Category Archives: Hard Science

Glen Rose Interlude – 2

Want to know what you missed? Go back and catch up.


The main reason most people have for visiting Glen Rose, Texas is for dinosaur tracks. Whether it’s to visit Dinosaur Valley State Park or the oxymoronic Creation Evidence Museum up the road, it’s all about dinosaur tracks. Before one Roland T. Bird came into downtown Glen Rose for a glass of lemonade and found a dinosaur track incorporated into a WPA-built bandshell next to the courthouse, the town was one of a multitude of towns southwest of Fort Worth boasting scenic views and excellent diners, but nothing that would convince people to travel from the other side of the planet to visit. Now, Glen Rose has a plethora of antique stores and art galleries to give a reason to stay, just so long as you don’t spend so much time stomping around in the Paluxy River that you lose track of daylight.

Since the original plan to go slopping around in the Paluxy was capsized by the closest thing to white water that I’ve ever seen on it, this meant lots of daylight for other endeavors. The dinosaur trackways are on what used to be muddy beachfront, so they tended to catch lots of other items during regular rounds of sediment deposition. While I have yet to come across any reports of actual dinosaur bone preserved in Glen Rose, that mud preserved a lot more. In particular, the area is simply rotten with exquisitely petrified driftwood, most of which looks as if it came out of the surf last week instead of 120 million years ago.


Those familiar with the fossilized logs at Petrified Forest National Park in Arizona might be a bit disappointed with Glen Rose petrified wood, or most of the stuff in Texas for that matter. The Glen Rose deposits rarely preserve whole logs: the vast majority of pieces resemble the chunks and bobs that wash up in the Gulf of Mexico today: the bark is gone, but the surf wasn’t strong enough to move big logs and stumps onto land, so most of what’s here are smaller pieces that were broken up elsewhere. However, it’s beautifully silicified, preserving knotholes and insect damage, and it’s considerably more forgiving of erosion than its mudstone matrix, so it once collected in large piles. A tough but workable stone, with obvious attractiveness and durability: when given that sort of resource for construction, of course the people Glen Rose put it to use.


Based on the buildings still extant incorporating local petrified wood, you’d think that the area would remain loaded with logs. Making a trip out to Glen Rose 15 years ago, I heard some of the backstory from the former mayor, who ran a now-defunct bookstore in the town square. According to her, most of the available logs and larger chunks that weren’t already incorporated into local buildings were picked up and sold for the rock shop trade in the 1950s, and the high quality of the wood meant that people were keeping a close eye on the buildings. She related how a gas station near the square, made almost completely out of local petrified wood, had shut down and the land purchased by a local church for possible expansion. According to her, the church was evenly split between those who wanted to restore the gas station as a piece of local history and those who wanted to sell the petrified wood to a wholesaler, and this was settled when the gas station “accidentally” came down in the middle of the night. The petrified wood was salvaged and sold, and half of the congregation hasn’t talked to the other half since.


Even acknowledging that (a) the story might be apocryphal and (b) I should have taken notes rather than depending upon memories from a decade-and-a-half ago, the gas station story is believable upon seeing the structures still standing. So long as Cretaceous rock remains in the Glen Rose area, additional petrified wood will eventually erode out and gradually migrate to the bottom of the valley, but all of the easy pickings have been gone since the Great Depression. With luck, though, enough will remain that some aspiring palaeobotanist should be able to identify and classify the local flora, and give as much of a view of the plant life of Creataceous Glen Rose as the trackways give of the fauna.

To be continued…

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Hanging around with the Fangirls of Dallas

We’re in the last couple of weeks before everything hits the fan. The flytraps and Sarracenia both come out of dormancy by the middle of March; that is, unless we get another one of those oddball end-of-February snowstorms like the one that surprised us last year. We’ve already had a hailstorm at the end of January, so anything’s possible. (At times like these, I’m happier than ever for the new space: between the hailstorm and the subsequent heavy winds, the one-two hit literally degloved the greenhouse. This would have been a problem if I still had anything frost-intolerant in it: instead, it’s full of flytraps, seedling pitcher plants, and triggerplants just waiting for one last cold snap to encourage them to bloom this season.) This time next month, free time will be something I hear about from ne’er-do-well cohorts, but for now, it’s time for an interview with the Fangirls of Dallas, my favorite Dallas fan group. Please excuse the hair. And the voice. I’m not going to age well, am I?

