The Monthly Orchid: What do get when you cross a Coralroot & a wasp?

Answer: Capsules filled with seeds! (Striped Coralroot, Awinch1001)

Welcome back to the The Monthly Orchid, a series about South Dakota's native orchids. This month we again look at Coralroots, specifically the Striped Coralroot, Corallorhiza striata. Coralroots aren't particularly showy, but this one is a bit of an exception. Though the lip petal is small, its stripes are bold. Might they have a purpose? To this, Charles Darwin would reply with an emphatic "Yes!"

Corallorhiza striata; note yellow pollen positioned above base of lip (Freudenstein & Barrett 2026).

Darwin was fascinated by orchid flowers, largely because "the contrivances by which Orchids are fertilised are as varied and almost as perfect as any of the most beautiful adaptations in the animal kingdom." In this diversity, he saw an opportunity to respond to criticism of On the Origin of Species, which he published in 1859.

Just a few years later, Darwin finished another book—The Various Contrivances by which Orchids are Fertilised (1862). In the Introduction, he explained the purpose of his "little treatise" (c. 300 pages):

"Having been blamed for propounding [natural selection] without giving ample facts, for which I had not sufficient space in that work, I wish here to show that I have not spoken without having gone into details."

A myth Darwin intended to debunk was the notion that orchid beauty is "the result of the direct interposition of the Creator" for the pleasure of humans. Wrong! Beautiful orchid flowers are the result of natural selection, and like the vast majority of flowers, they have one purpose—continuation of the species, via sex. 

Why such varied and gorgeous lips? From Kunstformen der Natur, E. Haeckel, 1899.

In last month's post, a Coralroot seed encountered just the right underground fungus, germinated, started to grow, and emerged from the Underworld. We left it surviving on carbon captured by trees and shared (involuntarily) by the fungus. What next? At some point we should see buds, followed by flowers, and then capsules with seeds. Must the fungus help with all this as well? Aside from providing sustenance for growth, the answer is "No". In the case of the Striped Coralroot, however, dependency continues. Now another type of creature will be will be duped.

For most flowing plants (angiosperms), pollination is required to produce seeds. This is what drove evolution of the astonishing diversity in orchid flowers.

South Dakota orchids: Helleborine, Yellow Lady's Slipper, Prairie Fringed Orchid; note the varied contrivances.

With many examples (1), detailed descriptions and lengthy discussion, Darwin was able to argue convincingly that most orchids are designed with insects in mind.

"these contrivances have for their main object the fertilisation of the flowers with pollen brought by insects ... In almost all the species, one of the petals, which is the properly upper one, is larger than the others and stands on the lower side of the flower, where it offers a landing-place for insects, having been carried round by the twisting of the ovarium (2). It is called the lower lip or labellum, and often assumes most singular shapes." (italics mine)

In addition to specialized lips, orchids employ a variety of strategies to lure pollinators (Ackerman et al. 2023; Wikipedia). The most common is attraction by means of reward, e.g., nectar, oil, perfumes. These are given in exchange for pollen transport—arrival from or delivery to another orchid of the same kind. Flower shape, color pattern, and scent are commonly used to attract a specific pollinator, reducing the chance that pollen is wasted on the wrong orchid. 

But many orchids are not so nice. At least a third of the 30,000 known species rely on deception to attract pollinators. Having become highly specialized through natural selection, they are very good at this. Here are some examples.

• An orchid that provides no nourishment has flowers very similar to those of a plant that does. This is feeding deception, the most common type of deceptive pollination. 

• In brood-site deception, an orchid's flowers look like perfect egg-laying sites to the pollinator (see next photo). 

• Even more remarkable is pseudo-antagonism, in which a flower mimics an enemy of the pollinator, invoking an attack during which pollen is transferred!

Cypripedium lichiangense, the Lijiang Cypripedium (Steve Garvie). It offers an appealing (stinky!) but fake brood-site for Ferdinandea cuprea, a hoverfly (Ackerman 2023).

The most fascinating strategy (based on number of studies and websites) appears to be sexual deception, or pseudocopulation. It's the second most common type of deceptive pollination in orchids, documented in at least 22 genera (Ackerman 2023). Perhaps you have already guessed—Striped Coralroot is a sexually deceptive orchid! In fact, it's the first example of a pseudocopulatory orchid from North America!! (Freudenstein & Barrett 2026)

Corallorhiza striata, Andrey Zharkikh.

