Forked Blue Curls (Trichostema dichotomum) and an Explanation of Focus Stacking

I know I posted some similar pics last year, but I can’t get enough of these flowers. Although we literally had thousands of these flowers blooming in the yard this year from seed I collected last fall, I didn’t get around to photographing them until on a WGNSS Nature Photo Group trip to Don Robinson State Park in early September.

Forked Blue Curls (Trichostema dichotomum)

These flowers are both tiny and deep in multidimensions. Because of this, a narrow aperture is typically required to photograph with enough depth of field to get all parts of the flower in reasonably sharp focus. However, stopping down the aperture needed for this greater DOF comes with a couple of problems. First, adjusting the aperture too much above f/14 or so begins to dramatically lower sharpness due to the diffraction of the incoming light. Second, and probably more importantly, a small aperture will also bring more of your background into focus. Depending on the closeness and business of the background, this can simply ruin a nice composition.

So, what’s another alternative to stopping down? This flower is a perfect example of when it is a good idea to use focus stacking. In focus stacking, the photographer takes several images at a lower aperture to get “slices” of the subject in focus. Depending on the size of the subject, the focal length of the lens you are using and the magnification you are shooting it at will determine how many of these slices are required to get the entire subject covered. Then, you combine the individual images, or slices, in the computer to hopefully get a perfectly sharp subject with the creamy out-of-focus background that makes a nice image.

Forked Blue Curls (Trichostema dichotomum)

For my macro focus stacking, I typically use a 180mm macro lens and shoot at f/8. Depending on the criteria mentioned above, I will typically need 10-50 images to cover a subject. There are a few ways you can go about taking the images needed for a focus stack. You can shoot them manually, typically taken on a tripod and moving the focus ring a little at a time, or by using a macro focusing rail, which you move your rig closer to the subject for each image. If you are using an autofocusing lens, there are also automated ways to collect the images needed for a focus stack. The one I use is a specialized extension tube that has a computer chip inside. I let the extension tube know what the focal length is of the lens and the aperture I have the camera set to, make sure my focus is just before the first part of the subject I want to focus on and then hit the shutter release. The camera will then take image after image, changing to a deeper focus with each one until either I feel I have covered the entire subject or the lens hits infinity. Finally, newer cameras allow you to focus stack using controls built into the camera’s software. These typically provide a wide range of options for the photographer to control. I imagine using this has somewhat of a learning curve. I have not used this in my Canon R5, partly because I like the simplicity of what I use and partly because you cannot use flash when using this feature in Canon cameras to date.

If you’re having troubles getting the types of images you want of small subjects under high magnification, give focus stacking a try. But, remember, your subjects need to be stationary!


Regal Fritillary (Speyeria idalia) at the Cole Camp Prairie Complex

A regal fritillary (Speyeria idalia), photographed at Friendly Prairie, feeding on Asclepias tuberosa, one of the only species in bloom at the time of our visit.

Back in late June, Miguel and I took a trip to the “Cole Camp Prairies” near Sedalia MO. Here, we were after a target I had long wanted to photograph, the regal fritillary butterfly (Speyeria idalia). Once abundant across the ancient prairies, lands that are now mostly used to grow the crops feeding us, the regal fritillary are now listed as a G3/S3 species, meaning they are vulnerable to extinction. The reason for this is that the regal fritillary host plants are violet species that only grow in the scarce remnants of the once vast ocean of prairies that covered much of the central United States. Fewer acres of prairie means fewer prairie violets that leads to fewer butterflies. Fortunately, the pitiful amount of prairie remnants left in the Show-Me State do still support this fantastic butterfly and Miguel and I did our best to find and photograph some.

The Cole Camp Prairie complex is a list of approximately eight mostly postage-stamp sized publicly accessible prairies located north of the small town of Cole Camp in Benton County. I did some research to find out which prairies had confirmed sightings in the previous years and which were more likely to have a sizeable population. I knew we would focus on these, but because these prairies are pretty close to one another, we wound up visiting seven locations just to see the differences between them and to give the entire area a good scouting for the regals.

Photographing a butterfly on the wing is no easy task! A regal fritillary (Speyeria idalia) male searches for one of the first females to emerge at Paint Brush Prairie.

