July 30, 2017
Whenever and wherever livestock grazes, you're going to have horseflies. At the rancho with its cattle and burros, you can find them throughout the year, and it seems to me that lately they've been particularly mean. When I jog at dawn they settle on my back and legs; even when I'm biking a few attach themselves and start cutting away. My horsefly miseries are nothing compared to the livestock's, however, as a shot of a small patch of burro hide testifies at http://www.backyardnature.net/n/17/170730hf.jpg
As that picture was being taken, one landed on my leg, and a close-up of that one is at http://www.backyardnature.net/n/17/170730hg.jpg
I was able to swat at the ones plaguing me so they seldom drew blood. The poor burros' defenses were limited, however. With their tails they could flail at those toward their rear ends, and they could throw their heads back and against those on a small portion of their shoulders, but otherwise large parts of their bodies simply couldn't be reached. Stomping their feet and kicking helped a little, but their main defense for places out of reach with the tail and head was to shiver or shimmy their skin, which they could do with surprising well. They must have special muscles attached to their skin enabling them to quiver without moving their body parts. Shimmying caused many horseflies to move on, but if one really wanted to feed, rippling skin didn't stop them, and they'd settle and drink all they wanted, and leave blood oozing from their cuts.
Back in Texas where Ia microscope was handy, I got a good picture of a horsefly's head, emphasizing the mouthparts. It's at http://www.backyardnature.net/n/13/130721tc.jpg
In that picture, the downward-directed, paddle-shaped item is the labium, with which the fly sops up liquid, including blood. The labium is like a sheath wrapping around slender, sharp knife blades with which the fly can slash through skin to get at blood. In the head picture, the sharply pointed, brown item between the labium and the antennae pointed to the picture's right border is one of two maxillary palps, which help the fly feel and maybe smell/taste whatever they touch.
Of course I wanted to identify the flies in the above pictures, which seem to be of two different species. However, the world of horseflies is a big one spread through several genera. For orientation on horseflies in the Yucatan I was lucky to find a PDF document on the Internet dealing with horseflies of the Yucatan, in Spanish (in which language they're called tábanos, and downloadable for free.
That undated document, authored by Pablo Manrique Saide and others, says that worldwide the Horsefly Family embraces about 4290 species, with 207 of those species turning up in Mexico, and 25 in the Yucatan Peninsula. The document also says that along the Yucatan's coast the yellowish Diachlorus ferrugatus is the dominant species, so probably that's the one that pestered us so unrelentingly during our 2011 summer on the Caribbean north of Mahahual. After that, the dominant species are members of the genus Tabanus, especially Tabanus commitus.
AIR PLANT BUDDING
Late last year as the dry season was getting underway, in November or so, in the dusty, crinkly forest along the trail from the rancho to the main road, I noticed a scraggly, thick-leafed plant shriveling up in the dryness and losing some of its leaves. I knew this plant, and knew that its leaves, with scallop-margined blades about the size of a hamburger, did something special. A leaf was collected, tucked into my pocket, and when I returned to the rancho the leaf was placed on some moist soil in a pot. In only three or four days, at the indentations between several of the blade margins' crenations, tiny, white rootlets formed, mantled with almost microscopic root hairs. These formed on the leaf's underside. You can see a picture of the rootlets on the flipped-upside down leaf at http://www.backyardnature.net/n/17/170730bs.jpg
The leaf was carefully returned to its moist soil, the rootlets directed toward the soil, and in about a week little green sprouts appeared on the upper side of the leaf, from the same indentations. About three weeks later, the leaf appeared as shown at http://www.backyardnature.net/n/17/170730br.jpg
Once these sprouts along the leaf's margin were about finger high and crowding one another -- the leaf itself now withered and decaying -- some of the sprouts were transplanted to a spot near the hut so I could have the fun of watching it grow, and have souvenirs of the hot, wickedly dry day I stuffed the mama-leaf into my pocket. Nowadays the plants are about knee high. You can see one at http://www.backyardnature.net/n/17/170730bp.jpg
Something interesting about the young plants is that the first leaves to appear consist of just one blade on a petiole; they're "simple" leaves. But later on, they become "compound" leaves, consisting of three or five leaflets. You can see a three-parted, or trifoliate, leaf -- its purplish petiole pointing toward the left -- at http://www.backyardnature.net/n/17/170730bq.jpg
I knew this plant when I first saw it because it's a common houseplant, and because this species often is brought into biology classes to illustrate an example of "vegetative reproduction." In English is goes by many names, including Air Plant, Life Plant, Miracle Leaf, Floppers, Cathedral Bells, and Goethe Plant. (Goethe really liked it, talked about it a lot, and gave little sprouts to visitors, which I can do, too.) Unfortunately, none of those English names is much good, either because other unrelated plants share the same names, or their use is erratic. Up North, often Bromeliads are known as Air Plants. Anyway, the plant shown in our photos is BRYOPHYLLUM PINNATUM, native to Madagascar, but naturalized and "gone weedy" in much of the world's tropical and subtropical zones.
And now to undo some of the misleading statements made above: The items I've been calling leaves -- to keep from getting bogged down -- aren't really leaves. They're "phylloclades," which are stem branches, more or less flattened and functioning as and often looking like leaves. That explains how the Air Plant's "leaves" can produce new plants along their margins. They're not leaves at all, but rather stems branching and sprouting the way stems are supposed to. Christmas Cactuses consist of phylloclades.