Freudenstein and Barrett used an insect net to capture wasps visiting Striped Coralroot flowers. They sexed them by looking for a prominent ovipositor. All 28 were male. Another 13 males were captured and sexed in photographs. The researchers then probed 30 of the flowers visited, and found no nectar. 

To determine what was attracting the wasps, they opened a plastic bag of Striped Coralroot flowers inside a net cone, hoping to release volatile scent compounds. Sure enough, within two minutes a swarm of 10 wasps appeared, flew around the cone, and landed on it (they couldn't get to the flowers).

And the stripes? The authors found no obvious resemblance between flowers and female wasps, but the "red stripe down the center [of the lip] flanked by two lighter patches could signal a wasp metasoma" (a body segment). I wonder—how might one test this hypothesis?

Whatever the attraction, all visiting wasps were the same kind—Pimpla pedalis, which is parasitic on the Pale-Winged Gray, a moth that defoliates Eastern Hemlock. In other words, the orchid dupes a wasp that is parasitic on the larvae of a moth that harms trees. Go Coralroot! (3)

If you are unable to view Pimpla pedalis "mating" with Corallorhiza striata (above), go to Freudenstein & Barrett 2026 (open access) and download the video in Supporting Information at the bottom of the page. Or try this video narrated by David Attenborough. It includes neither Striped Coralroot nor Pimpla pedalis, but is quite entertaining!

Now it's time to leave the Coralroots and move on to orchids with morals as well as beauty, perhaps Cypripedium (Lady's Slippers).

"As Orchids are universally acknowledged to rank amongst the most singular and most modified forms in the vegetable kingdom ... examination of their many beautiful contrivances will exalt the whole vegetable kingdom in most persons' estimation." (Darwin 1862, italics mine)

Cypripedium (Darwin 1862).

Notes

(1) Darwin's book includes exotic as well as British orchids. He received many specimens after reaching out to colleagues and collectors.

(2) Darwin is referring to resupination, which is common in orchid flowers. In bud, the lip petal is oriented upward, but by the time the flower opens, the ovary (sometimes the flower stalk) has twisted enough to orient the lip downward. See The Upside Down World of Orchids.

(3) In the orchid's ruse, Freudenstein and Barrett saw the opportunity for an especially alluring title: "Corallorhiza striata is the first example of a pseudocopulatory orchid in North America and an instance of 'double deception' in fully mycoheterotrophic plants." Wow, that's so cool! But wait ... is this really double deception? That depends on your opinion of Coralroots after reading last month's post.


Sources (in addition to links in post)

Ackerman, JD, et al. 2023. Beyond the various contrivances by which orchids are pollinated: global patterns in orchid pollination biology. Botanical Journal of the Linnean Society 202:295–324. https://doi.org/10.1093/botlinnean/boac082 

Britannica. Orchid/natural history/pollination. Accessed August 2026.

Darwin, Charles. 1862 (1904, 7th printing of 2nd edition). The Various Contrivances by Which Orchids Are Fertilised by Insects. London: J. Murray. https://doi.org/10.5962/bhl.title.84436

Freudenstein, JV, and Barrett, CF. 2026. Corallorhiza striata is the first example of a pseudocopulatory orchid in North America and an instance of“double deception” in fully mycoheterotrophic plants. American Journal of Botany 113(4): e70185. https://doi.org/10.1002/ajb2.70185

USDA Forest Service. Coralroot Orchids. The Celebrating Wildflowers—Beauty of It All website is a joy to wander through! I wish I knew whom to credit for it.

Back to Lake Lahontan, with a guy who knows it well

Lake Lahontan (pale gray) is "a large lake which flooded a number of the valleys of northwestern Nevada at a very recent geological date, but now has passed away."

Last May, I visited Lake Lahontan in the company of pioneering geologist Israel Charles Russell. Of course neither was physically present. The lake passed away c. 10,000 years ago, and Russell died in 1906. But Lahontan left behind abundant relics—sediments, shorelines, gravel bars, tufa deposits and more. Guided by Russell's spirit, I was able to "restore in fancy" landscapes very different from today's high desert (quotes are Russell's words unless noted otherwise).

Today's northwest Nevada is a harsh and arid land. "The mountains are rugged and angular, usually unclothed by vegetation. The valleys, even more dreary than the mountains ... form a picture of desolation and solitude." But just 13,000 years ago the basins were flooded, forming "a single irregular water-body" with islands and peninsulas that "bristled with barren and rugged mountain ranges".

Northwest Nevada today. Google Earth, 2021.

