20 December 2011

Stylidium debile

Stylidium debile F.Muell., a triggerplant from Queensland and New South Wales in Australia, is in near constant bloom in my greenhouse. They bear small, attractive flowers on multiple inflorescences and are easily propagated by cuttings. Of all the Stylidium in cultivation, this is perhaps the most common because it seems to thrive on neglect and tolerates nearly any conditions. For more, see the International Triggerplant Society.

18 November 2011

Sarracenia flava var. cuprea

Sarracenia flava var. cuprea, the copper-colored variety of the yellow pitcher plant described by Donald Schnell in 1998. This taxon is the progenitor of several popular copper lid cultivars. The photo was taken at Hortus Botanicus in Leiden during the International Carnivorous Plant Society conference in 2010.

13 November 2011

October's Berry Go Round and crowd funding of science

Unexpectedly, I found that my post on protogeocarpy was included in October's Berry Go Round, a blog carnival on plant science, over at Slugyard. Mike B. of Slugyard put the carnival together in a pretty neat way, adapting Poe's "The Raven" for the Halloween edition of the Berry Go Round.

Hyobanche sanguinea, a parasitic plant native to South Africa and the subject of Andi Wolfe's #SciFund project.
Photo source: Winfried Bruenken, Wikimedia Commons.

Unrelated by also interesting, have you noticed all of the opportunities out there for crowd funding a project? Musicians and artists have been ahead of the curve on this trend; for example, I'm supporting the recording of The Guggenheim Grotto's next album over at PledgeMusic. And then there's a multi-year project of one artist seeking support on Kickstarter to complete a beautiful illuminated manuscript of Darwin's On the Origin of Species (h/t Matt Young at Panda'sThumb). So just a few months ago, a few scientists got together and wondered, "Hey! Where are our crowd funding opportunities. Will it work for science?"

You bet it will work! I would encourage you to check out Andi Wolfe's #SciFund project and support it if you can. Andi is a professor in the department of Evolution, Ecology, and Organismal Biology at The Ohio State University that I just began attending this autumn, and the funding from her #SciFund project will support undergraduate research. (Also check our her lab's blog.)

I think overall that the #SciFund challenge will benefit scientists and the public. Scientists must strive to explain often difficult topics to a "why should I care?" public, flexing their PR muscles, and the public gets the opportunity to feel like they're a part of the scientific process. It's exciting and I can't wait to see what comes from it. Good luck, Andi!

31 October 2011

Let me rewrite that headline for you...

Arthritic dog lays down for an hour, falls asleep, seems more calm

...or as the New Jersey Herald puts it, "Reiki expert channels energy to heal pets, humans."

No, really. I was shocked. This is journalism? I was also a little embarrassed; this is my hometown newspaper. I always thought it outperformed the newspaper of my adopted hometown, Mount Vernon, Ohio. In my opinion, this was an abominable piece of journalism.

When Cindy Nolte arrived at the home of her client for their afternoon Reiki session, Kodi was waiting for her. Walking with a slight limp because of his severe spinal arthritis, Kodi braved the discomfort to rush to greet her.
The pair walked inside and Kodi lay down on the living room floor as Nolte began to meditate and focus a positive energy flow to Kodi's aching bones and muscles.
Within moments, Kodi's labored breathing had slowed down, and he slowly began to relax into a sleep-like state. Nolte used no words, she didn't even touch Kodi during their hour-long session that seemed to leave Kodi re-energized and invigorated.

I can't believe my hometown newspaper reports this pseudoscience as if it were real, with no disclaimers or editorializing by the journalist that these practices are unproven and frequently mocked by the scientific community. And shame on that woman, Cindy Nolte of Fresh Look on Life, for taking advantage of gullible and desperate people by telling them she can make them (and their pets?) feel better just by thinking at them. Dear lord, just think of the harm she could do if she turned her healing thoughts to murderous ones! (Snake oil, anyone?)

Seriously, though, that this passes muster for journalism (or at best a fluff piece) does not bode well for the journalism profession or the New Jersey Herald. I am sad to say that I've lost respect for the paper.

Acting as a conduit for the flow of positive healing energy, Nolte uses her experience to help her clients quiet their minds and connect to the energy, which can be challenging for busy humans.
"Some people have never tried anything like this before, and trying to quiet their minds after 30 or 40 years is a challenge. Just think of contacting a friend after 30 years; there is a lot to talk about. It's the same for us. We really don't talk to ourselves, so there is a lot of chatter to get through," Nolte said. "We need to learn to go inward and accept ourselves at our own individual level."

