Botanizing at Creve Coeur Lake

Mallard Lake at Creve Coeur Lake Park.

The forecast over the weekend called for possible rain, so the WGNSS Botany Group chose a location close to home in case we got rained out. I would have never thought of Creve Coeur Park as a place to botanize, but the environs surrounding the lakes, particularly Mallard Lake, get good moisture and have been allowed to revert to semi-native vegetation (with a few significant exotic invasives) for many years now. We first examined a few native garden plantings near the parking lot and saw several things not typically found in this part of the state, but the most interesting to me was Liatris scariosa (savanna blazingstar), one of our less common species, and it’s large fantastically showy blooms.

Liatris scariosa (savanna blazingstar) inflorescence.
Liatris scariosa (savanna blazingstar) floret.

Eupatorium serotinum (late boneset) was blooming profusely along the margins of the lake—I scanned the flowers for a while hoping to see some interesting beetles, with several Euphoria leucographa (a common flower chafer) being the only beetles seen. As I looked, I enjoyed Steve’s explanation of the common name of late boneset compared to another common Missouri species, Eupatorium altissimum (tall boneset)—the former actually blooms later than “late boneset,” and the latter is actually as tall as “tall boneset”!

Further along the lake margin we found a stand of “Helianthus” sunflowers, but these proved to be the lookalike Heliopsus helianthoides (false sunflower)—I’d been fooled by their straight yellow color versus the orange-yellow color that is more typical of the species. A good character to distinguish this species when the color is not diagnostic is the double-rank of phyllaries on the underside of the flower head, with the inner ones short and rounded and the outer ones long and pointed-recurved.

Heliopsus helianthoides (false sunflower).
Heliopsus helianthoides (false sunflower) inflorescence.
Heliopsus helianthoides (false sunflower) involucre.

There is also another easy way to distinguish false sunflower—by noting the presence of Lygaeus turcicus (false milkweed bug, also called the heliopsis bug), a close relative of L. kalmii (small milkweed bug) which looks very similar to the latter but, as indicated by the common name, feeds exclusively on false sunflower instead of milkweed. We eventually found several of the bugs (which, sadly, did not cooperate for photos), further confirming our identification of the plants.

We diverted to a dry, sandy spot under the bridge to check out some ant lion pits. Also called “doodlebugs,” these relatives to lacewings are surely the inspiration for the brain-eating “Ceti eels” in Star Trek: The Wrath of Khan! In the area, a super-fresh Limenitis arthemis astyanax (red-spotted purple) probed for salts on the ground, posing beautifully for a few photos.

Limenitis arthemis astyanax (red-spotted purple).

Walking along the trail north of Mallard Lake, we saw two species of vining plants: Amphicarpaea bracteata (hog peanut), and Apios americana (groundnut). Both of these plants belong to the bean family (Fabaceae) and have underground edible portions—the former in the form of peanut-like fruits formed from self-fertilizing, “cleistogamous” flowers that bloom near the ground (or even underground), and the latter in the form of tubers that form like strings of beads along the underground rhizomes of the vine. Both were important food sources for indigenous cultures. I’ve never seen either of these species in bloom (the flowers of groundnut, in particular, were unlike any other I’ve seen), so it was nice to be able to compare them on plants growing nearly side-by-side.

Amphicarpaea bracteata (hog peanut) inflorescence and leaves.
Amphicarpaea bracteata (hog peanut) inflorescence.
Apios americana (groundnut).
Apios americana (groundnut) inflorescence.
Apios americana (groundnut) leaf.

Walking back towards the cars, we had one more “DYC” (damned yellow composite) to test our ID skills. Fortunately, Helenium spp. (sneezeweed) are easily distinguished from other DYCs by their wedge-shaped ray florets with lobed tips and protuberant, nearly spherical disks. Helenium autumnale (common sneezeweed) is identified to species by its combination of yellow disk florets and broad leaves attached to a conspicuously winged stem.

Helenium autumnale (common sneezeweed).
Helenium autumnale (common sneezeweed) inflorescences.
Helenium autumnale (common sneezeweed) stem/leaves.

By the time we reached our cars, I was as hungry, sweaty, and thirsty as I’ve ever been on one of these walks. My thirst and appetite for knowledge, however, were, for the moment, completely satiated.

A dragonfly perched on the branch above me.