Northwest Nevada 13,000 years ago (Matthew Trump).

Israel Russell and I met two years ago in the Mono Basin, in eastern California. He had worked there in the mid 1880s as a geologist with the US Geological Survey. His Quaternary History of the Mono Valley was published as part of the Survey's annual report in 1889.

As well as explaining geology, Russell described with great enthusiasm the beauty, drama and novelty of the landscapes. Citizens of the tiny town of Lee Vining were so taken by his prose that they requested an independent printing of Quaternary History from the USGS, which they would use to entice tourists. It was reprinted in 1984, by Artemisia Press of Lee Vining (still a small town). I found a used copy online.

With Russell's report in hand, I toured volcanoes, relic terraces, glacial features, and Mono Lake—a little lake with no outlet and water so alkaline that one can float on the surface. But it was very different during ice age times, as Russell explained—"a nearly unbroken water surface 28 miles long by 18 miles broad" fed by glacial meltwater, and overflowing to the north. He called it "Lake Mono" to distinguish it from today's relic. Fifty years later it was christened "Lake Russell", a fitting tribute (Putnam 1949).

Lake Mono (now Lake Russell) back when Sierra Nevada glaciers reached the basin (Russell 1889).

About a year ago, I briefly visited the remains of another ice age lake nearby, one contemporaneous with Lake Russell but much larger—Lake Lahontan. When I learned that Russell had studied it too, I immediately made plans to return. From a rare book store, I ordered his monumental Geological History of Lake Lahontan. His words added much to the landscapes I saw—details, highlights, understanding, appreciation.

Russell did not discover Lake Lahontan, nor did he name it. The first to allude to it in a publication may have been John C. Fremont, who crossed this way in 1843 and 1844, and described tufa in his report. But as Russell later wrote,

"... although [Fremont] noted the presence of tufa deposits about Pyramid Lake, and published a sketch of the tufa-coated island ... he does not seem to have recognized that his route led through the desiccated bed of an ancient inland sea."

"Like other rocks along the shore, [the pyramid] seemed to be incrusted with calcareous cement" (Fremont 1845).

Fifteen years later, geologist Henry Engelmann with the 1859 Simpson Expedition very much recognized the ancient inland seas they crossed:

"That the country adjoining Salt Lake and Carson Lake has once been covered with water must strike every observer ... regular 'benches' of shingle and detritus have been formed along the surrounding heights ... They frequently appear as distinct water-marks of equal height all around" (Engelmann 1876; italics mine).

Fort Churchill State Park; note terraces on slope on left—Engelmann's "distinct watermarks".

The first detailed geological study of  Lake Lahontan was done in 1867, by Clarence King, Arnold Hague and SF Emmons as part of the "Geological Exploration of the Fortieth Parallel". It was King who named the "great extinct sheet of water" in honor of Baron de LaHontan, the "gallant French explorer" of the Mississippi headwaters in the late 1600s. However, King's survey was limited to a belt 100 miles wide, leaving large areas of Lahontan to the north and south needing survey and study.

By 1880, King had become Director of the new US Geological Survey, and Grove Karl Gilbert, head of the Great Basin division, had begun his survey of ice age Lake Bonneville in Utah. There he was assisted by a recent hire—Israel Russell. Gilbert was so impressed with Russell's skills and motivation that he gave him his own project—Lake Lahontan in Nevada. In three fields seasons Russell would study and map the entire basin, more than 20,000 square miles, becoming "the first to read [Lahontan's] story, trace its history, and recognize the numerous agencies that varied its life and led to its death."

"Routes traveled [red & pale blue lines] and areas surveyed" (Russell 1885).

Russell started with a solo reconnaissance in 1881. It lasted seven months "during which about 3500 miles were traversed in the saddle." Having crossed the ancient lake multiple times in various directions, Russell was able to decipher much of its history. Details were added during the field seasons that followed, through observation and instrumental work with the help of a topographer and two geological aids. Their studies were extensive, thorough and diverse.

They delineated, measured and made detailed drawings of lakebed sediments. They mapped topography, paying special attention to the geometry of basins flooded by Lahontan's waters. They sampled today's lakes to determine their chemistry and origins. When opportune, they collected fossils and the three types of tufa: lithoid, thinolitic and dendritic. And they measured, mapped, sketched and interpreted relic features left by the ancient lake—beaches, shorelines, gravel bars, spits and more. My hope was to stand where they had stood and see what they had seen, while imagining the waters of an immense lake sparkling in the sun.