Oh. So Cindy Nolte is some sort of life coach that teaches people how to relax. Why not just say that? Why couch the albeit mockable need for a life coach in reiki healing energy woo and weirdness? If you ignore the reiki, this sounds somewhat reasonable. Relaxation is good, and some people are bad at doing it. But she doesn't stop there:

Animals, on the other hand, seem to have a natural understanding of Reiki and the energy it uses to heal, Nolte said. This allows them to benefit from the treatment that the Reiki sessions provide.

Oh. They do? Dear journalist, where's the balance? Actually, screw balance, where is the outright mocking of this pseudoscience? Where's the scientist in the article exposing this practice for the ridiculous assertion that it is with not a shred of evidence to support it? Even a single throwaway line from a local scientist would have been an improvement, though overall the article would still be a loss for those who value logic and reason.

Yes, I realize this article was a slice-of-life in-the-community approach, but it wrongly lends the validity of the newspaper to the laughably irrational tenets of reiki practitioners, who are no more rational in their beliefs than proponents of homeopathy. Unfortunately, people with little knowledge of science could be easily convinced by this charlatan, Cindy Nolte, and her thought energy. I encourage all readers to visit Quackwatch's examination of reiki and this entertaining piece at scienceblogs for a pretty thorough debunking.

I look forward to the next article in the series from the New Jersey Herald on how someone is selling vials of homeopathic "treatments" consisting entirely of water and how it's helping relieve her client's pet opposum's tinnitus. I'm sure Betty the opposum writes excellent testimonials.

02 October 2011

Protogeocarpy in the bizarre Australian plant genus Alexgeorgea

Alexgeorgea - male vegetative plant with inflorescences (left), a female vegetative
plant (center), and the above ground portion of the female flower (right), positioned
for the comparison but would normally be shorter. Source: Sherwin Carlquist.
Botanists often love language, so much so that they attach a name to even rare phenomena - odd, tongue-twisting descriptive names that are so infrequently used that one sometimes wonders why they bother at all. Wading into the obscure language of botanists today I encountered this doozie: protogeocarpy. Breaking the term down into its constituent parts gives us proto (before), geo (ground), carpy (relating to the carpel - the ovule and seed producing reproductive organ). Perhaps two-thirds of this word looks familiar to you. The news of the newly described genuflecting geocarpic plant from Brazil, Spigelia genuflexa, has made headlines around the world as a photogenic botanical oddity. I even wrote about it briefly.

ResearchBlogging.orgMost dictionaries and encyclopedias will tell you that geocarpy is a process by which a plant stem or inflorescence elongates and deposits the developing fruits into the ground. And they will probably mention the famous example of the peanut being buried up to 10 cm below ground. But that's not entirely accurate. Geocarpy is a broad term that encompasses any subterranean ripening of the fruit. Technically, Spigelia genuflexa and peanuts are perfect examples of a type of geocarpy known as hysterocarpy, "in which the fertilized ovary penetrates into the soil by means of a long peduncle," according to the book Dispersal Biology of Desert Plants by Karen van Rheede van Oudtshoorn and Dr. Margaretha W. van Rooyen. In other words, these flowers were fertilized above ground, then the developing fruits were deposited into the soil later. In another twist, only some of the fruits of Spigelia genuflexa were deposited, which the authors of Dispersal Biology would further demarcate as an amphicarpic habit.

The subterranean fruit of Alexgeorgea,
about the size and shape of an acorn.
Source: Sherwin Carlquist.
So in keeping with our geocarpic plant theme, let me introduce the small Australian genus Alexgeorgea. In sharp contrast to the above examples, the three species in this Western Australian genus of restiads (members of the Restionaceae family, related to grasses and sedges) produce their female flowers below ground with all but the stigmas, the pollen-receptive part of the carpel, being subterranean. These are truly protogeocarpic plants because fertilization of the ovary and maturation of the fruit occur below ground.

The male plants (yes, the plants in this genus are dioecious, meaning there are separate male and female plants) of Alexgeorgea nitens appear like many other Australian restiads, so much so that it was first described by the German botanist Christian Gottfried Daniel Nees von Esenbeck in 1846 as Restio nitens. von Esenbeck had mistaken deformed portions of plants above ground, possibly the result of a smut fungus, as the fruit and included this information in his description when placing it in the large genus Restio. Overlooked for the next 130 years were the subterranean fruits of this species until Sherwin Carlquist, an American botanist and one of my botanical heroes, noticed the ephemeral thread-like stigmas of the female flowers emerging from the sand. He admitted that had he not been present during the short period in which the plants produce the female flowers, the peculiar subterranean flowers and fruits would have likely remained unknown to science. Carlquist first came upon these plants in 1974 and later described two species in a new genus named in honor of the Australian botanist Alex George in 1976. Consider how fortuitous this discovery was in not only being in the right place at the right time, but also being able to recognize that the minute above ground portion of the female flower no more 3 cm tall was worthy of further investigation.