More fun with UV lasers: The Aloe Edition

Aloe bloom

Let me state up front that I hate Nerine Dorman, the acclaimed South African horror writer. This isn’t a minor hate. I have plans for a vicious and vile repayment for everything she’s done to me and for me, and she’ll have earned every last bit. This was the woman who, along with her husband, introduced me to the fynbos, the smallest and most fecund floral kingdom on the planet. They’ve forgotten more about fynbos flora, particularly aloes and euphorbias, than I’ll ever learn, but that’s not why I plan to gain revenge.

Aloe nobilis

It all started this spring, when my aloes started blooming. At this time, I only have two species on hand, A. vera and A. nobilis, and last winter’s repeated Icepocalypses did wonders for all of my South African and Australian flora. Instead of burning off or freezing off permanently, the cold snaps not only encouraged sprouting and growth in Roridula seeds I’d given up on, but it caused a bloom explosion in the aloes.

Aloe blooms
(As an aside, I’m regularly asked at shows by cactus and succulent beginners about their plants’ blooming or lack thereof. While many require at least some cooling period to encourage blooming, the biggest factor is ambient light. With most barrel cacti, regular interference from streetlights, porch lights, security lamps, and other artificial illumination throws off their circadian rhythms, even if it’s only for a few days during their normal blooming periods. I’ve also noted this in such common succulents as jade plants (Crassula spp.), and it’s absolutely vital for aloes. Protect your aloes from light pollution in the spring, and watch them go nuts.)

Aloe blooms
Now, things got even more interesting when taking a closer look at the blooms themselves. They closely resemble the blooms of indigenous North American plants that depend upon either hummingbirds or hawkmoths for pollination, and the confirmation that they had a similar attraction came when a ruby-throat hummingbird proceeded to give me grief when mowing the grass by the aloe planters. There’s a very good reason why Huitzilopochtli, the Aztec god of war, was often portrayed as a hummingbird, as these little monsters have no fear of man, beast, or god, and this one took severe umbrage at my interrupting his feed. Most people would look at the wonder of being attacked by a dinosaur in this day and age and move on, but I needed to know what set off the sort of response more likely to be encountered when haranguing a hummingbird’s nest.

Well, that night, I dusted off the UV laser flashlight used to view fluorescence in carnivores, and tried it on the A. nobilis blooms. The petals fluoresce slightly under UV, but the tips? Those glow a brilliant cadmium yellow, like a black light poster. Considering similar enthusiastic responses from hummingbirds from bladderwort blooms with comparable yellow fluorescence, this suggests either that blooms of this sort offer trace elements in their nectar needed by hummingbirds, or some other factor makes hummingbirds associate this sort of UV glow, and remember that hummingbirds can see well into the UV spectrum, with particularly good food. Time for more research, or at least time to pass on the observations to botanists and ornithologists who can examine things further.

Aloe bloom spike junction

With that observation, I then asked Nerine, without any other familiarity with aloe pollinators, about which birds might be attracted to the blooms. That’s when she informed me of sunbirds (Nectariniidae), which are enthusiastic aloe pollinators. Two groups of birds separated by the Atlantic Ocean, attracted by the same floral cues for the same reasons, and a group of plants able to be pollinated by a bird group from the other side of the planet for precisely that reason…so do the birds call the shots, or the flowers?

Aloe blooms
This is why I hate Nerine as much as I do, and why I’m not going to rest until I come out to her house and talk her to death. At the same time as all of this, I lucked into a copy of the absolutely incredible book Fynbos: South Africa’s Unique Floral Kingdom by Richard Cowling, Dave Richardson, and Colin Paterson-Jones, and now I know where my next trip outside of the US is going to be. As if I don’t have enough realms to research: now I’m addicted to studying fynbos flora, and I CAN’T STOP.

Introducing Myocastor coypus

Nutria

I love terrorizing my UK friend Dave Hutchinson with tales of the horrible, vicious wildlife in Dallas, because it’s like poking a Knox Block with a stick. He refers to Texas as “Australia Lite”, because he knows that unlike Australia, not every life form in my native land would try to kill him. No, most just want to knock him out, drag him back to their lairs, and lay their eggs in his chest. Worse, I have a passport now, so I just might come out to London, drag him onto a plane to Dallas, and sing to him the whole way back.