See the sparkling lake?

The northeast part of Lake Lahontan lies due west of Laramie, a 770-mile drive on Interstate Highway 80. My first stop was Rye Patch, on the Humboldt River.

"the Humboldt River flows in a channel that it has excavated in Lahontan sediments since the last desiccation of the ancient lake. ... at Rye Patch the river flows a little more than two hundred feet below the general level of the desert. ... Throughout this portion of the cañon the tripartite division of the strata exposed in the steep banks is easily distinguished."

"Lahontan sediments, Humboldt Cañon, near Rye Patch, Nevada" (Russell 1885).

The Humboldt River at Rye Patch was dammed in 1936, but the reservoir was quite low when I visited. From the campground, I viewed Lahontan sediments in the canyon walls just above the water, with a typical "angular unclothed" range rising above.

Lahontan sediments, Humboldt Cañon, near Rye Patch, Nevada, 2026.

I saw what looked like the "tripartate division" described by Russell (click on image above): pale clays at the base, which settled when the lake was deep; then a darker bed of gravel washed in when the lake was shallow and much smaller; and on top, more clays when it again filled. These three layers were important evidence for Russell's conclusion that "two high-water stages [were] separated by a time of desiccation" (still widely accepted).

Detailed section showing Lahontan sediments near Rye Patch (Russell 1885).

The next day I awoke to rain. So I toured Lake Lahontan by van searching for relic features. From Rye Patch I drove west and then south on I-80, following the Humboldt River to where it ceases to exist, the last of its trickles having sunk into the Carson Desert (as do the Carson and Truckee Rivers nearby).

I drove for miles across "broad silent plains of desolation" while thinking of Russell and his crew working in the heat of summer, without shade, and with no water except for the rare pool in a playa. That was too alkaline to drink of course, but as their tests showed, it also was too fresh—not salty enough to be the last remnants of Lahontan. The great lake must have evaporated entirely.

Humboldt Lake in Humboldt Sink (Famartin, arrow added).

Playa up close: "tessellated pavements of cream-colored marble"

When the rain let up, I decided to look at gravel. Being a highly irregular lake occupying multiple basins connected by narrow straits, Lahontan left behind a lot!

"Accumulations of gravel in the form of bars and embankments occur at many points along the ancient shores ... These are seldom straight, but curve with beautiful symmetry, each gracefully bending ridge marking the course of a current in the waters of the ancient lake in which it was formed."

Out of convenience, I stopped at a quarry. No gracefully bending ridges were visible, but I enjoyed wandering around and contemplating the handiwork of Lahontan's currents. And the size of the deposit was astonishing!

Gravel quarry below Mopung Hills, east of Carson Sink.

Immense gravel bar, shaped by quarrying.

The next day I awoke to sunshine, and again departed Rye Patch on I-80. After crossing the subtle divide between Humboldt and Carson Sinks, I turned south on US Highway 95. My destination was Russell Pass on the shore of Lake Lahontan, at the south end of the Carson Basin. It's clearly marked in Roadside Geology of Nevada (DeCourten & Biggar 2017) and on the local USGS topographic map. There I would commune with Russell's spirit and view the lake phenomena he described.

About 18 miles south of Fallon, a notch came into view. Everything looked right—bold rugged volcanic rocks, some encrusted with tufa, and slopes girdled with terraces. But at the pass was an unexpected sign, and no place to pull off.

"ENTERING Gabbs Valley Watershed"

I continued south a short distance to the Russell Pass Landfill, where I checked several maps. Indeed, Russell Pass is on the divide between the Carson and Gabbs Watersheds. Confident I had visited Russell Pass, I turned around and began my search for Russell Spit.

When Lake Lahontan was full, the pass and adjacent highlands were an island. On one side was a narrow strait "through which the currents must have swept with great force" given the impressive group of gravel bars and spits that formed.

"Gravel embankments on south border of the Carson Desert, Nevada" [arrow mine].

Plate XIX above, by topographer WD Johnson, was one of the more exceptional illustrations in Russell's Monograph. Roger Morrison included it verbatim in his report on the southern Carson Desert (1964). By that time, the gracefully curving gravel bar (white arrow) east of the large playa was known as "Russell Spit" but exactly when the pass and spit were named appears to be lost (I'm still searching). It must have been before 1951, when the Russell Spit 7.5' topographic map was first published.

From the highway, I turned off at a sign for the Top Gun Drag Strip, where races were underway (audibly obvious). On excellent gravel roads I explored as far south as a huge gravel quarry, where I concluded I didn't know what to look for. Or could Russell Spit be gone? I turned around.

