One Reason to Plant Native Flowers






When I don’t have time to write meaningful content, I post pretty pictures. Here are a few of a spicebush swallowtail on Eutrochium fistulosum (joy-pye weed, Asteraceae) in my garden. The plant also attracts monarchs, eastern tiger swallowtails, and lots of skippers and bees.

I hope to get back to writing some time next week. Apologies for the lapses.

Sometimes You Get a Little Lucky

Walking along the C&O Canal Towpath with a new lens on the camera (70-200mm), I spotted a nice wingstem (Verbesina alternifolia) along the bank. Camera was at f/8, ISO 100 (my default settings). I adjusted the focal length to frame the picture, set the shutter speed at 1/125s, focused, et voila! A hummingbird decided to check out the flower.

Less then one second later it was in flight again. It’s the blur on the upper right.

If it had stayed any longer I would have tried again with different settings. Oh well.

I’m so behind. I have lots of pictures to post but just not a lot of time to write. Hopefully there will be more content here in the coming weeks.


Of the four species of Hibiscus (Malvaceae) that grow in the Maryland Piedmont, two are alien (rose of Sharon and flower of an hour), and two are native. Starting in mid-July every year, I spend hours scouring the banks of the Potomac looking for these big, showy flowers.

Not that they’re hard to find. Despite being listed S3 (“At moderate risk of extinction or extirpation due to a fairly restricted range, relatively few populations…”), I see Hibiscus laevis (halberd-leaved rosemallow) by the hundreds.

The tricky thing is getting a good angle to shoot them. Halberd-leaved rosemallow is a wetland obligate, and with the flowers usually facing the river, the water level has to be low for me to get close enough to take decent pictures.


Hibiscus moscheutos (swamp rosemallow, crimson-eye rosemallow) is also a wetland obligate. It should be more common than H. laevis, but before this summer I had only seen them in the C&O Canal. This year I found several along the river banks.

The flowers of both species are about the same size. H laevis generally sports pink flowers, but they can be very pale, almost white, while H. moscheutos flowers are generally pure white. Both have a crimson throat. Color isn’t a reliable way to distinguish between them, though. Instead look at the leaves.



<—Hibiscus laevis leaf





Hibiscus moscheutos leaf—>


Even though I’m particularly attracted to small, subtle, hidden things, there’s something compelling about the rosemallows.

Love ’em or Hate ’em: the Milkweeds

True to their name, milkweeds are both milky and weedy. “Milk” refers to the white latex found within, a chemical defense against herbivory. And the plants are weedy: some species are on US state and Canadian province weed lists. Farmers hate them because many species are tall plants with massive root systems that can out-compete crops.  But most of the rest of us love them for attracting bees and butterflies.

I love them because the flowers themselves are fantastically complex.

The inflorescence is an umbel. Each individual flower consists of five sepals and five petals, and in most species five hoods and five horns. The hoods enclose the gynostegium, a complex structure consisting of fused stamens and styles that is unique to the genus Asclepias. It gets even more complicated than that; if you’re interested in the topic, there’s a detailed but not too technical explanation at the Orbis Environmental Consulting website.

The genus Asclepias was once placed in its own family, Asclepiadaceae, which is what you’ll find in older texts. Currently it’s place in the Apocynaceae (dogbane family), subfamily Asclepiadoideae. A dozen species of Asclepias can be found in Maryland, all native and all but one occurring in the Piedmont.

Asclepias incarnata (swamp milkweed) is found in most of the US except Alabama, Arizona, and the Pacific coast states, and in the eastern half of Canada. It prefers wet soils, and can grow two to six feet tall. The leaves are narrower than those of most other milkweed species. In the Potomac Gorge I’ve seen it blooming from late June to late August.

Asclepias quadrifolia (four-leaved milkweed) has a more limited range: it’s found in Ontario and the eastern half of the US, excepting some of the northernmost and southernmost states, and seems to be concentrated in the Appalachians and the Ozarks. It’s endangered in New Hampshire, threatened in Rhode Island, and uncommon in Vermont (per the New England Wild Flower Society). The species prefers drier soils in woodlands. The whorl of four leaves makes it easy to identify.

