A Blue Thing; a New Thing

Earlier this month, while searching the riverbank for showy flowers, I stumbled across two new-to-me flowering plants. Quite a surprise, considering how many species I’ve catalogued in the gorge over the past seven years.

The first was growing among cardinal flowers. I knew right away that it was in the mint family, and it didn’t take long to key out once I got home. Scutellaria lateriflora, aka mad-dog skullcap, is a medium-height forb of wet, sunny areas.


It appears to be one of the most widespread species of Scutellaria, occurring in almost all of North America except for the desert West and parts of western and northern Canada. The flowers are tiny, less than one centimeter long, and are borne on terminal and axillary racemes*.


The other find was ditch stonecrop, Penthorum sedoides. Older wildflower guides place this species in the stonecrop family (Crassulaceae), and very old guides place it in the Saxifragaceae; currently it is placed in a family of it’s own, Penthoraceae, with only one other species (P. chinense) and no other genera.

It does look like our native woodland stonecrop, but the plants aren’t succulent, and they prefer wet soils (unlike woodland stonecrop, which likes dry soils)**.



Ditch stonecrop ranges from Quebec to Florida, going west into the prairie; also one small area along the Oregon/Washington border, and maybe British Columbia. Probably it was introduced in these Pacific Northwest areas.



*Illinois Wildflowers  Dr. John Hilty

**Wildflowers of the Atlantic Southeast  Laura Cotterman, Damon Waitt, and Alan Weakley (Timber Press, 2019)

More Showy Summer Flowers

a huge stand of New York ironweed in a nearly dry river channel

As I worked my way along the Potomac River’s muddy banks last week, I watched for New York ironweed (Vernonia noveboracensis; Asteraceae). I hadn’t seen it in the wild in several years. I didn’t find it Monday or Tuesday, but I saw hundreds of plants on Friday. Some were only knee high, others were over seven feet tall; some grew singly, and others grew in huge colonies. Now I appreciate the word “weed” in its name.

Two (or maybe three, it’s not quite clear) of the 20 or so Vernonia species found in the US are native to Maryland. V. noveboracensis is a wetland species, while V. glauca is an upland species, so the easiest way to distinguish between them is to note where they’re growing.

One of the neat things about this species is that the inflorescence has only disc florets; there are no ray florets at all.




Joe-pye weed is another tall forb with showy flowers. I see it more often along the C&O Canal than along the river. There are two species found in the Maryland piedmont; this one is Eutrochium fistulosum, which prefers sunny, wet places. The other species (E. purpureum) prefers upland areas. Joe-pye weed is another aster family plant with only disc florets. By themselves they aren’t much to look at; it’s the huge masses of multi-flowered heads in multiple inflorescences that make the plants so showy.






Believe it or not, plants not in the aster family are blooming now, too. These two are in the mallow family (Malvaceae). The white one with the simple leaves is Hibiscus moscheutos (swamp rosemallow); the pinkish ones with the deeply lobed leaves are Hibiscus laevis (halberd-leaved rosemallow). Be wary of using color to tell them apart, as colors in both species can vary, especially in different parts of the country. The leaf shape is a more reliable differentiator.

Swamp rosemallow is common in the coastal plain, less so in the piedmont, and although halberd-leaved rosemallow is on the Maryland DNR watchlist, it seems fairly abundant along the Potomac in Montgomery County.

Last one for today: Lobelia cardinalis (cardinal flower). I’m always stunned by just how red these flowers are. I’ve never seen a wildflower in this area with such intense color. I was surprised by how common it is: look at the quad map from Maryland Biodiversity Project!

next time: something new

Summer Showstoppers

the Potomac River in early August, looking upstream from near Cabin John Creek

Spring is the time for the small, subtle things that emerge, grow, leaf out, bloom, fade, and die back to the ground before you know it. For many ephemeral species, you have two weeks at best to see the flowers.

thin-leaved sunflower stretching towards the sun

Summer, though… Summer is the time for big, showy, outrageous things. Plants taller than you are (joe-pye weed), leaves bigger than your hand (hairy leafcup), lurid colors (cardinal flower).  Many of these you won’t find in the woods, where flowers tend to be small (jumpseed, Indian-tobacco). The showy plants tend to like sunlight, so look for them in open woodlands, or at woods’ edge, or in meadows, or best yet, along riverbanks.

common evening primrose growing along a steep riverbank

That’s where I was last Monday and Tuesday. The weather was so nice, I couldn’t resist going to the Potomac Gorge to do some botanizing. Scrambling down steep banks and treading along the waterline I found over 40 different species of plants in flower.

Today I’m going to focus on the large yellow ones.


Common evening primrose (Oenothera biennis; Onagraceae) is found in every county in Maryland and most of the US.  It can grow over 6 feet tall in a variety of habitats. It’s hard to say how tall these were, as they were growing up a steep slope, but the ones closest to me were at least 5 feet.


Thin-leaved sunflower (Helianthus decapetalus; Asteraceae) is what we call a DYC*; these species can be difficult to distinguish, but this one can be identified by bracts under the flower head that exceed the width of the disk (click on the image to see it larger) and very long, narrow leaf tips (“acuminate” is the technical term). The specific epithet is not to be taken literally; the typical ray floret (“petal”) count is in the range of 8 to 15.

Hairy leafcup (Smallanthus uvedalia; Asteraceae) is another DYC, but this one is easily identified by the gigantic leaves with a unique shape. The few records in Maryland Biodiversity Project are mostly from the Coastal Plain and Piedmont, but a look at the USDA PLANTS Database distribution map makes me think that this species is under-reported. At any rate, I see hairy leafcup in the woods near openings in the canopy, close to the river but rarely in full sunlight. Usually I have to look up to see the flowers (I’m 5’5″ tall).

Here’s another big yellow astery thing: cut-leaved coneflower (Rudbeckia laciniata). The leaves make for easy field ID, but be sure to look at the whole plant; upper leaves are often much simpler in shape.

I was utterly thrilled to find this big, beautiful stand of purple-headed sneezeweed (Helenium flexuosum; Asteraceae) right by the river. Perfect habitat for this species: sunny and wet. How can you not love a flower with a name like that? Pearl crescent butterflies seem to love the flowers, too.

next time: big, showy, pink, purple


*damn yellow composite

Luna Moth

I’m back! And I have pictures to post over the next few days, and some new finds, but first I’m going to share my best find of 2020.

In the depths of the pandemic I took a day to check out the Carderock area and the Billy Goat C trail. Saw some lovely flowers, took lots of pictures; then, while walking fast towards home along the towpath, I spotted this big green thing near the ground, and it wasn’t a plant.

Only a few days before I had been reading about luna moths (Actias luna), and thinking how I’d never seen one, and wouldn’t it be nice to? And there it was, freshly emerged. I sat down at a respectful distance, mounted the camera on a tripod, and started shooting. Over the course of fifteen minutes I took about 40 photos as the moth slowly opened its wings. It was one of the high points of my year.

Once emerged from their cocoons, luna moths live less than a week. They don’t eat. They mate, females lay eggs, and they die. Read about The Life History of the Luna Moth on the Finger Lakes Land Trust website.

Check back tomorrow for new wildflower pictures!
further reading