JIM CONRAD'S
NATURALIST NEWSLETTER
Issued from Hacienda Chichen Resort
adjoining Chichén Itzá Ruins in
Yucatán, MÉXICO

May 8, 2016

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DUST-BATHING FLYCATCHER
Earlier this week we had our hottest temperatures of the year, mid-afternoon temperatures of over 100° F (38°C) at the Hacienda 106 and more in Mérida (42°C). One afternoon during the hottest part of the day a Social Flycatcher whirred to a dusty spot on the ground, beat his wings against the dust while stomping and scratching with his feet, and fluttered about until plenty of dust must have penetrated beneath his wings and settled over his body. Then he just sat on the ground, his wings spread from his body and his beak open, as shown at http://www.backyardnature.net/n/16/160508fc.jpg

I assume that the dust and heat caused some body parasites to abandon ship during this slow cooking process, and I assume that it wasn't comfortable to the flycatcher. Birds don't sweat, so to cool off they can open their beaks so that evaporation from their moist mouths, throats and lungs cools them a little.

Above I mention the the bird "whirred" to the dusty spot. I'm referring to how Social Flycatchers make brief whirring sounds, apparently with their feathers -- somewhat like a turkey's low-frequency, long-carrying feather-drumming. Social Flycatchers make this sound when they rush at other birds or otherwise want to bring attention to themselves. When one wants to drive another bird from the birdbath, he may fly at the bird whirring. However, no other bird was near the hot, dusty spot on the ground when this bird landed there whirring. My impression was that he'd been perching in the Guácimo tree for some time considering whether he should put up with the heat, dust, and my sitting in front of the hut, and then when he decided to take the plunge he did so with self-encouraging, whirring bravado.

After about half a minute the bird shook himself violently, creating a little dust cloud, flew off and began preening.

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CLIMBING FERN
On April 14th as I hiked small gravel backroads around Lacanja Chansayab in Chiapas's Lacandon Reserve, along the road I came upon a vine with extraordinary compound leaves twining across a dense wall of tree and shrub branches, shown at http://www.backyardnature.net/n/16/160508ly.jpg

In Mississippi we've something like this. You can confirm how similar the "leaves" are at http://www.backyardnature.net/n/x/climfern.htm

The Mississippi plant was the invasive Japanese Climbing Fern, Lygodium japonicum, a real fern, with extraordinary anatomy. Our Chiapas fern is the closely related LYGODIUM VENUSTUM, native from central Mexico and the Caribbean south through Central America and most of tropical South America. Species of Lygodium often are known as climbing ferns.

What's amazing about climbing fern anatomy is that what appears to be the fern's wiry stem stretched across my fingers in the picture is actually the frond's midrib, or rachis. The two "fronds" in the picture and several others along the wiry stem, are subdivisions of one extremely long frond. In the technical words of my old Bailey's Manual of Cultivated Plants, in the genus Lygodium "... the 'lvs.' are secondary pinnae, which are palmately or pinnately compound or decompound."

On the margins of the leaflets, or secondary pinnae, notice the tiny, dark green, fingerlike items, of which a close-up of several is seen at http://www.backyardnature.net/n/16/160508lz.jpg

Ferns reproduce with spores, and these structures, sometimes called marginal spikes, are where the spores are produced. You might know that fern spores are produced inside microscopic, baglike-items known as sporangia, and in many kinds of ferns the fronds' groups of sporangia are partly or completely covered with a thin layer of tissue called the indusium. This climbing fern's marginal spikes are composed of overlapping indusia. In the picture, each green, scale-like item is an indusium that if you should peel one back you'd find sporangia inside which spores are developing.

In Mexico Lygodium venustum sometimes is known as Hierba de la Víbora, which can be loosely translated as Snake Plant. It's famed as treatment for snakebite and scorpion stings. After being bitten, the fronds can be eaten directly. Also, teas can be made of the whole plant for diarrhea, dysentery, and for various female diseases.