Asclepias syriaca (common milkweed) is found in the eastern US and Canada and a few western states, generally in full sun on dry or poor soils. In the Potomac Gorge I find it in soil pockets on the bedrock near the river, blooming in mid June to mid July. It’s on several authorities’ weedy plants lists. The flowers are a dusky pink as opposed to the bright pink of swamp milkweed, and the leaves are much broader.

Asclepias verticillata (whorled milkweed) is found in most of the eastern and central US and Canada, in open areas with full sun and poor soils. It’s on several weedy plants lists, but is also threatened in Massachusetts and special concern in Rhode Island. In Maryland it’s S3/watchlist. I’ve never seen it in the wild; the plant pictured here survived the rabbit onslaught in my garden. Note how narrow the whorled leaves are.

Asclepias viridiflora (green comet milkweed) is widespread across the US and Canada, though missing from the West and most of New England. It’s endangered in Florida, threatened in New York, special concern in Connecticut. It’s uncommon in Maryland; look for it blooming from mid June to mid August in dry open areas, especially serpentine barrens.

This last one is not technically a milkweed, but it’s close. Cynanchum laeve (honeyvine) is a sprawling vine that’ll grow up and around everything, so it is weedy. And it does exude latex. And monarch caterpillars (and other milkweed butterfly caterpillars) do feed on it, so you may as well think of it as a milkweed. In Maryland it’s found in the coastal plain, and also in the Piedmont part of Montgomery County. I’ve been seeing it along the banks of the Potomac, twining ’round late-flowering thoroughwort, rosemallows, and anything else it can get to.

Great Things About August

It’s 6:44 am as I put the finishing touches on this post, 77°F already and 94% humidity, and yet I love August. It isn’t quite as hot as July; fresh, local peaches and tomatoes are everywhere; and half the DC area population is on vacation, so traffic is better and restaurants are easier to get into.

And it’s the time for big, showy wildflowers along the Potomac River.

The river has been running unusually high for this time of year, but last Monday it had finally dropped enough that I was able to explore the banks. Worth it in this weather? You bet. Here’s what I saw blooming.

Asclepias incarnata (swamp milkweed), one of the latest-blooming milkweed species. More on milkweeds in an upcoming post. This particular stand had several monarch butterflies feeding on it.



Conoclinium coelestinum (mistflower)





Eutrochium species (joe-pye weed)

I’m cheating a little. Out on the trail I found E. purpureum, but they were kind of ratty looking. Pictured here is E. fistulosum in my garden, with a spicebush swallowtail.


Helianthus decapetalus (thin-leaved sunflower)




Hibiscus laevis (halberd-leaved rosemallow)





Hibiscus moscheutos (swamp rosemallow)

Look for more about rosemallows in an upcoming post.



Lobelia cardinalis (cardinal flower). I can never get over that lurid red.





Here’s a closeup of one in my garden. This is a true wetland plant that can’t survive in dry soils. I had to give this one plant about 2 gallons of water each day during our July dry spell, and that was barely enough.


Oenothera biennis (common evening primrose)




Persicaria coccineum (scarlet smartweed)


 I had a lively discussion going about this one on-line recently. The Polygonaceae is a difficult family. I’ll save the details for a future post.


Senna hebecarpa (wild senna)



Smallanthus uvedalia (large-flowered leafcup) [below]

Solidago simplex var. racemosa (racemose goldenrod) [left]

Verbesina alternifolia (wingstem)


Also seen (no pictures):
Commelina virginica (Virginia dayflower)
Cynanchum laeve (honeyvine, a type of milkweed)
Eupatorium serotinum (late-flowering thoroughwort)
Ipomoea pandurata (wild potato vine)
Mimulus alatus (winged monkeyflower)
Persicaria virginiana (jumpseed)
Phyla lanceolata (fogfruit)
Rudbeckia laciniata (cut-leaved coneflower)
Veronicastrum virginicum (Culver’s root)