Male flowers in the background;
emergent female flower parts seen
in front as red or purple threads.
Source: Sherwin Carlquist.
What you see above and to the right in the photo is a portion of the underground rhizome, which can be several meters long. The female flowers are borne directly on the rhizome 10 to 15 cm below ground in white sandy soils. Overall, Alexgeorgea species are not the most attractive species out there, but they have a certain charm in their unusual habits.

But why? What conditions lead to the evolution of geocarpy? What are the advantages? Carlquist hypothesized that in Alexgeorgea the evolution of a single-seeded subterranean fruit was an adaptation in response to a predominant fire ecology in Western Australia. Fruits at or below ground are protected from the extreme heat of fire. Indeed, many other plants in Western Australia have adapted to frequent fires by producing their fruits at ground level (basicarpy). More widely, geocarpy is assumed to have evolved in several plant lineages in response to the harsh environments in which the species grows. In Dispersal Biology of Desert Plants, it is noted that plants may develop a geocarpic habit to ensure close proximity of the offspring in favorable micro-habitats. For example, Alexgeorgea persists in seasonally wet peaty sand and if it instead relied on wind dispersal of its fruit, it is assumed that a larger percentage of offspring would fail to germinate in favorable soils by being blown far from the small region in which it can thrive. The disadvantages are obvious: restriction of seed dispersal, limitation of population genetic structure, and the possibility of small stochastic events wiping out entire colonies.

Regardless, this is a fascinating plant habit and an equally fascinating genus. Leave it to Australia to bring us yet another botanical oddity!


Carlquist, S. (1976). Alexgeorgea, a bizarre new genus of Restionaceae from Western Australia.
Australian Journal of Botany, 24 (2), 281-295 DOI: 10.1071/BT9760281

Briggs, B., Johnson, L., & Krauss, S. (1990). The species of Alexgeorgea, a Western Australian genus of the Restionaceae. Australian Systematic Botany, 3 (4), 751-758 DOI: 10.1071/SB9900751

15 September 2011

Spigelia genuflexa: You reap what you sow

Spigelia genuflexa leaning over to deposit its seed in the soft soil. Photo by Alex Popovkin (CC by 2.0)
If you haven't yet checked out the beautiful photos of this newly described species, definitely do so. Spigelia genuflexa Popovkin & Struwe is a member of the Loganiaceae, or strychnine family, just described yesterday in the journal PhytoKeys. It is unusual in the family by its geocarpic habit; I'll let Alex Popovkin and his co-authors explain:

During fruit maturation, the basal infructescences bend down towards the ground, depositing the fruit on the surface (and burying it in soft kinds of ground cover, e.g., moss), whereas the upper ones do so slightly but noticeably.

This plant clearly doesn't trust that gravity will do the job appropriately. A geocarpic habit is rare but common enough to have representatives in several families. The most interesting to me about this story is that the first author of the study and one of the authors of the taxon is an amateur botanist in Brazil whose efforts have paid off. And as an aside, the guest editor for Popovkin's paper was Sandra Knapp, the botanist I mentioned earlier who was instrumental in successfully altering the botanical nomenclature code to allow online publication of new taxa.

ScienceDaily published a decent press release on this new species and the University of British Columbia's Botany Photo of the Day provided an excellent summary. (I highly recommend adding the Botany Photo of the Day site to your RSS feed.)

07 August 2011

Fabulous news: Nepenthes thorelii has been rediscovered

Time to celebrate! Botanist François Mey has confirmed that Nepenthes thorelii, a tropical pitcher plant native to Vietnam, has been rediscovered. This species was first collected in the mid-1800s, then formally named in 1909, but has most recently only been known from the earlier herbarium specimens. All specimens in cultivation that were labeled N. thorelii were revealed to be related, but did not share key morphological characteristics with the type specimens of the species. And so, it was thought that N. thorelii could have been extinct both in the wild and in cultivation.

Then, in 2009, thoreliigate happened. Vietnamese growers uploaded photos to one of the carnivorous plant forums, showing them holding plants that François identified as true N. thorelii. At one point, the Vietnamese growers refused to cooperate further. When François and other experts searched for the plants at the type location and in the exact spot of the photos, no plants matching the description of N. thorelii were located. It's really quite sad as these plants were clearly poached and sold.

But now François, along with botanist Alastair Robinson, is back in Vietnam and has successfully rediscovered a population of N. thorelii. As Alastair notes, this is the first time in 102 years that qualified botanists have been able to see the plants in situ and collect proper herbarium specimens. Their initial reports and some beautiful photographs can be found here. According to the comments in the forum posts, there are about 100 plants of both genders at this site, located on military land, so chances are that it will remain protected.