Volcanic rock and tufa, with gravel everywhere.

I stopped to examine pinnacles of volcanic rock and large blobs of tufa. Based on what I read and saw in the Monograph, it looked like dendritic tufa, "by far the most abundant of all the chemical deposits of Lake Lahontan."

"Dendritic tufa deposited on a cliff" (Russell 1885).

Dendritic tufa near Russell Pass, 2026.

Then I looked east across the highway and spotted the terraces Russell saw when he was here, horizontally scored in soft volcanic rock.

Ancient shorelines—"the most common of the records inscribed".

With that, my search for Russell Spit came to an end—unfulfilled perhaps, but hardly disappointing. I had stood where Russell stood, experienced the gravel he had experienced, gazed on tufa-coated volcanic rocks and wave-cut terraces as he had, all the while "restoring in fancy" Lake Lahontan sparkling in the sun.

Sources

David Rumsey Map Collection. Geological History of Lake Lahontan, maps and illustrations.

DeCourten, F, and Biggar, N. 2017. Roadside Geology of Nevada. Mountain Press.

Engelmann, H. 1876. Geological report of country from Fort Leavenworth to the Sierra Nevada, pages 247–336 in Simpson, JH, et al. Report of explorations across the Great Basin of the territory of Utah : for a direct wagon-route from Camp Floyd to Genoa in Carson Valley in 1859. BHL

Fremont, JC. 1845. Report of the exploring expedition to the Rocky Mountains in the year 1842, and to Oregon and north California in the years 1843-'44. Internet Archive

Morrison, RB. 1964. Lake Lahontan: geology of southern Carson Desert, Nevada. USGS Prof. Paper 401.

Putnam, WC. 1949. Quaternary geology of the June Lake District, California. GSA Bull. 60:1281–1302.

Russell, IC. 1885. Geological history of Lake Lahontan. USGS Monograph 11.

Russell, IC. 1889. Quaternary History of the Mono Valley, California. Internet Archive

The Monthly Orchid: Coralroots—parasitic cheats or just slackers?

I walked right by these Coralroots! Fortunately I returned the same way and saw them.

Welcome to the The Monthly Orchid, a series of blog posts about South Dakota orchids. This one features Coralroots, genus Coralloriza—small inconspicuous plants but surprising or even shocking in their ways. After considering their manner of living, you can share your opinion of them in a Comment.

Five Coralroot species grow in South Dakota, all in the Black Hills. But the rest of the state is not nearly as well botanized as the Hills, and these little orchids may be lurking in shady hardwood forests far to the east. I wouldn't be surprised; four of our species occur nearby in Minnesota.

Coralroots are short, slender, drab, and easily overlooked. Stems come in a range of muted colors—red, brown, purple, yellow, occasionally greenish. Color can vary widely among populations of a single species, based on genetics and environmental factors, for example soil acidity.

Kneeling on the forest floor, we see a Coralroot's subtle beauty (Corallorhiza maculata).

Corallorhiza maculata, yellow population (USDA Forest Service).

Yellow Coralroots (Corallorhiza trifida) may be nearly green; but whether they can photosynthesize isn't clear (USDA Forest Service).

Like most orchids, a Coralroot begins life as a seed the size of a speck of dust, housed in a capsule with many thousands of its siblings. When the capsule dries and splits, the seeds are cast to the wind. Being so tiny, orchid seeds have NO endosperm—none of the nutritive tissue that most angiosperms (flowering plants) provide their embryos. So to germinate successfully, they must find help.

With luck, a Coralroot seed lands on a shady moist site with a network of fungal tissue (a mycelium) on or near the soil surface. If the fungus is the right kind—one that can form partnerships with plants (mycorrhizae)—there's a chance that germination will succeed.

Fungal mycelium—a network of hyphae that delivers water and nutrients to whatever is connected to it (Kirill Ignatyev).

When the seed germinates, the tiny embryo develops into a protocorm—a mass of cells less than a millimeter tall just beginning to differentiate. The basal cells allow a strand of fungal tissue to enter, but keep it from spreading further. This is the connection that will nourish the baby orchid. At this point, roots would begin to develop as well, but not in Coralroots. Instead, a short branched rhizome with rounded bumps begins to grow.

Rhizome of Corallorhiza (right) looks like coral, or did to Abraham Gagnebin, who named the genus in 1755 (USDA Forest Service).

