’s is unlikely to be S. marilandica.

A third resource is the ever-growing Maryland Biodiversity Project, which is adding new records by the dozens every day. I can’t say that it’s the final word, because absence of records does not equate to absence of a plant (it’s a work in progress.) From the home page, pull down the Plants menu, click on Browse by family, choose Apiaceae, then click on the word Sanicula in the Genus column, then click on each species to see a map of where they’ve been recorded, and usually photos.

(As an aside, I’ll going to brag a little: the MBP has only three photos for Scutellaria nervosa, and they’re mine.)

Once I’ve determined that a species does indeed grow where I’ve found it, I’ll go to Illinois Wildflowers for a detailed but not too technical description. Another good site is the New England Wildflower Society’s gobotany, which offers dichotomous keys and rather technical descriptions. Of course many Maryland natives aren’t found in Illinois or New England, but a lot are.

If I can’t narrow my search down any further, then I probably don’t have the right information. But there are other places where I can dig deep. More on that tomorrow.

Identifying Wildflowers, Part Two: Observing the Plants


How do I know it’s perfoliate bellwort and not large-flowered bellwort? The bumps inside the petals are one clue.

In yesterday’s post I mentioned that color isn’t the most reliable of characteristics. There are a few other things to beware of. First, matching by pictures doesn’t work as well as you may expect. It will often get you to the right genus, but not always to the species. Second, the guidebooks describe ideals, but plants don’t always grow in ideal conditions. Environmental conditions and stresses can change how a plant looks. Be aware that petals can be missing, especially as a plant nears the end of its blooming period. I’ve found variations in leaf shapes, and one author’s “dentate” might be another author’s “serrate” – and how much of a difference is there between the two terms, anyway?

To identify a flower you need to observe the whole plant. Closely.

trout lily with Dentaria foliage

what flower is this? (hint: the foliage is from a different species altogether)

This might mean carefully moving other foliage out of the way. A good first step: check that the plant isn’t surrounded by poison ivy or stinging nettles, or that some critter isn’t hiding under or near it. Use a stick rather than sticking your hands in.

It’s best to have a book at hand when you do this. If you don’t, take lots of notes. Measure things when you can. I carry a 3′ tape measure, but you can estimate using what’s on hand, like “one and a half pen lengths”, then measure your pen when you get home. In my experience identifying later from photos is dodgy; often the pictures are missing a critical detail, no matter how thorough I thought I was. For that matter, I usually miss something when taking notes, so again, having a book at hand is best.

What to observe – and this is only a partial list:

The flowers: number of petals, how they’re arranged, their symmetry (bilateral or radial), color, presence or absence of floral scent, size.


a violet: bilateral symmetry (irregular shape if you’re using Newcomb’s)

How the flowers are borne: singly or in groups? At the end of the stem or along the stem? Coming from the same node as the leaves or not? Are the flowers on little stems (pedicels) or are the flower bases against the main plant stem?


Venus’ looking glass: flowers in the leaf axils


trout lily: a single flower atop a leafless stem, two basal leaves


long tube valerian: a terminal cluster of flowers










Are the flowers are on the same stem as the leaves, or on a separate stem?

The whole plant: height, branching, arrangement of leaves (alternate, opposite, whorled, basal rosette only), how the leaves attach to the stem, presence of hairs on stem and or leaves, color. Forb, vine, shrub, or tree?

20160505-_DSC0130 copy

wild sarsaparilla; how many leaves are there: one, three, or fifteen?

The leaves: are there any? simple or compound? smooth edges, or wrinkled, or toothed? Be careful here, as sometimes a compound leaf is so large and complicated, or the leaflets so well spaced, that you think you’re looking at many simple leaves when actually you’re looking at one large leaf.