Anyway, so that Dave doesn’t soil his bedsheets every night, I wanted to show him something here that wouldn’t try to kill him, enslave him, or steal his wimminfolk. That can be a tough order, especially coming from a guy nearly taken out by his bicycle being hit by an armadillo in my back alley. (Not only can those little armored pigs run, but they JUMP, too.) It took an exotic intruder in one of the oddest places in the area, but I finally succeeded.

As mentioned a while back, I took a new Day Job out in the Las Colinas area of Irving, close to DFW Airport. For those unfamiliar with the concept, Las Colinas started out in the early Eighties as a tech hub, culminating with it becoming quite the symbol of dotcom excess about 15 years ago. All of that turned back into pumpkins and mice, but some of the oddities remain. First and foremost is the network of canals that run all through the eastern side of the area: apparently originally intended to make slightly hilly Dallas prairie a bit more tolerable, the canals had the side effect of attracting all sorts of wildlife. Egrets, herons, softshelled turtles the size of a garbage can lid, the occasional water snake, and the very occasional alligator all show up in the canals, but one of the biggest surprises here was a little guy I met on the daily commute from the train station to my office.

A few people here may know the story of the nutria, a South American water rodent that pretty much fills the niche there that the muskrat fills in the US and Canada. Nutria were first brought to the US as a possible source of cost-effective furs when beaver became endangered through the States: the market never took off, but nutria breeding numbers did, and they rapidly became a major pest in Louisiana. Part of this was due to their voracious feeding habits, and part was because nutria prefer to dig deep burrows into steep riverbanks. When said “riverbank” is a flood levee…well, you can imagine why they’re not exactly loved through the area.

Even fewer know that nutria are a rather common invasive animal in the Dallas area, but that’s because they’re incredibly shy and secretive. While I’ve seen the occasional burrow along creekbeds through the area, the only time I’d seen one before was when two ran out in front of me in the middle of a raging thunderstorm. They’re usually so secretive that one doesn’t even hear them slip into the water and swim off, which was why spotting “Gustavus” here in the morning light was an even bigger shock. His favorite lounging and feeding spot is a canal bank in the middle of a large park in the middle of Las Colinas, and he’s completely unafraid of the innumerable joggers and bicyclists who race right by his grazing area.

Nutria

That is, until one of those cyclists stops and tries to get his picture. Well, it’s not like he’s going anywhere soon: the three-foot alligator I spotted in another canal is a ways off, and Gustavus is big enough to be a major challenge for a gator that small. Which brings up the eternal question: in such a blatantly artificial and manufactured venue as Las Colinas, are introduced species residing therein really quite the menace they would be in more pristine areas? Or is this just giving them running room to spread out further? Either way, I suspect Gustavus is going to be here for a while.

Investigating UV fluorescence in carnivorous plants at grad student prices

Back in February, many of you may remember the distinctive paper in Plant Biology titled “Fluorescent prey traps in carnivorous plants” and the subsequent popular science reportage. As can be expected, this opened up a whole new series of questions as how carnivores attract insect prey, with the biggest limitation being the ability to study the phenomenon. The situation is aggravated by the wild variability of consumer-grade ultraviolet light sources, particularly ones that produce the correct frequency of UV to fluoresce carnivore structures. While many UV LED arrangements, such as the flashlights used for viewing UV ink stamps at nightclubs, will fluoresce these structures, they also tend to emit enough visible light to wash out the effect.

In trying to study this further, the problem lay with finding a UV source that produced the correct wavelength, cut back on the amount of visible light being emitted, and kept the cost of the final arrangement to a reasonable amount. The last immediately removed shortwave UV lamps, used for decades for viewing fluorescent minerals, from consideration, as these can run well outside of a typical underclass or grad student’s budget. Thankfully, it’s possible, with a little modification, to make a perfectly suitable and very effective arrangement that, while not necessarily precise, allows researchers to experience carnivorous plant fluorescence in the field.