Our first stop was at Paint Brush Prairie Conservation Area. This is one of the larger of the Cole Camp Prairies and was reported to hold one of the better-sized populations of regals. Our visit coincided with the early portion of the regals flight period and this would hold ramifications that would complicate the achievement of our goals. Here, we did find an estimated two dozen regals. However, these were all most likely males that typically emerge earlier than females. Although some plants were in bloom, these males were not interested in feeding. Instead, they were constantly cruising, inches above the vegetation, assumedly waiting for one of the first females to emerge and an opportunity to mate. We tried our best. Once in a while, one would stop to rest for a brief second or two, but it was never long enough to get in position, find focus and take the shot. I then tried to see if it was possible to photograph them in flight. This proved to be about as fruitless as it sounds. After hundreds of shots, I wound up with only a single keeper, pictured here.

A regal fritillary (Speyeria idalia), photographed at Friendly Prairie, feeding on Asclepias tuberosa, one of the only species in bloom at the time of our visit.

Our next stop, just a quick drive west, was at Friendly Prairie C.A. This wound up being our most successful stop. Success in photographing these beasts lies in your visit’s timing with flowering plants. In late June, we missed the prolific blooming of most of the Echinacea and Asclepias and were a tad too early for the blooming period of the native Cirsium that support the energy needs of these butterflies over mid to late summer. Thankfully, we did find a few Asclepias tuberosa at peak bloom and the regals had found them as well. We only found four regals here, but they were cooperative indeed!

Miguel, ready for action at Friendly Prairie C.A.
A Halloween pennant photographed at Hi Lonesome Prairie. Notice the parasitic water mites that dragonflies often carry on the bottom of its thorax.

We continued our tour of the Cole Camp Prairies, visiting the holdings that the Missouri Department of Conservation had to offer as well as one restoration property owned by The Nature Conservancy. Towards the end of our time, we stopped at the largest prairie parcel in the area – Hi Lonesome Prairie C.A. This prairie was very dry and, perhaps consequentially, we found very few plants in bloom. There were, however, still a number of butterflies. Here we found monarchs and a diversity of swallowtail species as well as five regals. Almost all of these were flitting around the bushes that spotted the prairie’s many hillsides. This prairie also held some nice bird diversity. In addition to the ubiquitous Dickcissel, we found Grasshopper Sparrows, Henslow Sparrows, and Bell’s Vireos. Around a couple of this area’s large ponds, dragonflies were in abundance as well. I took some time to hop the electric fence around the larger pond, finding out the hard way that it was indeed working to keep out the cattle that graze the prairie, and spent some time working with gorgeous Halloween pennant’s (Celithmis eponina). See attached photo.

A regal fritillary (Speyeria idalia), photographed at Friendly Prairie, feeding on Asclepias tuberosa, one of the only species in bloom at the time of our visit.

I had wanted to give the Cole Camp Prairies a good tour for quite a while. I’m happy that we spent the day doing this although I know it was but a snapshot over the course of the seasons. Finding the number of regals we did was thrilling and I’m happy to have gotten a few worthwhile photos from the day. Although these prairies are a good hoof from the StL, at a little less than a three-hour drive, they are still much easier than getting to other prairies in different parts of the state. Hopefully my next visit comes soon.


Catalpa Sphinx (Ceratomia catalpae)

Miguel and I found an aggregation of the catalpa sphinx moth caterpillars on a caterpillar hunt in early September. I have been looking for this species for a while so this was a nice find. Of the ten or so we found, one was infested with the parasitoid braconid wasp cocoons. See photos below.

When Splitting is a Good Thing (Spiranthes niklasii)

Anyone who has hung around biologists and naturalists long enough has surely heard the complaints of how taxonomists are going too far in their evil over-splitting ways. Their notion being that phylogenies painstakingly developed via decades of phenotypic comparisons should not be overturned by a few afternoons of running gels in a lab. I’m sure most of us can point to a convincing example of over-splitting amongst our favorite groups of organisms, but I hope that the subject that I am featuring tonight will give you pause before reaching for that familiar defense and realize there are circumstances where a group benefits from a fine dissection when the appropriate tools are available.

A great example of a group that has benefited from a well-executed genetic taxonomic treatment is the Spiranthes cernua species complex of the “ladies tresses” orchids. This species complex has long been known for cryptic species with curious cases of plants being plants – exhibiting hybridism, polyploidy (having more than two sets of chromosomes) and apomixis (reproduction without fertilization). The species, Spiranthes cernua, which is found in Missouri, has been problematic and considered as a polyphyletic taxa (derived from two or more distinct ancestral taxa). In attempting to shed light on the phylogenetics of this species complex, Mathew Pace and Kenneth Cameron have published a fantastic treatment in which they attempt at “Untangling the Gordian Knot”. Most of what I write here is paraphrased from their paper cited at the end of this post.