Habitat: This is critical. Where is the plant growing? In sun or shade? On a steep slope or in a floodplain? Along a riverbank or even in the water? Swamp plants do not grow on hilltops. Spring ephemerals grow in woodlands, but they bloom and die back before the trees leaf out, so the habitat might be described as partly or mostly sunny despite all the trees.


marsh blue violet, growing almost in the water


partridgeberry, growing atop rocks

Season: if the plant normally blooms in May, you might see it blooming in early June (if you found it at the north end of its range), but you probably didn’t see it blooming in August.

Don’t look at just one plant! Have a look around for more of the same, and if you see variations, note them, and also note what seems typical.


Tomorrow: things change; beware the internet.






with plants in the aster family, the number of “petals” (they aren’t really petals) often varies from flower to flower on the same plant

Identifying Wildflowers, Part One: Using Books

clustered snakeroot closeup

Sanicula odorata (clustered sanicle)

A question on the Maryland Native Plant Society facebook page got me revisiting how I identify wildflowers. The more I typed (and the more I deleted), the more I realized it’s a rather complicated process, though it gets easier the more you do it, of course.

There is some great information on the internet but there is too much information. I suggest starting with one of the classic books. You will have to learn some basic terminology, but that’s part of the fun.

Newcomb’s Wildflower Guide (Lawrence Newcomb; Little, Brown and Company) has a logical key system that’s easy to use once you get the hang of it. You have to be able to answer very specific questions about the plants, but it isn’t forbiddingly technical.

Wildflowers in the Field and Forest (Steven Clemants and Carol Gracie; Oxford University Press) organizes by flower color. Within each color section the listings are further organized by leaf arrangement, then leaf type, then number of petals.

A Field Guide to Widlflowers/Northeastern/North-central North America (Roger Tory Peterson and Margaret McKenny; Houghton Mifflin Company) also organizes by flower color; within each section are headings like “Spurred Orchids in Showy Spikes”, or “Tight Pink Clusters, Tiny Flowers”, which makes flipping through a little easier.

If there’s a downside to Newcomb’s, it’s that plants in the same family (and sometimes genus) can be on different, non-contiguous pages, so you can’t look at similar things all at once. The problem with the other two guides is that flower color can vary – sometimes a lot. There are regional variations and there can be variations within the same stand of plants, especially when it comes to pinks and purples.  The first patch of moss phlox I ever found had pure white flowers, but in Wildflowers it’s in the “pink” section, while Peterson’s has it in the white, pink, and blue sections.

The pictures in Wildflowers in the Field and Forest are good, but mostly show the flower. Newcomb’s and the Peterson guide both have excellent drawings of flowers, leaves, and stems, and the drawings in Peterson’s have arrows to show the differences between similar species.

If I had to recommend just one book, it would be Newcomb’s, but with all three you should be able to identify all but the most obscure flowers (or latest alien invasives).

Books specific to the area you’re hunting in can be a big help, too. I’ve gotten a lot from Finding Wildflowers in the Baltimore-Washington Area (Cristol Fleming, Marion Blois Lobstein, Barbara Tufty; The Johns Hopkins University Press) and Eastern Woodland Wildflowers and Trees (Melanie Choukas-Bradley, Tina Thieme Brown; University of Virginia Press).

Wildflowers in the Field and Forest was published in 2006. I have the 1977 edition of Newcomb’s, (it was updated in 1989), and the 1998 edition of Peterson’s. I bring this up because of another problem: names change. More on that in Part Three.


The great blue heron (Ardea herodias) is a large bird that lives year round in most of the continental US (excepting the desert southwest and the Rocky Mountains). It can stand up to 54 inches tall, and is most often seen wading in shallow water looking for fish, or flying low along streams, or on older Maryland license plates (“Treasure the Chesapeake”). In the air the silhouette is unmistakable.


One morning in early May I saw eight of them among the cattails in the C&O Canal. A benefit to going out in cool and misty weather is that there are fewer joggers and bikers coming along and spooking the birds. I had a good long time to watch and snap pictures of these beautiful creatures.