Astery Things #4: Blue Mistflower

Next in the series of posts on composite flowers lacking ray florets is blue mistflower. Like the joe-pye weeds, blue mistflower was once placed in the genus Eupatorium, but nowadays it’s known as Conoclinium coelestinum. The flowers are somewhat similar in appearance to joe-pyes, the heads of tightly clustered disk florets with long protruding styles giving the inflorescences a fine, feathery, misty look.

click on this one to zoom in and see the minute flowers opening on the outside of the heads

Also like joe-pye weeds, blue mistflower likes wet soils; along the banks of the Potomac River, if I see joe-pyes, I’m almost certain to find blue mistflower nearby. Unlike joe-pyes, the plants are short, getting to about two feet tall in ideal conditions.

Speaking of the Potomac, I went back out to check on the spot I reported on last week, a place where in other years I would definitely find mistflower. It was all underwater again. Lots of rain upstream.

Blue mistflower ranges mostly along the Mississippi River basin and its tributaries, from southern Illinois south, and also in the eastern mid-Atlantic and the Carolinas. It’s found in most of Maryland except for the westernmost and easternmost parts of the state.

eastern tailed-blue butterfly (Cupido comyntas) sipping from mistflower

Apparently these flowers are a great nectar source for a variety of butterflies, but I haven’t seen many on it. Three years ago I wrote that I was worried that the blue mistflowers in my garden would become weedy*. “Weedy” is, of course, in the eye of the gardener. They certainly have spread, somewhat aggressively, and I’ve had to pull some out, but they haven’t reached weed status yet.


*Lepidopterans Photobomb My Mistflower Shoot



Eupatorium perfoliatum

I’m not sure what compelled me to look closely at this particular cluster of tiny white fuzzy flowers.  They’re all over the place at this time of year, in the form of late-flowering thoroughwort and white snakeroot.  But for some reason I pulled the kayak up close to this one islet near Fletcher’s Cove, and there it was.


This was a big deal because I’ve never actually seen this plant, despite it being fairly common.  What sets it apart from the other Eupatoriums is the paired, clasping, opposite leaves that make it look like the stem is piercing a single leaf.

There’s nothing about the flowers to distinguish them from other bonesets or thoroughworts.

Boneset likes sun or a bit of shade and wet soils and is tolerant of flooding, so the rock outcrops near the banks of the Potomac are perfect habitat for it.  The native range is from Texas north into Manitoba and all the way east to the Atlantic.

The genus Eupatorium once contained hundreds or species, including (in this area) the various bonesets/thoroughworts, mistflowers, snakeroots, and joe-pye weeds.  Those last three have been moved to other genera, but that is a subject for another day.


…hey, what about the other white flowers in that picture?  Stay tuned!

Lepidopterans Photobomb My Mistflower Shoot


I’ve been trying for two weeks now to get some up-close, detailed shots of various flowers to write a post about plants currently and formerly classed in the genus Eupatorium.  With blue mistflower it’s fairly easy as there’s a nice clump growing in my garden.  But a skipper and a butterfly just wouldn’t leave the plants alone.  I’m not complaining; it was a good opportunity and a pleasant way to spend time on a lovely afternoon.


blue mistflower (Conoclinium coelestinum; Asteraceae)
a skipper (little glassywing?)
eastern tailed-blue butterfly (Cupido comyntas)
20150823-_DSC0103 20150823-_DSC0104 20150823-_DSC0105

Blue mistflower is a common plant of partly sunny, wet places – you’ll see it frequently close to the banks of the Potomac, where it blooms from mid to late summer (at least). It can be found from Florida north to New York, east to Texas, and from there north to Nebraska.  It’s a nice native alternative to the similar-looking common garden plants known as ageratum, about which a plantsman at a botanic garden where I used to volunteer would always roll his eyes; he called them “droopy Maryland swamp plants”.  Don’t know where he got “droopy” from.  Anyway, they are growing so vigorously in my evergreen garden – which isn’t particularly wet – that I’m a bit worried they’ll become weeds.

Flower of the Day: Mistflower

Conoclinium coelestinum; Asteraceae (aster family)


Yet another in the series of Eupatorium-type flowers, formerly named Eupatorium coelestinum.  Note once again how similar the flowers are to the others I’ve posted about in the last few days.  This plant grows up to three feet tall, and has triangular leaves with short petioles. It’s closely related to the common garden plant ageratum. Its native range is from Ontario and New York south to Florida and west to the central and southern Great Plains.

Here’s a picture showing flowers, buds, and the characteristic leaves:

20140806-DSC_0102 and one more picture for fun20140811-DSC_0274.