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ELEPHANTLEAF BRAKE FERN
On April 14th when I was hiking small gravel backroads around Lacanja Chansayab in Chiapas's Lacandon Reserve, not far from where the climbing fern had turned up, and similarly entangled among a dense wall of tree and shrub branches, there were more typical-looking ferns, though big ones, with fronds about six feet long (2m). You can see them reaching for the road's light at http://www.backyardnature.net/n/16/160508pt.jpg

Because of their large size, at first I thought these might be the Giant Leather Ferns often seen in the mangroves and marshes along the coast, but those ferns produce their spores in clusters (sori) scattered all across their fertile fronds' lower faces, while you can see the very different situation on these Chiapas ferns at http://www.backyardnature.net/n/16/160508pu.jpg

In this species, the spore-producing sporangia are clustered beneath the frond segment's curved-under margins, which serve as the indusium. In fern parlance, such turned-under margins are said to be "revolute."

Up north the best-known ferns with sporangia gathered beneath revolute margins are the Bracken -- maybe the most abundant fern on Earth -- and the various cliffbrake species. Those ferns belong to the Brake Fern Family, the Pteridaceae, so when we look for members of the Pteridaceae found in lowland Chiapas it's easy enough to figure out that our big fern is PTERIS GRANDIFOLIA, often known as the Elephantleaf Brake.

Elephantleaf Brake has its English name by virtue of the species' occurrence in Florida and the Caribbean as well as central Mexico south through Central America, and in South America south to Peru. Other Pteris species occur in Chiapas but they're not as large, plus the fronds' venation underneath is distinctive. A close look at both the veins and the sporangia is at http://www.backyardnature.net/n/16/160508pv.jpg

Sporangia are like little bags full of spores. Across each sporangium's top there's a crest-like ridge of cells. When the sporangia are mature and the weather is dry, the crest-cells start drying up and shrinking. This causes tension to develop across the sporangium's thin surface. At a certain point the tension becomes so great that the sporagnium bag breaks open with a snap, and spores are thrown out, to be carried away on the wind. In the picture you can see empty sporangium covers and the slender, narrow, orangish, connected-together ridge cells that snapped them open.

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STAR-SCALED FERN
In mid April when I was in the Lacandon community of Lacanja Chansayab in Chiapas's Lacandon Reserve, the lady operating the small campground where I set up my tent maintained a small area where epiphytic orchids and ferns adorned the branches of small trees. Apparently she regularly sprayed the area with a hose because the tree limbs there were much more mossy than branches on trees in the surrounding forest, and nearly all the various orchid species were in bloom, though in the nearby forest I hadn't seen any orchids blossoming.

In this artificially maintained spot, there was an unusual-looking fern with very long, slender fronds bearing large, oblong sporangium clusters -- or sori -- that were arranged in single file along both sides of the fronds' dark midribs. You can see the rich-brown, elongate sori on wilted, curling fronds snaking atop a tree's dense covering of mosses at http://www.backyardnature.net/n/16/160508pl.jpg

A closer look at a frond's undersurface, not only better showing the brown sori but also numerous tiny scales scattered across the fronds' surfaces, at http://www.backyardnature.net/n/16/160508pm.jpg

These sori appear to have never had indusia, indusia being the very thin, often silvery membranes that may or may not partially cover fern indusia. The most commonly encountered ferns with such sori belong to the Polypody Fern Family, the Polypodiaceae, of which the North's Common Polypody and Resurrection Ferns are members. However, that's a big family whose members usually display very different frond shapes. Fortunately, an online identification key is available for keying out "Neotropical Fern Genera" here.

Our frond's distinctive features quickly keyed out to the genus Pleopeltis, in the Polypody Fern Family. More browsing on the Internet informed me that the taxonomy of that genus is a mess, and I saw that most Pleopeltis species don't look like ours. However, one species, a widely distributed one and commonly occurring in the humid American tropics, did more or less look like ours, and that was PLEOPELTIS ASTROLEPIS. Our ferns' sori are a bit longer and narrower than others shown on the Internet, but I can't find any other species it could be.

Pleopeltis astrolepis sometimes is called the Star-scaled Fern. Its English name may reflect the fact that in 1977 it was discovered in Broward County, Florida. The species is well described in the online Flora of North America," which tells us that in Broward County "the plants are in danger of extirpation from development."

Elsewhere the species is distributed from southern Mexico and the Caribbean south through Central America to Peru and Brazil in South America.