Congratulations to all involved! Work like this is very valuable in conservation and taxonomy. Truly fabulous news.

26 July 2011

The great golden digger wasp returns!

The great golden digger wasps (Sphex ichneumoneus), which I wrote about in a post last year on free will and the Concorde fallacy, returned this year to the same spot in front of Higley Hall at Kenyon College in the soft, gravelly soils under an overhang. A swarm of dedicated females has been entertaining our equally dedicated summer science students and visitors. The nest site is conveniently right outside large floor-to-ceiling windows, perfect for viewing the activity of this wasp species. Their short lives will come to an end soon, but they have been able to dig, provision, and complete dozens of burrows. Brava, wasps. I hope this site remains popular for the species for years to come.

21 July 2011

Botanists vote to allow online publication of new taxa

The excitement (and nervous uncertainty) is tangible on botanical taxonomy e-mail lists with the recent news that the nomenclature section of the International Botanical Congress, the governing body of the rules on how we describe new species and other taxa, voted at this year's Melbourne conference to drop the requirement that all new taxa must be described in print publications. If the rule is adopted by the whole Congress, we'll soon see new taxa being published in online-only peer-reviewed journals like PLoS ONE.

Much of the discussion on online-publishing has surrounded the necessity for proper archiving and a sense of permanence on an otherwise ephemeral online realm where the paradox that full permanence may not be achievable yet it's hard to completely erase some online substance reigns. Last year Sandra Knapp of London's Natural History Museum took this outdated policy to task and defiantly published four new species of Solanum in PLoS ONE. She was able to skirt the printed publication requirement by following the other International Code of Botanical Nomenclature rules that allowed her to print out at least 10 copies and distribute them to libraries and a central name index. If the full IBC follows suit and votes for this new rule allowing online publication of new species, no one will have to follow Knapp's example.

This issue had come up at the last Congress in Vienna six years ago, but online journals were just getting off the ground and archiving systems were either poorly managed or lacking entirely. Heck, I was still using Livejournal. A lot has changed in the past six years. The measure didn't pass in Vienna, which I think was the right decision. We waited long enough that the technology caught up to meet the rigorous demands of proper taxon description.
Levenhookia murfetii from Mount Lesueur, Western Australia
Lowrie A, and Conran JG. 2011. Triggerplant Journal 1 (2): 4-29.

ResearchBlogging.orgIn a related matter, I recently noticed that noted Australian botanist Allen Lowrie, famous for his carnivorous plant descriptions, has described a new species of stylewort (Levenhookia) in the online-only Triggerplant Journal (Volume 1, Number 2), founded by Douglas Darnowski and Greg Bourke. It's beautifully illustrated with lovely photos, but as far as I can tell, and even though the journal has an ISSN, the description by Lowrie and his colleague John G. Conran of the new species Levenhookia murfetii (named in honor of Denzel E. Murfet) is not "effective" yet. And so until the new rules from the IBC go into force, all publications of new taxa should still be in print, or at the very least Lowrie and Conran need to print out ten copies of their article from the journal and submit it to libraries and one index, just as Sandra Knapp did with her Solanum species. It may be early to judge based on this, but so far the name Levenhookia murfetii has not been entered into the International Plant Names Index.

Update (27 July 2011): I recently heard from Greg Bourke, one of the publishers of the Triggerplant Journal, that the description of the new species Levenhookia murfetii was indeed printed out and distributed to validate the description. This is good news for this particular description. Perhaps IPNI is just behind on updating the database.

Now the zoologists can sit back and be jealous of the botanists, since the ICBN's zoological counterpart, the International Code of Zoological Nomenclature, has been considering such an amendment to their rules since 2008 but it has not yet taken any action. I'm okay with this.

Lowrie, A., & Conran, J.G. (2011). An overview of the Australian Levenhookia (Stylidiaceae) complex, including a new species (L. murfetii) and observations on the triggering methods employed for pollination and outcrossing. Triggerplant Journal, 1 (2), 4-29

21 May 2011

ASM 2011 Conference: New Orleans

I have arrived in lovely New Orleans! For the next couple of days, I'll be spending my time at the general meeting of the American Society for Microbiology in lovely New Orleans. I'm here at what will likely be my last ASM conference with the Slonczewski Lab from Kenyon College, where we are presenting our recent work on multi-drug efflux pumps, pH homeostasis, and fluorescence microscopy. It's really a great education for the undergraduates that my PI, Dr. Joan Slonczewski, brings along to the meeting.

