Cardinal-flower, and the coming floral hiatus

A brilliantly hued Cardinal-flower (Lobelia cardinalis), shot back on August 25, 2023. A floral hiatus now ensues, until the blooming of Skunk-cabbage at winter's end, at least in my part of the world. It got down to 29F last night, here in Worthington, Ohio. This Cardinal-flower was photographed in Scioto County, Ohio.

Photographic Note: Reds in flowers can be tricky to expose properly (as can yellow). It's easy to overexpose them, and thus wash out the gorgeous hues that make red flowers so fetching. Depending on the conditions, I often underexpose a bit, maybe 1/3rd stop, sometimes more. Wind is also not the flower photographer's friend, and as I recall this was a mostly windless day. Thus, I shot from a tripod with a 2-second timer delay (so I am not touching and possible moving the camera at the time of exposure). I also have the camera (Canon R5) set to touch screen focus. I just touch the spot that I want to have as the focus point on the camera's back screen, and Voila! Two seconds later the camera fires, focused on the exact spot that I touched. I'm also partial to very open apertures when I feel that I can get away with them, as f/4 (in this case) creates such a beautifully blurred background (bokeh). f/4 to f/7.1 are favored flower apertures although I will frequently venture off that reservation. ISO, of course, is set very low - 200 in this case. For floral photography, shutter speed is largely irrelevant to me, especially if there is not movement on the subject's part. This image was shot at 1/25 but I have often shot flowers at speeds as low as several seconds.
 

Ruby-throated Hummingbird pollinates Cardinal-flower

I made an epic foray into southern Ohio's Shawnee State Forest back on August 1, and had several photographic goals in addition to shooting whatever I might bumble into. One of these goals was to photograph a ruby-throated hummingbird in the act of pollinating a plant that the little birds are especially smitten with. Some success was had, and the story plays out below.

Cardinal-flower, Lobelia cardinalis, one of our showiest native plants. It seems fitting that such a gorgeous plant would have an interesting pollination ecology that involves one of our most charismatic birds.

The flowers on this spike are young, and mostly staminate (male) at this point. The arcuate grayish projection from the summit of the flower contains the sexual parts, and when the flowers are new they extend a brushlike clump of stamens capped by the anthers which contain pollen.

This is a different cardinal-flower in the same colony, but the flowers are older and have progressed to putting forth largely female organs. The stubby grayish protrusions are now mostly capped with longer extensions that contain the stigma, or female pollen receptacle. The male anthers have done their work regarding pollen dispersal, and been replaced by the opposite sex.

One must exercise some patience when trying for shots such as these. I found a few particularly stately cardinal-flower spikes, rigged up my tripod-mounted Canon 5D IV with 400mm lens, and 600 speedlite, then settled into a three-legged camo chair to await my quarry. As it happened, I did not have to wait long before a female ruby-throated hummingbird appeared. After making these images, I disassembled my big rig and went back with a wide-angle lens for general flower shots. While doing that, this tiny but fearless hummer returned and began working flowers within a few feet of where I knelt.

The hummers routinely visit cardinal-flowers, which apparently are prolific nectar-makers. The nectaries are deep within the corolla, forcing the bird to plunge its bill far into the flower. In the process, the top of its head makes contact with the downward-curving sexual flower parts. If the flower is in the male phase, pollen will be deposited on the hummingbird. If in the female phase, pollen from some other flower - hopefully from another plant - will transfer from the bird's head to the stigma, and thus pollinate the flower and allow production of fruit.

A closer view, showing the flower's stigma scraping the top of the hummingbird's head. It'd be virtually impossible for the bird to access its reward - the nectar - without coming forcefully into contact with the flower's reproductive parts.
 

While hummingbirds certainly must be the primary pollinator of cardinal-flower, as is often said, I believe that swallowtail butterflies, especially spicebush swallowtail, Papilio troilus, must at least occasionally provide pollination services. This is a spicebush swallowtail working the same patch that the hummingbird above frequented. Swallowtails swarm blooming cardinal-flowers and at times there were a dozen or more mobbing these flowers. While the butterfly/flower dynamic is not as well architected as the hummingbird/flower arrangement, I bet pollen still gets transferred between both flower forms.

The coevolution of cardinal-flower and hummingbirds is a particularly showy example of the myriad ways in which plants have forged alliances with animals.