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ROSARY SNOUTBEAN
On April 14th along small gravel backroads around Lacanja Chansayab in Chiapas's Lacandon Reserve, I thought I'd come upon a low-hanging species of vine I'd been wanting to photograph for a long time, but its flowers and fruits always have been too high for a good picture. You can see the vine at http://www.backyardnature.net/n/16/160508rh.jpg

Trifoliate leaves on a twining vine immediately suggest the big Bean Family, the Fabaceae, plus the fruiting capsules even at this distance look like they're legume-type fruits opening to reveal red beans. A closer look at the legumes and their striking beans is at http://www.backyardnature.net/n/16/160508ri.jpg

A much closer look at a single legume where we can see that each red bean bears a large black spot is at http://www.backyardnature.net/n/16/160508rj.jpg

Now that I saw the beans better I began thinking that this wasn't the poisonous Abrus precatorius I thought it was. Up in the Yucatan that vine's tiny, red-and-black beans often ornament trails through the woods, but the beans are more spherical, looking like little red eyeballs with black pupils. These beans are more flattened and look like red Lima beans with one end dipped in black. This was something new.

The stubby little legume with only two red beans, its constriction between the two compartments, and the long, sharp "snout" at the pod's tip made the vine easy to identify as RHYNCHOSIA PRECATORIA, in English sometimes known as the Rosary Snoutbean. It owes its English ID to the fact that it's found from Texas and Arizona south through Mexico and Central America to northern South America. In Spanish it's often known as Ojo de Perico, or Parakeet Eye.

Rosary Snoutbean vine specializes in disturbed habitats like our roadside, as well as cornfields and fences enclosing pastures, but also it turns up in open woods, on dry hillsides and a variety of other environments. I read that sometimes the beans are eaten, but they're so small it's hard to imagine anyone harvesting them for that purpose. Another use is more believable -- that they look pretty on bracelets and necklaces.

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CYDISTA TRUMPET FLOWER
On April 14th as I hiked small gravel backroads around Lacanja Chansayab in Chiapas's Lacandon Reserve, a prettily flowering vine dangled from trees at the roadside, shown at http://www.backyardnature.net/n/16/160508cd.jpg

The flowers' deep corolla tubes, and the compound leaves' two leaflets on long stems, or petiolules, can be seen from below a flower cluster at http://www.backyardnature.net/n/16/160508ce.jpg

Such large, tubular flowers with five spreading lobes in few-flowered clusters on climbing, woody stems with two compound leaves arising opposite one another at stem nodes, immediately suggests tthe big Trumpet Creeper Family, the Bignoniaceae. Most flowers in that family bear four stamens -- sometimes only two -- as opposed to the more typical number five, and a peep into a blossom's throat finds four stamens, as shown at http://www.backyardnature.net/n/16/160508cf.jpg

The Trumpet Creeper Family is a big one in the humid American tropics, so other features were sought to help with identification. An outstanding field mark for this species is that its stems are sharply squared, and at the vine's stem nodes arise unusually large, leafy, rounded stipules, as shown at http://www.backyardnature.net/n/16/160508cc.jpg

Sometimes tendrils on vines of the Trumpet Creeper Family fork, and sometimes they don't. this species' tendrils don't seem to fork, as seen at http://www.backyardnature.net/n/16/160508cb.jpg

This turned out to be CYDISTA POTOSINA, with no good English name, though it's fairly common in southern Mexico, including the Yucatan Peninsula, where I've simply overlooked it until now, as well as much of the rest of lowland tropical America. The species' flowers can be either white or yellow.

The online Blioteca Digital de la Medicina Tradicional Mexicana reports that in southeastern Mexico the leaves of Cydista potosina are used generally for wounds, and along the Yucatan Peninsula's Caribbean coast an extract is used for insect and spider bites, plus there are other uses as well.

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CHIGGERY GRAPES
On April 14th as I hiked small gravel backroads around Lacanja Chansayab in Chiapas's Lacandon Reserve, a semi-woody, shrubby vine with small, white flowers dangled from trees along the road, shown at http://www.backyardnature.net/n/16/160508tf.jpg

A close-up of the flowers is at http://www.backyardnature.net/n/16/160508tg.jpg

Along with the facts that the flowers are small, their white corollas have slightly curved tubes, the corolla lobes spiral as they unfold from the flower bud, and that the lobes show pleats down their middles, other important field marks are that the vegetative parts are covered with a mat of short, white hairs and -- maybe most diagnostic of all -- the flowers are arranged on just one side of their raceme rachises, and the rachises themselves curl at their ends. Moreover, the youngest flowers arise at the rachises' tips, with older flowers and maturing ovaries residing lower down. Such flowering structures can be called "scorpioid racemes," the word "scorpioid" meaning "scorpion-shaped," referring to the curl in a scorpion's tail.

