Look at the Sweet Phyllaries on that One!

A look at the disk and ray florets of Symphyotrichum patens (late fall aster)

A lot of folks don’t seem to like attempting to identify plants in the Asteraceae family, more commonly known as the asters. This is a very large family of plants and there are definitely many difficult cases out there in terms of identifying. However, with a good dichotomous key, a hand lens and some patience, I think most anyone can have success in learning some of these interesting plants. The key is learning what characteristics are “key.” The group I am featuring here are three members of the Symphyotrichum genus, often referred to as the “new world asters.” Following recent taxonomic revisions, the genus now holds more than 100 species, of which about 25 can be found in Missouri. Most ray flowers are light blue to violet but some can be white or pink as well.

Photographs can be useful when attempting to identify the new world asters. These can be referred to when attempting identification on your own or sending to someone with more expertise on the group. Knowing what to photograph is important.

A good look at the distinctive involucre of Symphyotrichum patens.

First, both sides of the flower, referred to as the capitulum (composite inflorescence) in the asters, is important in making an identification. Photograph the ray and disk florets along with the involucre from the underside should be photographed. The involucre is a protective structure composed of a group of phyllaries (bracts) that can be beneficial in discerning between species. Asters in this group can be distinguished from one another by the number of ray florets per capitulum and the size of the flowerheads 

The growth habit of Symphyotrichum patens.

Two other photographs you will want to take when attempting to ID the Symphyotrichum are of the plant’s growth habit and the leaves – particularly details of how the leaves are attached to the stems. There are usually key differences here that will be useful when making an identification. Unfortunately, I neglected to take closeups of the leaves while working with these three plants in the front yard this past autumn.

The next species I would like to feature is the spectacular Symphyotrichum oblongifolium, or “aromatic aster.” These plants are quite impressive. Pinch them back once sometime in the month of June and they will bush out, forming impressive globes of violet blooms. The accompanying habit photos are from our front bed and is only three plants! Although these plants create enormous amounts of blooms, I find that it is almost too late in the year. Most of the blooms don’t open until well into October. During this time, most of the pollinators that visited these blooms were honey bees, at least in my yard. I think most of the native pollinators had finished their season by this point.

The above images show the growth habit at flowering of Symphyotrichum oblongifolium.

I hope the next couple of images exemplifies how the phyllaries are important diagnostically for identifying these plants whose flowers look very similar when viewed head-on.

The capitulum of Symphyotrichum oblongifolium. Notice how strikingly different the involucre is compared to S. pattens.

The straw-colored disk flowers of Symphyotrichum drummondii will turn maroon to purple in color late in the season.
Symphyotrichum drummondii – named after Scottish botanist Thomas Drummond, who spent time in St. Louis prior to his famous plant collecting trip to Texas in the 1830s.

Finally, the third member of this genus I have tried in the front yard beds is Symphyotrichum drummondii (Drummond’s aster). This one looks a lot different from the other two, not only in the characteristics of the capitulum, but in its growth habit as well. This is much more of a small, dainty plant that is found in open woodlands and savannahs in the northern sections of Missouri.

A look at the narrow and widely-spaced phyllaries of Symphyotrichum drummondii.

Fruits of Fall

Tonight I’m sharing a couple of fascinating fruits that Pete and found on a late October hike from last year. Both of these plants are in the bittersweet (Celastraceae) family.

First up is Euonymus atropurpureus, or the eastern wahoo. This is a relative of the strawberry bush but is much more widespread across the state. I put one of these in the yard this past fall and am hoping it will establish itself. Like the strawberry bush, this fruit will split in autumn or winter, exposing four scarlet seeds.

Fruits of Euonymus atropurpureus (eastern wahoo). Photographed on 21/OCT/2021 in St. Francois County, MO.

Next up is Celastrus scandens (American bittersweet), a twinning woody vine that sometimes behaves as a bush. Pete and I enjoyed a few of these sweet, intensely-red fruits. Thankfully, we did not enjoy too many as I read afterwards that these are mildly toxic if eaten. Neither of us felt any ill effects afterwards.

Fruits of Celastrus scandens (American bittersweet). Photographed on 27/OCT/2021 in St. Francois County, MO.

-Ozark Bill

Euonymus americanus (Strawberry Bush)

Euonymus americanus in bloom. Strawberry bush usually blooms in mid to late May in MO. This species can be difficult to distinguish from the other bushy Euonymus in the area, including the invasive Euonymus alatus (burning bush). When not in bloom, E. americanus is the only bushy Euonymus that has five petals, all the remaining having four.