Cardinal-flower, rare in white, and pollinating swallowtails

The brilliant red flowers of Cardinal-flower, Lobelia cardinalis, form a conspicuous spike that just can't be missed. This is one of the flashiest plants of late summer and fall. I've seen plants that regularly attain heights of four feet, and the occasional giant that towers to over six feet. Its favored haunts are the rich alluvial soils of floodplain terraces, sometimes in fairly heavy shade but usually doing best where much sunlight reaches the plants for a good chunk of the day.

Even more interesting than the typical rich red form of Cardinal-flower is the far scarcer white-flowered type, which has been described as forma alba. I've only seen this variant in nature a handful of times, so when Dave Riepenhoff tipped me to a colony in Scioto County, Ohio, I was pleased indeed, especially as I had a trip planned to that area a few days later.

It wasn't hard to spot the plants. I rounded a slight bend in the road, which followed a small creek, and saw dozens of typical red-flowered plants. Not far behind were a dozen or so magnificent white-form plants, and they fairly glowed in their shady haunts. Above, one of the white plants grows side by side with a typically colored form for ease of comparison.

Here's the colony, with the tallest white-flowered plant reaching nearly four feet in height. Quite a striking sight. Stretching for perhaps a few hundred feet down the creek were dozens of other plants, all of those the typical red-flowered form.

It is often said that Ruby-throated Hummingbirds are the primary pollinators of Cardinal-flower, and some sources even claim it is the only pollinator. The elfin birds do indeed thirst for this species' nectar, and I've seen them visit the flowers many times. Indeed, that's why I arrived at this spot very early in the morning, and set up photographic shop - my aim was to create high-quality images of hummingbirds visiting the flowers, especially those of the rare white form.

Well, there were indeed some hummingbirds about, but they only occasionally visited the Cardinal-flowers and never did come into the white-flowered plants which I set up on. They seemed far more smitten with the numerous Spotted Jewelweed, Impatiens capensis, another wildflower which is coveted by the little birds. In fact, there was a huge patch of the stuff right behind my position, and a male Ruby-throat was guarding it fiercely. He'd drop down and feed at the flowers for a few minutes, then zoom back up to a conspicuous perch overlooking his kingdom, only 15 feet behind my head. Any other hummers that came near were promptly driven away.

As the air warmed, the swallowtails became active and eventually stole the show. At times, fifty or more were mobbing the Cardinal-flowers and three or four often sparred over the same plant, as in the photo above. These big butterflies quickly became my focus.

Virtually all of the butterflies were Spicebush Swallowtails, Papilio troilus, as above. I did see one or a few dark morph Eastern Tiger Swallowtails and Pipevine Swallowtails visit the flowers, but the overwhelming majority were the spicebushes. Interesting, even though plenty were about, I never saw a yellow form female Eastern Tiger Swallowtail or any of the always yellow males make an effort to visit the Cardinal-flowers. They stayed strictly with plants in the aster family, most notably Hollow-stemmed Joe-pye, Eutrochium fistulosum.

PHOTOGRAPHIC NOTE: Nearly all of these photos were made with the Canon 5D IV and Canon's superb 500mm f/4 II telephoto lens, mounted on a tripod. Big butterflies such as these really transcend macrophotography, and are easier to shoot from afar with a telephoto. This allows the photographer to remain far enough back to be completely unimportant to the insects, which will operate free of disturbance and as they naturally would. Most any lens of 300mm and up should work very well for swallowtail photography.

A Spicebush Swallowtail plunges face deep into the sweet spot of a Cardinal-flower. As I was observing and photographing the butterflies, I was thinking about the claims for hummingbird pollination exclusivity. It doesn't make sense that a plant such as this would evolve flowers that are so attractive to butterflies that they would be continually swarmed by the insects, and not derive much if any benefit in return.

Indeed, the flowers appear tailor-made for swallowtail access. The three lower petals hang down, offering a convenient perch for butterflies wishing to plumb the nectaries at the base of the long corolla tube. This arrangement puts the head of the insect in close proximity to the flower's reproductive parts, which are the grayish-white extensions at the top of each flower. When a flower is young, the reproductive extension is a brush or beard-like spur that contains the anthers, which hold the pollen. As the flower matures, the female stigma becomes exserted from the corolla tube - a stigma can be seen protruding from the flower directly opposite the butterfly.

So, the end game for the plant is to have an animal vector move pollen from anthers to stigma. As colonies of Cardinal-flowers, and even individual plants, will have a combination of flowers with exposed stamens/anthers and stigmas at any given time, flower-hugging butterflies would certainly seem capable of accomplishing this task.