The opening session was this evening and, I think, much better than the previous two years. Each of the three lectures was intriguing, accessible, and well-prepared. I was reassured that I will be heading off to graduate school in the right direction - evolution and ecology - by the fact that I found the lecture by Dr. Nicole Dubilier on symbiotic relationships between sulfur-oxidizing bacteria and marine invertebrates most enjoyable. Similarly, last year in San Diego at ASM 2010, I thought the best opening lecture was that by Dr. Nancy Moran, who spoke about her work on the relationship between endosymbiotic bacteria and leafhoppers that I wrote about last year.

The second lecture by Dr. Liping Zhao was equally fascinating. He discussed what eating well does for us physically via our microbial gut flora. This work has been in the news somewhat, but I found the thorough lecture perfect for tying together all the disparate pieces of the story. His work shows that for morbidly obese people, a change in diet from a high fat, low fiber diet to a more sensible one allows the microbiome in the gut to shift from an abundance of pathogenic organisms that can cause longterm disease to beneficial and benign organisms. For some reason, the attendees at the reception after the lectures seemed much more restrained around the over-abundance of food in the exhibit hall...

The last lecture, which I found the most difficult to follow from the detail and fast pace, was on environmental stressors that can trigger heritable changes in the organisms studied, mostly yeast. We're not talking Lamarckian giraffe's neck scale of environmentally acquired traits, but the analogy was striking.

That's all for now, but I may check in at least once more during the meeting if I'm not too exhausted in the evenings. Tomorrow we dine at the Court of Two Sisters, which sounds exciting.

11 May 2011

Backyard biology: New greenhouse

Since I've made the decision to accept my admission offer to Ohio State University's Evolution, Ecology and Organismal Biology PhD program beginning in autumn 2011, assuring my presence in central Ohio for several more years, Adam and I decided to take advantage of a great deal on a greenhouse:
Yes, it's a rickety aluminum-frame polycarbonate panel 6' × 8' that probably won't retain very much heat in an Ohio winter, but at least I have something I've always wanted! Adam and I spent last weekend digging out the site, leveling the foundation lumber, and hauling stone to fill in the base. Once the landscaping grows in, we should have a fantastic little hide-away nook behind the greenhouse, perfect for an Adirondack chair or two.

The greenhouse will not be heated much in the winter, making it the perfect spot to overwinter hibernating Sarracenia, like those I just received from the North American Sarracenia Conservancy (NASC).

 These Sarracenia alata seedlings are propagated by members of the Grower Committee at NASC from legally-collected parent plants to maintain the genetic variety of these rare and threatened carnivorous plants. The plants I received today were from Texas, Louisiana, and Mississippi. If I do everything right, they'll grow, flower, and possibly be reintroduced in suitable locations. Many of the plants NASC acquires are from boggy habitats that are bulldozed in the name of progress or road widening. This is an excellent example of ex-situ conservation and is meant to be a complementary component to land acquisition and conservation easements (in-situ conservation).

I suppose I'm still thrilled with the idea of having my own greenhouse just steps away, but I imagine I will become less enthusiastic about it this winter when I need to trudge out there through feet of snow.

09 May 2011

Is the common teasel carnivorous?

Dipsacus fullonum, the common teasel. An "urn" type
water storage, where dead arthropods collect.
Source: Björn Appel at Wikimedia Commons.
ResearchBlogging.orgDipsacus fullonum, the common teasel or Fuller's teasel, is an asterid native to Europe, Asia, and northern Africa, but is also introduced (and sometimes naturalized) in many other parts of the world, including North America. You would probably recognize it as a common weed with the distinctive comb-like inflorescence. 19th century naturalists recorded finding dead arthropods in the water-collecting cups formed by the fusion of leaves around the stem. Early suspicions for this structure focused on a protective function, since ants are unlikely to cross the water barrier to prey on the flowers.

However, the idea that the plant could be deriving some benefit from the dead insects evolved at least as early as 1877 when Francis Darwin, who, possibly influenced by his father's book, Insectivorous Plants published in 1875, submitted a paper on the topic to be published in the Proceedings of the Royal Society of London. Since then, there have been additional field observations and laboratory experimentation, especially those of Miller Christy in the 1920s, but, as F. E. Lloyd noted in his 1942 tome The Carnivorous Plants, there still was no experimental proof of carnivory. So does the common teasel derive any benefit from the prey it captures in the water urn?