Only a few plant families have flowers arranged in scorpioid racemes, and this was the main feature leading me to the plant's name, which is TOURNEFORTIA HIRSUTISSIMA, a good old Linneaus name. Tournefortia species belong to the Borage or Forget-Me-Not Family, the Boraginaceae. At least the US Department of Agriculture supplies the plant with the colorful English name of Chiggery Grapes. Tournefortia hirsutissima has an English name because the plant is distributed from Texas and Florida south through the Caribbean, Mexico and farther southward.

Over its large area, Chiggery Grapes is used in traditional medicine by several cultures, in various ways. One use is for treating diabetes. In fact, a paper by A. Andrade-Cetto and others appearing in a 2007 edition of the UN's FAO publication AGRIS reported that extracts from Tournefortia hirsutissima "... significantly lowered the plasma glucose levels in diabetic rats... "

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THE AZTECS
This week I finished reading Gary Jennings' monumental 1980 historical novel "Aztec," kindly left in the Hacienda's visitor library by a German guest. The Aztec civilization dominated upland central Mexico from the 1200s until the society was destroyed by Spanish invasion in 1521. Wikipedia's extensive page on the Aztecs is at https://en.wikipedia.org/wiki/Aztec

The Aztecs didn't make good neighbors. Their foreign policy was to conquer neighboring communities and make them pay "tribute" in the form of food, luxury items, firewood, gold, slaves, and the like. Sometimes the Aztecs attacked neighbors in order to capture warriors to be sacrificed by having their beating hearts cut out during religious ceremonies. In 1487, for the reconsecration of the Great Pyramid of Tenochtitlan, the Aztecs chronicled that hearts were cut from 80,400 living prisoners over the course of four days.

It's interesting to think that though the Aztecs were unusually obsessed with human sacrifice as part of their religion, Aztec society was structured more or less like all great societies -- elites, working masses, slaves, police/military, and religions, in the context of aggressive foreign policies. One wonders whether there might be a natural law that this is how all great societies must be ordered.

If such a natural law does exist, there's a loophole enabling some of us to opt out from feeling that we're part of that society. The loophole is made possible by the Sixth Miracle of Nature, as outlined on our Six Miracles Page at http://www.backyardnature.net/j/6/

The first five Miracles established a world in which things and events evolve in a programmed manner. Throughout human history, our genetic programming has predisposed us to commit a great deal of violence, including genocide. Also, most of us seem programmed to yield to authority, even when our leaders involve us in unwise policies. The Sixth Miracle -- which here on Earth only right now is flickering into existence -- grants humans with our big brains the potential for shifting our lives from being directed by genetic predispositions, to taking control of ourselves by countermanding our gene's demands. We can live by the standards of our minds, which can evolve faster than humanity's biological base.

For example, since all great societies feed on money and power, our big brains can be used to craft lives in which neither money nor power are very important to us, and thus we can become uninteresting to those in power, and sometimes they'll leave us alone.

Since one way big governments control is by manipulating what's wanted by its citizens, we can use our big brains to simplify our lives so we don't need much from them in the first place, and therefore give them less power over us.

Another feature of the Sixth Miracle is that once a person escapes the bondage of his or her own programming, and thus no longer is part of any great society in the usual way, new insights spontaneously crystallize as part of one's evolving awareness. New insights and new knowledge enable us more vividly to behold the world around us. We see beauty and spiritual meaning where we'd overlooked it before. This causes us to fall in love with the Creation, so that sustainable living patterns and empathy with other living things spontaneously enrich our lives and make our lives more meaningful.

And, if enough of us undergo this miraculous transformation, things might turn out pretty well, despite our biological histories and programming.

*****

Best wishes to all Newsletter readers,

Jim

All previous Newsletters are archived at http://www.backyardnature.net/n/.