In this shot, we can see a swallowtail's head jammed right into a brush of anthers, and it certainly must be receiving a dusting of pollen for its transgressions. All the butterfly need do is eventually work its way to an older flower with an exposed stigma while some of those pollen grains remain stuck to its head, and Voila! Pollination.

So, while hummingbirds are no doubt important pollinators of Cardinal-flower, I think a strong case can be made that swallowtail butterflies are also important to the gorgeous plant's reproduction. Maybe even more so than the bird.

A white Cardinal-flower

Photo: Bill Fisher

Bill Fisher, Director of the Crawford County Park District, sent along a photo that really grabbed my eye. It is a snow white Cardinal-flower, Lobelia cardinalis, and as can be seen by its normally colored cohorts, this is atypical. Bill made the photo a day or two ago at their Lowe-Volk Park, where it is growing in the "pollination station".

If you're in the area, stop in and see it. Might be a while before you see another. I can't tell you how many hundreds or thousands of these plants that I've seen over the years, but never a white one that I can recall. Such a form is rare, but occurs with enough regularity to have an official designation: Lobelia cardinalis forma alba. It'll be interesting to see if white ones pop up in this patch in future years.

Cardinal-flower

Perhaps the most striking shade of red in nature; the blossoms of cardinal-flower, Lobelia cardinalis. It is also a favorite nectar source of Ruby-throated Hummingbirds. This specimen was photographed along a small stream in Scioto County, Ohio last Saturday.

Botanical eye candy

We encountered this mammoth cardinal-flower, Lobelia cardinalis, yesterday. It was growing in the rich alluvium of a remote Hocking County stream, and the tall spikes of scarlet flowers glowed luminescent in the dim light of this heavily forested stream valley. The plant was well over six feet in height, and the central spire seemed to shoot skyward  from a fireworks display of lesser flowers.

Needless to say, this robust plant was worthy of some clicks of the camera, and I delayed long enough to make some images. Cardinal-flower can be surprisingly hard to shoot well. The brilliant flowers often appear washed out and lifeless in photos.

One trick is to make sure that the backdrop will adequately showcase the plant's colors. Plenty of green in the background seems to do the trick. It also helps to use a larger aperture to reduce depth of field and fuzz out all but the flowers.

Finally, my efforts are better if I intentionally underexpose the image, and allow a very soft flash to compensate.

It's a shame to see such a work of art as this cardinal-flower, and return home with less than satisfactory images.

Two summer jewels

I spent a long weekend in southern West Virginia, visiting some of my favorite places. This is the region where the New River Birding and Nature Festival takes place every year. I made a series of posts about this spring's festival, starting HERE. I understand people are already signing on for next spring's event, so get in early. That festival takes place at the peak of spring, but they could just as easily put one on in mid-summer. I was able to find many birds still singing, and the plants - and various bugs - are outrageous.

A robust Cardinal-flower, Lobelia cardinalis, grows in a damp roadside swale near Babcock State Park. There were many plants, and the swallowtails - Pipevines and Eastern Tigers - were swarming the plants.

A beautiful and relatively easily grown native plant. Not only is Cardinal-flower electric red, it has the added appeal of being a butterfly magnet.

I've found Cardinal-flower to be a surprisingly hard plant to take a great photo of. Not just good, I mean great. Something about the brilliant shade of red causes the flowers to completely wash out in bright sunlight, which were the conditions that I found it in today. If not in full sun, it'll be in shade or worse yet, dappled shade. Anyway, the shots above were taken with manual exposure and were intentionally underexposed to keep the color from looking washed out.

Directly across the road were a number of Turk's-cap Lilies, Lilium superbum, easily at or near the top of the list of North America's most striking lilies. I was excited to see them, as I didn't know there were Turk's-caps in this area. The above plant was so tall that it was groaning under its weight and listing hard to the side. The luxuriant stand of Cinnamon Ferns, Osmunda cinnamomea, make a nice backdrop.

A robust Turk's-cap Lily can tower to eight feet or more in height, and be crowned with a half-dozen plus flowers.

The rich orange flowers are a work of art, and reminded the namer of a Turkish turban. The scientific epithet, superbum, means just that - SUPERB.

The only species that resembles Turk's-cap Lily in these parts is Michigan Lily, L. michiganense, which is easily ruled out where I was as it doesn't occur in West Virginia. A bit tougher to separate is the southern Michaux's Lily, L. michauxii, which is in southernmost WV. It has differently shaped leaves, though.

Turk's-cap Lily is a total showstopper, and it was great to see it. But I saw much more, and I'll try and slap some other West Virginia goodies up here soon.