The short answer is yes. Now we have experimental evidence that suggests the plants derive benefit from feeding dead dipteran larvae. Peter J. A. Shaw and Kyle Shackleton of Whitelands College, Roehampton University in London described their results in a recent article published in PLoS ONE. They found that while supplemental feedings of larvae to the plant did not increase overall above-ground biomass, both the seed biomass and seed mass-to-biomass ratio were significantly larger in plants that were fed. The authors note that the results need to be replicated, but this initial finding suggests Dipsacus fullonum meets one of the criteria to be considered a carnivorous (or paracarnivorous) plant.

Bravo to the researchers. It will certainly be interesting to see how the carnivorous plant research and enthusiast community reacts to this news. It's still uncertain how the plant derives the benefit from prey, but it's becoming more clear that Dipsacus fullonum is a candidate for status as a carnivorous plant. What exactly is a carnivorous plant, though? The exact criteria for establishing evolved carnivory and not just a happy paracarnivorous accident has been debated for years and will be the subject of a later post.

Shaw PJ, & Shackleton K (2011). Carnivory in the Teasel Dipsacus fullonum - The Effect of Experimental Feeding on Growth and Seed Set. PloS one, 6 (3) PMID: 21445274

15 April 2011


Nepenthes! I've had a proliferation of Nepenthes putting out pitchers, so I went around taking photos today. From the top left across the rows: Nepenthes boschiana × densiflora, N. jamban, N. maxima × trusmadiensis, N. alata, N. ventricosa (? from Lowe's), Nepenthes "Miranda", N. mikei, unknown Nepenthes hybrid that looks like Nepenthes x henryana to me, and N. mikei again.

I've been growing Nepenthes for about 5 years, but until now I have not had any flower for me. And of course, it had to be the one that I rescued from the Lowe's deathcube!

Nepenthes ventricosa with inflorescence from a Lowe's deathcube

27 February 2011

Utricularia sucks: Aquatic carnivorous plants that evolved vacuum traps

"Hi." Trap of Utricularia inflata, clearly showing
the door, trigger hairs, and concave walls.
Scale bar = 500 μm
Source: Vincent et al., 2011.
Utricularia, commonly known as the bladderworts, is a genus of approximately 230 species of carnivorous plants that have evolved an amazing suction trap to supplement their nutrient requirements by trapping and digesting convenient little arthropoid or crustacean packets of nitrogen, phosphorous, and other essential chemicals. Not all species are aquatic, as this cosmopolitan genus has also evolved species with lithophytic (growing in or on rocks), epiphytic, and terrestrial habits.

The rootless aquatic species are most notable for their tiny underwater bladder-shaped traps dotting the web-like system of stolons like aquatic chandeliers. Each trap is only a few millimeters long or less and possess a trap door surrounded by sensitive hairs that trigger the trap door mechanism to open, quickly sweeping the water - and any tasty prey contained therein - adjacent to the trap into the bladder. Keep in mind that each trap is only two cell layers thick when considering the pressure differentials and forces involved in prey capture.

Gazing upon this wondrously evolved botanical curiosity, naturalists in the 19th century thought that it was a passive system as comically illustrated in F. E. Lloyd's 1942 book on carnivorous plants (see below). Charles Darwin and others thought prey was simply enticed into entering the trap, much like a mouse entering a passive mousetrap. Since that time, and thanks to Lloyd's research in the early 20th century, we now know that the bladder traps of Utricularia are much more complex, involving the active setting of a trap and a rapid response once triggered, as illustrated in Lloyd's figure (below), which can only be described as the potential inspiration for the elaborate and beguiling board game Mouse Trap. Rube Goldberg would be proud!

Source: F.E. Lloyd. 1942. The Carnivorous Plants. Waltham, Mass.: Chronica Botanica Co.
The description is too long to reproduce here, but the following amused me: "...which allows the lever l to swing
downwards when the door is actuated again by, it is confidently hoped, a second mouse. In the meantime, the mouse
first caught can employ his time admiring the interior effect, and possibly suggest improvements." (pg. 267)
So by the mid-20th century, we had a pretty good idea of how these traps worked. Water is pumped out of the trap, producing the familiar "set" concave wall appearance. An unlucky crustacean, perhaps a Daphnia, swims too close to the trigger hairs, which relays that signal to the trap door, which swings open so quickly, no one had been able to quantify it before now. And here's where the exciting new research comes in. Physicists decided to record prey capture using high-speed cameras and measure the morphology of the door as it opens. The best thing about this, I believe, is that they put all of their supplemental material on YouTube.