Once above ground, most orchids start making their own food via photosynthesis, in tiny green solar-powered food factories in their leaves (and sometimes stems). But Coralroots have no leaves, only bladeless sheaths, and they are rarely green.

Corallorhiza innata (= C. trifida); note short branched rhizome and sheaths on stems (W. Muller 1904).

How do Coralroots survive without roots or leaves? For many years, they were thought to be saprophytic, decomposing and living off organic matter in the soil. Some reputable botany websites still describe them as such. But in fact, they cannot decompose organic matter. Instead, they're part of a complex drama, featuring three very different players.

Most orchids end their fungal dependency after germinating, but a young Coralroot can't. Without photosynthesis it needs a source of food, and will rely on the fungus for the rest of its life. But wait ... fungi don't photosynthesize either! This is where things get complicated.

Tripartate relationship: tiny orchids, fungal network, tree. Note that NO arrows come from the Coralroots.

If we search underground, just beneath the soil surface, we see that the fungal mycelium is linked not only to baby Coralroots, but also to tree roots, in a mutually beneficial relationship. A tree makes carbon compounds via photosynthesis and shares them with the fungus. In return, strands of fungal tissue increase the tree's uptake of water and minerals. Most importantly, the fungus fixes nitrogen in a form the tree can use.

However, while the trees and fungi are helping each other, the Coralroots continue to suck up nutritious carbon compounds from the fungal mycelium. From whence come such compounds? Might they come from dead organic matter decomposed by the fungus? Apparently not. Studies have shown that carbon delivered to the Coralroot by the fungus is produced by photosynthesis, not decay. Trees are the ultimate source.

Knowing this, what are we to think of Coralroots, those delicate little beauties of the forest? They live off carbon produced by trees and delivered by fungi, and contribute nothing in return ... NOTHING! Some botanists call them "heterotrophs" (consumers) that eat fungi. But "parasite" is more widely used and perhaps more accurate, given that they suck nutrients from fungal tissue. And yet no harm to the host has been shown. It's probably best to call Coralroots "mycoheterotrophs"—an awkward but nonjudgemental term specific to their tripartite relationships (Leake 1994).

USDA Forest Service.

What do you think of Coralroots? Do you forgive them their selfish ways? It's tempting to do so, but be aware—they have another dark side, and it has to do with sex! Stay tuned.

Sources (in addition to links in post)

Britannica's mycoheterotrophy article is detailed, interesting and clear. Here's their summary, my insertions in brackets:

"Mycoheterotrophs leach the carbohydrates that the fungi obtained from symbiotic plant partners [trees] and provide no reciprocal benefits. This interaction creates a tripartite relationship involving the autotrophic plant [tree], the fungus, and the mycoheterotrophic plant [Coralroot], with the mycoheterotroph serving as the ultimate sink for the carbon fixed by the autotrophic plant."

Leake, JR. 1994. Tansley Review No. 69. The biology of myco-heterotrophic ('saprophytic') plants. New Phytologist 127:171-216. Free access.

Leake, JR. 2005. Plants parasitic on fungi: unearthing the fungi in myco-heterotrophs and debunking the ‘saprophytic’ plant myth. Free access. 

USDA Forest Service. Celebrating Wildflowers: Coralroot Orchids. This is a wonderful website, offering so much for us to enjoy and learn! I wish I knew whom to credit. Accessed July 2026.

The Monthly Orchid—an introduction

The pouch-like lips of Fairy Slippers (Calypso bulbosa) are exquisite with their purple patterns and bright yellow hairs. No wonder fairies collect them at night to wear for dancing! (NPS)

Once again, I'm starting a series of posts about South Dakota plants—in part so that I can learn more about the state's flora (I'm still contributing to the online guide). In 2024 I wrote about trees, mostly the less familiar ones from the eastern part of the state. Last year I focused on ferns and fern relatives (lycophytes), and became a pteridomaniac in the process!

This year, after writing descriptions for sedges and rushes, and while starting on grasses, I considered doing a series about graminoids. But after a few weeks of struggling with species differentiated by tiny green structures, I came to my senses and went in a totally different direction—orchids! Their flowers are colorful, sweet-scented, diverse, relatively large, and highly-evolved.

Twenty-seven native orchid species have been reported from South Dakota. Some have large colorful flowers. Others have sweet-scented flowers, or flowers with unusual parts (e.g. threadlike or deeply dissected petals). But most of our species have flowers that aren't showy. They're small and subdued in color—white, greenish, yellowish, or brownish red. But up close they're gorgeous and obviously orchids.