Spiranthes niklasii – an ancient case of kissing cousins in the Ouachita Mountains.

A common method of speciation in plants is interspecific hybridization. Pace and Cameron identified three instances of ancient hybrid speciation involving S. cernua. One of these circumstances that has now been given specific status is Spiranthes niklasii. This species is near-endemic to the Ouachita Mountains of Arkansas and is likely a result of a proposed ancient hybridization event between Spiranthes cernua and Spiranthes ovalis.

Pace and Cameron describe S. niklasii as being quite similar in appearance to S. cernua, but can be distinguished by “a central ridge of small papillae on the adaxial surface of the labellum, more strongly campanulate flowers, and usual preference for a more xeric habitat.” When I read this and found out we had an opportunity to see this species, I knew I wanted to try and capture those papillae in a photograph. We found this species in bloom in Saline and Pulaski Counties in Arkansas on 10, October, 2021. While my photos cannot do justice to the excellent figures found in the above mentioned work, I was still thrilled to be able to capture these minute structures while on a camping trip in the Ouachitas.

The ridge of papillae on the labellum of this flower, as seen above, is a diagnostic trait of Spiranthes niklasii.

By the way, one of the other cases of hybrid speciation involving S. cernua that was identified by Pace and Cameron has further implications on my work. Spiranthes incurva is a newly described species that is hypothesized to be the result of an ancient hybridization between Spiranthes cernua and Spiranthes magnicamporum. In Missouri, the result of this split is that S. incurva now lies roughly above the Missouri River while S. cernua is found south of the river. This means that I now have added another species to my orchids of Missouri. A new orchid for me to photograph!

I would like to thank Casey Galvin and Eric Hunt for helping me find these plants.

Literature Cited

Pace, Mathew C., and Cameron, Kenneth M. 2017. The systematics of Spiranthes cernua species complex (Orchidaceae): Untangling the Gordian Knot. Systematic Botany. 42(4): pp. 1-30

Until next time,
-Ozark Bill

Parasitoid Cocoon

We found this cocoon of a parasitoid wasp (Ichneumonidae) during a WGNSS Nature Photo Group Outing in September of last year. This distinctive cocoon is identified to belong to a member of the subfamily Campopleginae who are characterized as koinobiont (allows host to continue development) endoparasitoids that primarily parasitize lepidopteran hosts. We did not find any remains of a potential host nearby.

Campopleginae cocoon

Crystallofolia – A Return To Missouri’s Autumn “Frost Flowers”

I first posted about frost flowers a little more than ten years ago on this blog. This season, after learning about the two plants that are most likely to form them in our geography and having the flexibility to be on location at the specific times they are capable of forming, I was able to take advantage and take my time in capturing them with the camera.

The first gallery are the more robust of the crystallofolia. Dave and I stumbled across these in Madison County, MO. These are formed on the dying stalks of Verbesina virginica (F. Asteraceae), aptly named “frostweed” or white crownbeard. This is the more robust plant of the two featured here and, consequently, forms larger and more robust frost flowers. Some of these were up to 12″ in height.

A note about how crystallofolia form.
Because these later-maturing species are still somewhat viable during the first deep freeze, the xylem pathways responsible for moving water from the roots to the shoots are still functional. The roots in the still unfrozen soils are pushing water to the shoot of the plant via capillary action. On the first few nights when temperatures drop to the mid 20 degrees F, the water in the shoot freezes, bursting the sides of the stem pushing the freezing water out and forms these gorgeous petals. If you look closely, you can see the individual “tubes” of ice that make up the petals of the frost flowers. These tubes correspond directly to the xylem rays – the tubes that distribute water from the vertical rising xylem to the outer tissues of the plant. Another interesting thing about these structures is that they will often dissipate through sublimation. The super cold and dry conditions can cause these thin and delicate petals to evaporate directly to gas, skipping the liquid water phase.

The second species featured here were found in Jefferson County, MO on a trail. Earlier in the season I had noted the abundance of dittany (Cunila origanoides) F. Lamiaceae. This species is smaller and forms dainty frost flowers, mostly no more than four inches in height. They can also be much more elaborate than the frost flowers formed by V. virginica, with long, curling petals that have a tendency to curl back on themselves.