The above video from the new article shows a copepod from the genus Cyclops being trapped by a Utricularia inflata bladder. The whole process occurs in less than one millisecond and is thus one of the fastest plant movements known. The poor little copepod seems utterly stunned. And no wonder! Olivier Vincent at the Laboratoire Interdisciplinaire de Physique, University of Grenoble and colleagues estimated that fluid velocities entering the trap can reach 1.5 meters per second (approximately 3.4 miles per hour) with maximum fluid accelerations of 600g. (Most humans lose consciousness at 4-6g.) Furthermore, in the video above you'll notice the copepod swirls down and around in the trap. The authors propose an interesting idea, that the trap morphology propels prey forward, then down into a swirling motion, preventing the immediate escape before the trap door closes again.

More impressive is the work they did investigating the door morphology as it opens. I can only imagine how precise this microscope, camera, and laser setup had to be in order to capture the exact moment when the door buckles and lets water flow in:

The also produced a dynamic simulation of the door opening:

So there we have it. Amazing new research adds to our understanding of one of the most unique carnivorous plant capture mechanisms. We've come a long way from Darwin's day and I certainly hope there's more to uncover. I'll leave us with just one more video, produced directly by the authors and posted on YouTube:


Vincent O, Weißkopf C, Poppinga S, Masselter T, Speck T, Joyeux M, Quilliet C, & Marmottant P (2011). Ultra-fast underwater suction traps. Proceedings. Biological sciences / The Royal Society PMID: 21325323

23 February 2011

IPPP #3: Pinguicula primuliflora

The third installment of the Infrequent Plant Profile Project, a project I began a while ago at my old livejournal account. I know that I will not stick to a schedule if I designed one, so I choose to make this project informal and infrequent. These will be profiles of plants that interest me and of the circumstances of their original description.

Pinguicula primulaflora "Rose" - the multiple-flowered variety
Source: Alexander (fischermans) at the International Carnivorous
Plant Society forums.
ResearchBlogging.orgToday's species is Pinguicula primuliflora C.E.Wood & R.K.Godfrey, the primrose butterwort, is a carnivorous plant from the Southeast United States. As a member of the carnivorous plant genus Pinguicula (family Lentibulariaceae), this species shares the characteristic fleshy, sticky leaves that capture and digest arthropod prey that are unable to escape. This provides the plants with nutrients that are lacking or unavailable from the peaty or sandy soils they inhabit.

A photo of one of my first plants, which
I quickly killed due to my inexperience
growing this genus. I've had much more
success now.
Pinguicula primuliflora was first described by American botanists Carroll Emory Wood and Robert Kenneth Godfrey in a 1957 paper published in Rhodora, the journal of New England Botanical Club. Their work at the time was focused on researching the flora of the southeastern United States. In the course of their work, they made many collections, including other well-known species from the region, including P. caerulea, P. lutea, P. pumila, and P. planifolia. Their specimens revealed a fifth species that had not previously been described. Pinguicula primuliflora is found from southwestern Georgia and western Florida to southern Mississippi. It is distinguished from the other southeastern species by its showy Primula-like flower and its unusual ecology for a Pinguicula, being found in the shade of evergreen shrubs and wherever there is flowing water.

It is surprising that a species could have been overlooked by so many botanists working in the southeastern US until 1957 when P. primuliflora was formally described. This just goes to show how important extensive research into the flora of a region is. It also provides us with an example of how rigorous research, a large sample size, and careful measurements of morphological characteristics of closely-related species can reveal unique populations worthy of recognition at the rank of species or subspecies.

Today, P. primulaflora is one of the most widely-cultivated Pinguicula species and can be found frequently in hardware stores, often in the appropriately-named "Death Cubes." It is a prolific species, producing many rooted clones where leaves touch the soil substrate. Many cultivars of this species exist, including a spectacular double-flowered variety (pictured above)

C.E. Wood Jr., & R.K. Godfrey (1957). Pinguicula (Lentibulariaceae) in the southeastern United States. Rhodora, 59, 217-230

15 January 2011

A Genlisean Effort: A Tale of Two Trans-Atlantic Dispersal Events in the Carnivorous Plant Genus Genlisea

An illustration from 1858 on the closed and open Atlantic Ocean.
ResearchBlogging.orgSouth America and Africa look like they fit together snuggly, like puzzle pieces. It's so intuitive that children can grasp this notion without the aid of a formal education in geology. As an accepted theory, plate tectonics draws on evidence from several supporting disciplines, including paleontology and biogeography. Paleontology and geology are, of course, the primary fields where evidence for continental drift arises, the theory being largely proven by work from the recently deceased Dr. Jack Oliver.