Spotted Coralroot (Corallorhiza maculata); the white lip with purple spots has yellow gobs of pollen hanging over it; lip c. 6 mm long (MWI).

Like almost all orchids (99%), ours have a combination of features unique to the family: a LIP petal (tepal), a COLUMN consisting of the stamen(s) and pistil, POLLINIA made of pollen grains, and minute SEEDS.

Parts of an orchid flower (Serena Aceto).

The LIP or labellum is one of an orchid flower's six tepals (three sepals and three petals). Five of the tepals are more or less alike, but the lip is quite different—in shape, color, size and more. It's also distinctive among species, and is used in identification (fortunately it's easy to see). The lip appears to provide a landing platform for visitors, and species-specific forms are thought to be designed for specific pollinators—the product of coevolution.

Stream Orchid (Epipactis gigantea) has lips with "tongues"; these move when the flower is bumped, hence its other name: "Chatterbox"; flowers to c. 5 cm wide (Dcrjsr).

The lip of Loesel's Twayblade (Liparis loeselii) is showy relative to the other tepals, 2 of which are horizontal and threadlike; flowers to c. 1 cm long (MWI).

Most orchids have a single stamen, which is joined with the pistil to form a COLUMN. Among species, columns differ in size, shape, color and function. In White Lady's-slipper (below), the top of the column presses against the lip, preventing pollinators from leaving the way they came in. Instead they must exit via a narrow slit in the back of the pouch. Inexperienced bees may take up to 15 minutes to find the exit, and may fall prey to crab spiders lurking within! (source)

Small White Lady's-slipper (Cypripedium candidum) has a glossy white inflated lip to 2.5 cm long; yellow flap with red spots is the column tip (MWI).

In most orchids pollen grains are amassed into POLLINIA, bound together by threads of clear sticky viscin. Pollinia are carried off by pollinators to be deposited (hopefully) on stigmas of the same species. The advantages of dispersing pollinia rather than pollen grains will be explained shortly (below).

Ophrys orchid with a pollinator about to get hit with yellow pollinia (ErwinMeier; arrow added).

Finally, orchids produce the tiniest of SEEDS, which number in the thousands or even millions per flower! This means that there are equally numerous ovules in a single pistil. Now we see the advantage of pollinia. Thousands or sometimes millions of pollen grains packed into a pollinium land on a stigma all at once, ready to fertilize the multitude of waiting ovules.

Orchid seeds are very different in another way. Most flowering plants (angiosperms) have double fertilization, producing seeds with both an embryo and a stash of endosperm to feed the seedling as it starts its life. But not orchids. There is no double fertilization, and the tiny seed contains no endosperm to sustain the baby seedling. Even the embryo is much reduced—just a small mass of mostly undifferentiated cells.

Seed of Autumn Coralroot (Corallorhiza odontorhiza), 0.2 mm long! © Freudenstein 2024, CC BY-NC.

When an orchid's capsules dry and split, millions of dustlike seeds are cast to the wind, seemingly with little chance of survival. And yet orchids are said to be one of the most widespread families of flowering plants, both geographically and ecologically! (Brittanica) Seeds and their strategies are what fascinate me most about orchids, far more than the showy diverse flowers. But this introductory post has gone on long enough. So we will stop here, and let the mystery be for now.

"Orchideae" from Ernst Haeckel's Kunstformen der Natur (1899); see source page for names.

Sources (in addition to links in post)

Arditti, J, et al. 2025. Darwin’s prescient letter regarding orchid mycorrhiza. Lankesteriana 25: 83–102. http://dx.doi.org/10.15517/y157kw10 

Brittanica. Orchid. Accessed May 9, 2026.

Freudenstein, JV. 2025. Orchid phylogenetics and evolution: history, current status and prospects. Annals of Botany 135: 805–821. https://academic.oup.com/aob/article/135/5/805/7901162

Wikipedia. Orchids. Accessed May 9, 2026.

By the Shores of Lake Lahontan

Camping on a different kind of beach.

Beachcombing through tufa, not sand.

Last fall, on my way home from California, I drove through northwest Nevada intending to make several brief geostops on the shores of Lake Lahontan. But it was so interesting and so curious that I stayed over two nights. By doing so, I was able to follow in the footsteps of one of the great pioneering geologists of the American West—Israel C. Russell.