AS&S violet laser

The core of this apparatus is a violet laser, which emits enough UV for any number of fluorescence effects. (As can be expected, violet lasers are now the go-to item at raves and music festivals for precisely this reason.) While available from many sources, this one came from American Science & Surplus. One limitation, due to US regulations, is that it uses a momentary switch to turn on and off, requiring the user to keep it held down in order to use it. Other than that, it has exceptional range, which means that it has enough power for more long-range field observation, such as seeking fluorescing carnivores at night.

DISCLAIMER: Since a violet laser produces a significant amount of UV, neither the Texas Triffid Ranch nor anyone involved with it takes any responsibility or accepts any liability for damages or injuries caused or abetted by the misuse of said laser. Keep this thing out of your eyes and the eyes of innocent bystanders, and wear protective eyewear when using it. Likewise, keep it away from exposed skin whenever possible.

Laser beam (unmodified)

The other limitation to using a violet laser is tied to the basic concept of a laser. Namely, it emits a beam of coherent light in a pinpoint. As the photo above shows, this means that the light from the laser scatters in air (the reason, by the way, why the visible lasers in science fiction movies and television are impossible, unless someone fires one into a cloud of gas or vapor), but not quite enough for our purposes. What’s needed is a coherent light that also spreads out laterally, just enough to cover a larger area and to view fluorescence effects without the visible light component washing it out. For that, we’re going to need an optical diffuser.

ThorLabs diffuser

Another thing to consider when working with UV is that standard glass absorbs UV: this is the phenomenon that allows people in glass greenhouses to work in full sun all day without suffering crippling sunburn. (Take this from an authority on “shedding like a monitor lizard all summer long”.) Because of that, standard glass diffusers intended for coherent and incoherent light won’t work. You’ll have to pay a bit more, but Thorlabs offers a series of fused silica diffusers designed for UV, in polishes from 120 grit to 1500 grit. Since I knew precious little of what I was doing, I bought one 120 and one 1500 to compare the effects, and then tested it with the laser back from the diffuser by about a centimeter.

Laser beam with diffusor

As the photo shows, the diffuser does an exemplary job of spreading the laser beam while still keeping it reasonably coherent. The only problem right now is with keeping the diffuser perpendicular to the laser and turning on the laser with one hand. In a very quick and dirty installation, this could be fixed with judicious application of the Time Lord’s secret weapon, but the more realistic plan involves constructing a clip for the laser that allows the diffuser to be adjusted for best effect. That’s in the future.

Sarracenia under visible light

Now the acid test. Since most of my previous experiments involved Sarracenia and Nepenthes pitcher plants, the first series of experiments involve going out into the middle of a collection of Sarracenia with the newly modified laser and viewing the effects. As important as using UV on the plants was recording their appearance under visible light, if only to see if the plant had any correlation between its markings under visible light and any fluorescence in UV. Hence, a quick photo of the pitcher is necessary before moving on.

Sarracenia under UV, first attempt

The first test of the newly modified laser was an unqualified success, at least to the naked eye. The beam stimulated fluorescence in most carnivores, including hints in sundews (particularly Drosera filliformis), as well as reddish chlorophyll fluorescence in Venus flytraps. In fact, the extreme fluorescence in Sarracenia of all species helps explain why Sarracenia seem to capture so many moths, and the next big project is to capture similar fluorescence, if any, in the genus’s relatives Darlingtonia and Heliamphora. The only limitation lay with the camera: working without a net, the fluorescence was barely visible in final photos, even if it was nearly blinding in person.

Sarracenia pitcher under UV

Contrary to popular opinion, this is not the cover to the latest Hawkwind album. While the fluorescence can be seen in the throat of the pitcher (on the right) and the edges of the lid (left), it’s still not perfect. Time for more experimentation with shutter speed and light sensitivity.

Sarracenia under UV with blue spots

One of the more interesting phenomena that was observed while working with the laser with Sarracenia were distinctive neon blue spots on either side of the lid interior, visible here on the upper left of the lid. Not all pitchers have these, but larger pitchers do, and they almost resemble fragments of Australian fire opal or blue ammolite to the naked eye. I have no idea if these work as additional lures to insect prey, but that’s yet another experiment for the near future.