Evidence also comes in the form of the remarkably similar flora and fauna and the evolutionary patterns found within certain taxa. However, we must be careful with examinations of extant plant species. Despite the great distance, a remarkable number of plant genera have made the journey and now have established representative species on both sides of the Atlantic. Susanne Renner, of the University of Missouri and Missouri Botanical Garden at the time, published a review in 2004 of the 110 flowering plant genera in 53 families that have dispersed across the Atlantic. She based her work on a 1973 publication by the botanist Robert Thorne (of the Thorne system of classification) and expounded on the likely dispersal routes. Thorne, who lacked key data from gene sequences, identified 111 genera with trans-Atlantic dispersals. With the advantage of 31 years and molecular clock data, Renner revised this number by subtracting genera proven to not be monophyletic and adding previously unrecognized genera. Most of these dispersals appear to be recent in terms of geological time and water currents can carry dispersal in both directions across the Atlantic, while wind currents are typically only responsible for transport from South America to Africa. Renner also thoroughly discounts the common speculation that plant trans-Atlantic plant dispersal could have been aided by birds, noting that it's unlikely given the circumstances of bird migration, dispersal, and digestion (frugivorous birds empty their guts frequently, so it is unlikely any seed eaten would survive the journey).

Genlisea violacea.
Photo source: Noah Elhardt
Renner, writing in 2004, does note that one genus, Genlisea, has a disjunct distribution due to "entry from the boreotropics" instead of long-distance dispersal. In other words, the evidence at the time pointed to a larger northern hemisphere distribution of the genus that crossed the North Atlantic either on then-connected land masses or over short spans of water. She therefore excludes it from her analysis.

Genlisea is an interesting genus of about 22 species found in tropical South and Central America and Africa, including Madagascar. The center of diversity in South America appears to be in Brazil, where up to seven species may be found in one area. The species, commonly called corkscrew plants, are carnivorous, specializing in protozoans and small crustaceans. They're also rootless. The semi-aquatic or terrestrial plants are anchored by their corkscrew-shaped traps that are actually modified subterranean leaves or highly modified stolons. There are some lovely publications out there with nice SEM images of the traps, but most are being paywalls, so you can feast your eyes upon these. Further, the entire Lentibulariaceae family, of which three carnivorous genera (Genlisea, Pinguicula, and Utricularia) seems to be undergoing really rapid evolution to the point that some species, such as Genlisea margaretae, are shedding their genomes. Genlisea margaretae in particular currently holds the title for smallest known angiosperm (flowering plant) genome, with some chromosomes as small as bacterial chromosomes. Researchers believe that this rapid evolution could be the result of significant mutations they found in the key respiratory enzyme cytochrome c oxidase, which could be producing more reactive oxygen species, causing great damage to the plant's DNA, including whole helix-breaks and nucleotide substitutions.
Current distribution of Genlisea; colors indicate number of species in a given area. Figure from:
Fleischmann et al. 2010. Molecular Phylogenetics and Evolution, 56: 768-783.
But beyond their fascinating morphology, carnivorous habits, and genetics, Gelisea are an interesting genus for their trans-Atlantic dispersal, now supported by data published in 2010. The data, consisting of three chloroplast DNA sequences from as many species as they could get their hands on, collected by Andreas Fleischmann and his colleagues indicate that the genus originated in the Neotropics, likely in present-day Brazil. There are two main divisions in the genus, one of which is wholly confined to South America (subgenus Tayloria). The other subgenus (Genlisea) originated in Africa, but one small clade of this subgenus are only found in the Neotropics. The authors first weigh the arguments for an ancient emergence of Lentibulariaceae when South America and Africa were still connected as Gondwana, but this idea is rejected since the family Lentibulariaceae is known to be relatively younger than the Gondwanan breakup. Instead, they propose the remarkable idea that the genus was established in Brazil, dispersed to Africa (likely by fast-moving currents in the Atlantic on "floating mats"), diverged and evolved in Africa, then made a second dispersal back to South America, where a group of species, which have a greater morphological and genetic affinity to those found in Africa, are located. Their case for this theory is well-supported. Just think about how amazing this is, though. Two dispersal events: a colonization of Brazil by subgenus Tayloria, then long-distance dispersal to Africa (founding subgenus Genlisea), a speciation event in Africa, a dispersal back to Brazil and subsequent re-colonization by members of subgenus Genlisea. I don't know about you, but I'm exhausted just thinking about the magnitude of this herculean genlisean effort.

Renner, S. (2004). Plant Dispersal across the Tropical Atlantic by Wind and Sea Currents International Journal of Plant Sciences, 165 (S4) DOI: 10.1086/383334

Fleischmann, A., Schäferhoff, B., Heubl, G., Rivadavia, F., Barthlott, W., & Müller, K. (2010). Phylogenetics and character evolution in the carnivorous plant genus Genlisea A. St.-Hil. (Lentibulariaceae) Molecular Phylogenetics and Evolution, 56 (2), 768-783 DOI: 10.1016/j.ympev.2010.03.009