I met Russell several years ago in the Mono Basin, not far west of Lake Lahontan. Guided by his spirit, I toured the basin seeing landscapes through his eyes and his words (Russell 1889). He was a terrific writer, and that was a time when geologists weren't constrained by today's conventions of scientific writing. It was wonderful to share his awe and appreciation for the novel geologic features he found.

Israel Russell (source). "his physique gave to the eye little suggestion of that capacity for sustained effort and endurance without which his more strenuous exploration would have been impossible." (Gilbert 1906)

In 1880, Russell joined Senior Geologist Grove Karl Gilbert of the US Geological Survey in a study of what were thought to be relic shorelines, across a huge area in western Utah. Impressed with Russell's diligence and field skills, Gilbert gave him his own project—a survey of similar features to the west in Nevada It would commence the following year.

During the first field season, Russell made a geological reconnaissance "during which about 3500 miles were traversed in the saddle" (all quotes his unless noted]. That winter he prepared a "Sketch" of his findings, starting with a description of the region—expansive, harsh, unusual in the extreme, and "standing in marked contrast in nearly all its scenic features with the remaining portions of the United States."

"The traveler in this region is no longer surrounded by the open, grassy parks and heavily-timbered mountains of the Pacific slope, or by the rounded and flowing outlines of the forest-crowned Appalachians, and the scenery suggests naught of the boundless plains east of the Rocky Mountains or of the rich savannas of te Gulf States. He must compare it rather to the parched and desert areas of Arabia and the shores of the Dead Sea and the Caspian."

Though unlikely to attract "the pleasure-seeker", the region offered a "peculiar fascination" to geologists, for two reasons. First, "the absence of vegetation gives such unusual facilities for investigation". Often not a single tree can be seen for hundreds of miles, and only the rare robust sagebrush offers any hope of shade. Rock and soil are well-exposed.

The barren range beyond the playa was one of Lahontan's many islands and peninsulas.

Second, "the character of the problems to be solved" was irresistible. This was an area rich in geologic novelties, Lake Lahontan being a fine example. Water is scarce to non-existent, and more than a few travelers have chased mirages, gagged on alkaline muck, and perished from thirst. Yet a host of scattered shorelines, tufa deposits, and gravel bars suggest Lahontan was once a huge freshwater lake sparkling in the sun.

Lake Lahontan in its prime, just 13,000 years ago (source).

Routes traveled [red lines] & areas surveyed (Russell 1885); source.

Russell and various assistants would spend two field seasons studying and measuring Lake Lahontan. They determined the elevations of basins (the old lake bed) and terraces on the slopes above (shorelines). They sketched ancient gravel bars and sand spits, and collected samples of the various types of tufa. And they surveyed and mapped nearly 8500 square miles. The result was monumental: Geological History of Lake Lahontan, a Quaternary Lake of northwestern Nevada; Monograph 11 of the US Geological Survey.

"Depth of Lake Lahontan at highest water stage" (excerpt, note depth measurements); source.

"A characteristic specimen of thinolite" [a controversial type of tufa]; source.

From "Map of Lake Lahontan" (c. 20 x 32 inches in its entirety). Note shaded relief overlying contour lines—subject of a future post.

During my visit last year, I toured a northern arm of Lake Lahontan—today's Black Rock Desert and "Lake" Winnemucca to the south.

Black Rock Desert playa is open to driving, fireworks, camping & more (I stayed on the shoreline above). 

From the Black Rock Desert, I drove south along today's Lake Winnemucca, and stopped at a large tufa tower next to the highway. Tufa is sometimes described as a porous limestone; it forms where freshwater meets carbon-dioxide-rich waters, such as springs, streams, and lakes. In his monograph, Russell described three types and partially clarified an "embarrassing" earlier hypothesis for thinolite.

Tufa tower along NV Hwy 447.

Tufa up close.

Lake Lahontan shorelines above today's mostly-dry Lake Winnemucca.

With that stop my visit to Lake Lahotan came to an end. It was much too brief, and I left determined to return.

"The bare mountains reveal their structure almost at a glance, and show distinctly the many varying tints of their naked rocks."

Sources

Gilbert, GK. 1906. Israel Cook Russell. J. of Geology 14:663-667.

Russell, IC. 1885. Geological History of Lake Lahontan, a Quaternary Lake of northwestern Nevada; Monograph 11 of the US Geological Survey.

Russell, IC. 1889. Quaternary history of Mono Valley, California (in USGS 8th annual report). Russell's report was reprinted in 1984 by Artemisia Press, Lee Vining, CA.