Ranked as an S2 (imperiled) species of conservation concern in Missouri, Euonymus americanus is a striking plant in more than one season. Where it grows in the Show Me State it is always threatened by white-tailed deer who absolutely love our native Euonymus spp. In areas with overpopulation of deer, the plant has been removed from the landscape. This past autumn, I planted one in the fenced-in portion of our backyard in the remaining humus and decay of an old ash stump. I’m hoping the soil here will be rich enough for its liking and that the deer will not discover it.

The unique and unmistakable fruits that give strawberry bush its name. This plant was found in Butler County, MO.

Hydrolea (Water Leaves)

A couple of interesting Missouri Natives from a monogeneric family – the Hydroleaceae. The genus, Hydrolea, comes from the Greek hydor (water) and eleia (olive), referring to the wet habitats these plants prefer (they definitely like their feet wet and can withstand long periods of partial to complete submersion) and their leaves resemblance to the leaves of the olive. The flowers of these plants are downright stunning – these shades of blue are pretty rare in the flora of Missouri.

Hydrolea uniflora, photographed at Big Cane Conservation Area, 22 August 2021.
Hydrolea ovata is ranked S2 (imperiled) in the state of Missouri. This plant was photographed at Tingler Prairie Natural Area in Howell County, MO.

Thalia dealbata (Powdery Thalia)

Thalia dealbata, or powdery thalia, is a fascinating plant that I was introduced to this past August while on a botany trip with Pete Kozich and Stephen Dilks. A member of the mostly tropical arrowroot family (Marantaceae), T. dealbata is the only member of this family to be found in Missouri and only in the low and wet areas of the southeastern portion of the state. We found these plants a little late in their flowering season but with a few blooms in prime condition remaining at Otter Slough Conservation Area.

A closeup look at the mirrored pair of flowers of Thalia dealbata (powdery thalia).

The leaves of Thalia are what the plants are primarily known for, looking very reminiscent of the cannas and very tropical in appearance. However, doing a little research after seeing these guys for the first time, I have become fascinated with the flowers and the pollination mechanism they developed. First of all, what appears to be a single flower in the image posted here is actually a pair of blooms in mirror image of each other. Additionally, the gorgeous purple petals are not petals at all but highly modified and sterile stamens (staminodes). This is just the beginning of the weird story of these flowers. These staminodes are key to a pollination strategy that literally throws pollen in the face of and often ends in the demise of all but the strongest of would-be insect pollinators. I was going to attempt to try and describe the pollination biology of this system, but this has been expertly described by Price and Rogers in a 1987 article published in Missouriensis. I highly recommend you give this a read!

Pete standing behind a nice batch of Thalia dealbata.

Agalinis fasciculata (Fasciculate False Foxglove)

Agalinis fasciculata, known as the fasciculate false foxglove and beach false foxglove was one of the more fascinating and unexpected plants I became acquainted with this year. A member of the Orobanchaceae family, this species is an annual hemiparasitic plant that does well in poor and sandy soils. I photographed these plants at the Missouri Mines State Historic Site in St. Francois County.

The genus Agalinis comes from the Greek – agan, meaning ‘very’ and linon, refering to ‘flax’, apparently in reference to the similarity of the flowers to those of flax. The species and common names refer to the fasciculate, or bundled manner in which the leaves are attached to the stem – something I failed to take any photos of this year. In my defense, much of the stem and leaves of these plants in mid-September were beginning to senesce and were not very photogenic.

Agalinis fasciculata (Fasciculate False Foxglove) in glorious bloom at Missouri Mines State Historic Site.
Many species of bees and flies like this syrphid fly act as pollinators of Agalinis fasciculata.
A rare six-lobed corolla of Agalinis fasciculata. This was the only six-lobed flower I found among hundreds I observed on this visit.

Eryngium prostratum (creeping eryngo)

Eryngium prostratum is an odd little member of the Apiaceae family that is found in the southeastern most part of Missouri. Along with it’s blue flowering heads, its closet living relative in Missouri is the relatively gigantic E. yuccifolium. These plants were photographed at Charleston Baptist Association Prairie in Scott County, MO on June 27, 2021.

Eryngium prostratum, or creeping eryngo, is a prostrate plant that roots at nodes as it creeps. It stays quite close to the ground and can be difficult to find.
Eryngium prostratum – not your typical carrot!

Styrax americanus (American Snowbell)

Found in approximately nine counties in southeastern Missouri, Styrax americanus can be found in low-lying wet habitats. This individual was found at Mingo National Wildlife Refuge. This plant is one of many different hosts of the promethea silkmoth (Callosamia promethea).

Styrax americanus – the American Snowbell. Photographed on May 22, 2021 at Mingo NWR near Puxico, MO.