Triggerplant blooms under UV

And as an additional treat for botanists, the laser apparatus also helps bring out UV colors and patterns in flowers as well. The hot pink blooms of the triggerplant Stylidium debile already stand out to human eyes, but under UV, they’re a brilliant neon pink. Combine that with known fluorescence in the blooms of other carnivores and protocarnivores (particularly Utricularia bisquamata, which has a spot that glows a brilliant DayGlo yellow under UV), and this laser arrangement could be used to study the attractiveness of flowers to insects without requiring special camera lenses or other equipment. If further tests with sticky trap carnivores such as Drosera and Byblis work out, it may also offer a way to search for possible attractants in protocarnivorous and potentially protocarnivorous plants as Probiscidea.

In summary, with the advent of inexpensive violet lasers, carnivorous plant researchers may now view fluorescent attractors in carnivores for the cost of dinner and a movie. I hope that this encourages further experimentation with UV on carnivores, particularly among college and high school students, as well as among layperson carnivore enthusiasts. As always, please feel free to ask questions or add commentary below, particularly concerning ways to improve upon the results.

Carnivorous plant fluorescence under UV vs. point-and-shoot

sarracenia_uv_1

While this may not look like much, the photo above is a scientific demonstration. Namely, what happens when you combine a large Sarracenia pitcher plant pitcher, a violet laser that throws off a lot of UV when properly scattered, and a camera whose owner needs further training for low-light operation. Alternately, it could be a demonstration of viewing the fluorescence of carnivorous plants under UV with less than $20 in equipment, because the glow is much more intense in person than in this terrible photo. Either way, new, better photos WILL follow.

On other developments, this marks the 700th post on this blog since it started two years ago tomorrow. Do I get a cookie for longevity?

In defense of ultraviolet

By now, a fair number of carnivorous plant enthusiasts know about the new paper on fluorescence of Nepenthes, Sarracenia, and Dionea traps under ultraviolet light. First and foremost, for all of you undergrad and postgrad students out there, take this as a warning not to procrastinate in finishing and submitting a scientific paper. I was about maybe a month away from submitting my own paper to the Carnivorous Plant Newsletter on the subject, and not only did the authors of this paper beat me to the punch, but they produced an exceptional paper that presented distinctive blue fluorescence spots that nobody else had caught before now. They did exceptional work, they deserve every last bit of publicity they’re receiving, and I just regret not having the proper gear for proper research.

That said, there’s a lot more to be done with fluorescence in carnivorous plants. I can state with authority that many other genera of carnivore fluoresce under UV, including at least two species of Heliamphora,Darlingtonia, and the two carnivorous bromeliads Catopsis and Brocchinia. In fact, Catopsis fluoresces brightly enough to hurt. There are other advantages to running around your carnivorous plant nursery with UV lights, but I’m getting ahead of myself.

The whole strange experiment with carnivores and UV started about five years back. Peter D’Amato of California Carnivores noted about three years ago how brightly some species of Sarracenia, particularly S. leucophylla, seemed to stand out under moonlight, and I noticed that myself when looking over Sarracenia propagation pools during a full moon. Likewise, after damage from sudden hailstorms, I took a good look at the trap contents of those particularly bright Sarracenia and noticed that a majority of the prey items consisted of moths. The moths didn’t have any particular interest in visible light color variations, and many would have no interest whatsoever in the nectar secreted along the rims and lids of the traps. So what attracted them?

Since I was the sort of kid who cracked most Encyclopedia Brown mysteries by the third-to-last page and who went digging to verify the plausibility or lack thereof of Danny Dunn novels, it wasn’t hard to recognize that the moths were seeing something that I couldn’t without assistance. The initial research was easy, but I’m again getting ahead of myself. The problem involved getting photos that verified observations. Almost anyone who studied any level of high-school botany or natural history remembers photos of flowers taken “with a UV filter” that allows UV-blind humans to see the patterns on seemingly boring flowers that draw in bees and sawflies. Just try to get a breakdown on how to do this, though, especially in the digital camera age. Half of the advice I received was completely worthless (hacking your camera to detect infrared does nothing, and just wasted my time), or it was tantalizingly vague as to how those photographers managed to pull it off. I even hired my adopted daughter Jenny to take photos of Nepenthes and Sarracenia while using a UV filter, but the results were inconclusive at best. That’s one of the reasons why I’m so impressed with the photos taken by the Plant Biology authors: they bypassed all of that by using low-light photography and controlling the exact wavelength of UV used.