©️ Ted C. MacRae 2021

Plant of the day – Agalinis skinneriana (pale false foxglove)

Agalinis skinneriana (pale false foxglove).

Continuing hot and very muggy during the last week, and today it was already in the low 90s by the time I got into the field a little before noon. Silphium terebinthinaceum (prairie dock) and old Solidago nemoralis (field goldenrod) are are in full bloom across the glade, and I noticed pre-flowering plants of what must be a different goldenrod species and a different blazing star. I suspect they will be in full bloom by the time I check the traps again at the end of next week. The plant of the day, however, was Agalinis skinneriana (pale false foxglove), not a true foxglove but rather a member of the family Orobanchaceae. Midwestern gerardia is another common name for the species, and like other members of the family it is a hemiparasitic annual forb.

Agalinis skinneriana (pale false foxglove).

This plant is relatively uncommon, both in Missouri, being found primarily in glades, upland prairies, and in the few other states in which it is found, and though I’ve not noticed this plant here previously I found at least a few individuals in both the east and the west parcels. The upward-facing flowers are a key attribute for identification in the field. The two upper corolla lobes are spreading to reflexed, and the plants are relatively slender, being fewer-branched and less bushy than the more common A. tenuifoliaand A. gattingeri.

©️ Ted C. MacRae 2021

Botanizing at Pickle Creek Natural Area

View atop a sandstone hoodoo.

Our destination for this week’s Monday field trip with the Webster Groves Nature Study Society (WGNSS) Botany Group was Pickle Creek Natural Area. This gem of a site has one of the most natural history action-packed 2.5 miles of trail in Missouri, featuring moist sandstone canyons, fascinating sandstone “hoodoos,” and unique sandstone glades. Fr. Sullivan got there early to beat the heat and had a few interesting things to show us in the small sandstone glade (more correctly called a xeric sandstone prairie) near the trailhead. These included two new-to-me glade specialists: Hypericum gentianoides (pineweed), and Trichostema dichotomum (blue curls).

Hypericum gentianoides (pineweed).
Hypericum gentianoides (pineweed).

Beginning along the trail we saw two species of aster still not quite ready to bloom: Symphyotrichum anomalum (many-rayed aster), with its distinctively reflexed phyllaries, and S. patens (spreading aster), distinctive by its strongly clasping leaves with rounded basal auricles. Two species of goldenrod were also present: the very common Solidago nemoralis (old-field goldenrod) in early bloom, and the very conservative (CC value = 8) S. buckleyi (Buckley’s goldenrod), its buds still growing for bloom in early September. Passing through the first of many deep cuts through the sandstone, we saw a small Aralia racemosa (American spikenard)—cousin to the devil’s walking sticks (A. spinosa) that we saw last week in southeastern Missouri. The plant was already past bloom and sporting bright red-purple berries.

Aralia racemosa (American spikenard).
Aralia racemosa (American spikenard).

Further down into one of the moist valleys, we found one of our objectives: Goodyera pubescens (downy rattlesnake plantain). I have seen this native orchid many times, as it’s distinctive white-veined leaves are a prominent winter sight in this area; however, this was the first time that I’ve seen them in bloom. Most of those with flower stalks were a bit past peak bloom, but we found at least a couple of plants still with good flowers for photographs. There were also many more basal leaf rosettes in the area without flower stalks, indicating a good population.

Goodyera pubescens (downy rattlesnake plantain).
Goodyera pubescens (downy rattlesnake plantain).
Goodyera pubescens (downy rattlesnake plantain).

The sandstone hoodoos of the area are among its most unique feature, and John showed us a spot on one of them where all three Missouri species of Vaccinium (a genus of plants in the blueberry family) can be found growing right next to each other: V. arboreum (farkleberry), V. pallidum (lowbush blueberry), and V. stramineum (deerberry).

All three Missouri Vaccinium species can be seen in this photo: V. arboreum (farkleberry) at upper right, V. pallidum (lowbush blueberry) at right-center, and V. stramineum (deerberry) at lower left.

The last mile of the hike was more difficult due to the heat, but the deep, sandstone canyons and moist north-facing bluff still provided visual interest and a bit of cool relief. At the end of the hike, John almost tripped over a Geotrupes splendidus (splendid earth-boring beetle) lumbering across the trail.

©️ Ted C. MacRae 2021