In further developments, I’m still publishing, but only after quite a bit of revision. Among other things, it’s time to note the number of other carnivores that show similar fluorescence, and the variations therein. For instance, Darlingtonia, the cobra plant, fluoresces along its trap aperture, but it also has veins of fluorescence along the ala, or wing, that runs up the shaft of the trap, presumably to encourage insects up the ala to the aperture. Venus flytraps fluoresce, with varying patterns with different cultivars. Oh, and the greatest fluorescence among sundews is at the tips of its trapping hairs, with the dew at the tips absolutely shining under UV.

Now, there’s no reason why you can’t experiment with this as well. In fact, after running a few tests, I hope to present a regular shortwave and longwave UV display at plant shows comparable to fluorescent mineral displays in rock shows. This sort of equipment isn’t absolutely necessary, though, and most experiments in carnivore fluorescence can be done with a simple UV light.

Black light fluorescent fixture

To begin, don’t bother with standard “black light” fixtures, either fluorescent or incandescent. Not only do these put out relatively little UV, but they emit so much visible light that the plant fluorescence is nearly unnoticeable. These will still work with one exception, to be related later, but for most investigation, save the money for a better option. About the only fluorescence you’ll get off a carnivore with one of these comes from dying leaves, and if you can’t spot that under visible light, this won’t help.

UV LED flashlight

That better option is a good UV LED light, preferably a battery-powered one that can be used in the field. These days, with the drop in prices in UV-emitting LEDs, it’s possible to find plenty of good LED flashlights at affordable costs, with and without standard white LEDs for double duty. I picked up mine from American Science & Surplus for two reasons: it has six UV LEDs surrounded by white LEDs so I can use it as a standard flashlight, and the switch glows in the dark. You may laugh, but drop one of these in the dark, and that improves the odds of finding it.

Sonic screwdriver - closed

And then there’s the one I use for plant shows with lots of kids, because they completely lose it when I pull it out and turn it on. This, of course, is my scorpion detector, as it’s just as good at causing scorpions to fluoresce as carnivores. It has one good, powerful UV LED in the tip, which already makes it very handy for shows, and it has a pen attachment at the other end for leaving notes on business cards and stickers. The best thing about it, though?

Sonic screwdriver - open

It extends. Particularly when showing the bright patches at the back of the throat of a Nepenthes pitcher, that’s a lot less intrusive than manhandling a pitcher into place for a larger light source. It won’t work well in bright light, but it gets the job done.

Now, instructions for using LED lights. If at all possible, try to use your new lights in as dark a set of conditions as you can get. When working outside, try for a new moon and a minimum of street and porch lights for the best effect. Indoors, go for the darkest room you can get and let your eyes adjust to the darkness before lighting everything. Contrary to news reports on how these “glow in the dark”, the effect is going to be a bit subtle, much like using UV lights on a piece of opal. With proper precautions, though, the effect is not only obvious, but one of the LED flashlights mentioned above can detect carnivores from as much as three meters away. Go for a longwave UV lamp, such as those used for diamond prospecting, and have some real fun.

And for a last word, there’s one additional benefit in wandering through your carnivorous plant collection with a UV flashlight. My dear friend Ryan Kitko recently wrote about the bladderwort, Utricularia bisquamata, that was infesting his shield sundew. U. biquamata has quite the reputation as an aggressive pest in carnivore collections, but I have a soft spot for it. Firstly, it’s very easy to care for, and it makes an excellent starter plant for those who want to work with bladderworts but who don’t have the facilities to raise any of the true aquatic species. Give U. bisquamata soggy soil and lots of light in a standard terrarium, and it takes over, producing lots of white-pink slipper-like blooms with a pastel yellow spot on the top.

The other reason why I’m so fond of U. bisquamata? Get outside with a UV flashlight and find out for yourself. That yellow spot may be pastel under visible light, but under UV, it fluoresces like a black light poster. Considering how many birds are able to see into varying frequencies of UV, I now understand why both the migratory ruby-throat hummingbirds and their competing rufous hummingbirds won’t stay out of my greenhouse. I’ve had hummingbirds literally tapping on my office window to get at U. bisquamata and U. sandersonii blooms, and now I know exactly why.