When you see such juicy-looking plants with no spines, stinging hairs, or other obvious defenses, you wonder what's to keep herbivores from feeding on it. The answer is that they are toxic. Bryophyllum pinnatu contains compounds known as bufadienolide cardiac glycosides, capable of causing heart problems in grazing animals.
We've seen that when a plant is toxic, often in small doses it's also medicinal, and that's the case here, at least in traditional medicine. Though the Maya know nothing about it -- it wasn't in the Americas during the formation of the Maya pharmacopoeia -- in various places it's been used to treat hypertension, and its juice to cure kidney stones, though no scientific studies support these uses.
A SECOND ARRABIDAEA VINE
A fairly common woody vine issuing fair-sized flowers with rosy-colored, megaphone-shaped corollas these days is the one shown at http://www.backyardnature.net/n/17/170730bg.jpg
The vine's leaves are compound, sometimes consisting of two leaflets but more often three, like those shown at http://www.backyardnature.net/n/17/170730bh.jpg
The flowers are bilaterally symmetrical, so there's only one way to cut across them that produces mirror images, as shown at http://www.backyardnature.net/n/17/170730bj.jpg
Looking at the flower from the front, you see it nicely designed for pollinators, shown at http://www.backyardnature.net/n/17/170730bi.jpg
In that picture you can imagine a bee landing on the lower petal, seeing whitish stripes directing pollinators toward the nectar deep in the corolla tube's bottom, and as the bee enters, first pollen of other flowers is scraped from its back onto the flower's pale, Y-shaped stigma barely visible in the above picture, and then deeper into the tube anthers clustered at the top dump pollen onto the pollinator's back, to be carried to the next flower. Also in the above picture, at the bottom, notice the curving, slender items. Those are stigma-tipped stiles sticking from the flowers' calyxes after their corollas have fallen off.
The long styles tipped with their Y-shaped stigmas, persisting after the corollas have fallen, is a good field mark, as is a feature seen in the picture showing the flower from the side. There, notice how the corolla at its base diminishes in diameter a little, but not much, as it enters the urn-shaped calyx. Also, that the calyx itself is a little longer than wide. These obscure field marks help separate this species of woody vine from others in this area that are very similar.
We met one of those similar species back at Chichén Itzá. Its web page is at http://www.backyardnature.net/yucatan/arrabida.htm
That vine was Arrabidaea podopogon, one of four Arrabidaea species listed for the Yucatan. Our present species is ARRABIDAEA FLORIBUNDA, distributed from southern Mexico south to El Salvador, and then again in South America.
As with several woody vines in our area, local Maya artisans collect its pliable, woody stems for weaving baskets.
With the return of the rainy season mushrooms and other forms of fungi have appeared. In general the arid Yucatan isn't a good place for mushrooms, but the few species that do develop often are interesting. For example, consider the one about an inch across (2.5cm) found growing on wet, decaying wood, shown at http://www.backyardnature.net/n/17/170730gs.jpg
Nearby, a younger member of the same species displayed an earlier stage of development -- the fruiting body before the outer cover split to reveal the spore-filled, bladder-like central part. This is shown at http://www.backyardnature.net/n/17/170730gt.jpg
From years of paying attention to mushrooms up North, I knew that this was an earthstar, which in rainier areas sometimes are fairly common. Earthstars are essentially puffballs encased in thick skins that, when mature, split so that the parts peel back, as shown in the picture. When the parts are peeled back, reproductive spores are emitted through the hole at the puffball's top.
In general the fungi of Mexico are relatively unknown, so I had little hope of identifying this species. However, it was worth a try. I knew that earthstars are members of the fungus family Geastraceae, in which the dominant genus is Geastrum -- which I figured this one was -- so on the Internet I looked for botanical treatments of Mexican Geastraceae.
Luckily there appeared a 1999 paper in Revista Mexicana de Micología by Evangelina Pérez-Silva and others exactly on the topic of Mexican members of the genus Geastrum. You can freely download this paper in English, in PDF format.
That excellent paper informs us that 14 species of the genus Geastrum occur in Mexico, and there's a technical key for identifying the species. That key quickly directed me to GEASTRUM SACCATUM, known to occur in the Yucatan. A key field mark is the felt-like covering of the outer skin (the exoperidium).
To confirm the ID, on the Internet I looked for pictures of Geastrum saccatum and was immediately led to a good one posted at Wikimedia, at https://commons.wikimedia.org/wiki/File:Yucatan-Earthstar.jpg.
You can imagine how surprised when that turned out to be my own picture taken in Yokdzonot, Yucatán in 2008. In this Newsletter I'd posted it as an unknown species of Geastrum, and someone, someplace, had identified it and posted it at Wikimedia without my knowledge.
Well, this is great, a fine example of people helping one another via the Internet, slowly crystallizing our knowledge about Nature.
By the way, Geastrum saccatum appears to be widely distributed. I find it listed for both North America and Europe, including in northern areas.
THE ROAD TO TEMOZÓN
The road to Temozón is pure jazz. Sunburned old Maya men on black bicycles overloaded with firewood, sleek Cancún tourist buses with Costamaya lettered watery blue, white clouds in blue sky, dog-bark-green slashed-&-burned fields tufted with corn and joyous weeds and skull-white limestone rocks, rainbow roadkill, gray asphalt, sunlight and wind and heat with butterflies, "my" squeaking bicycle pedals needing oil, "my" in quotes because here "I" go again losing "myself," diffusing outward until there's no out, no in, no "me," ¿see? Sí, hee hee. Jazz.
So, in the beginning there was a boxy little white house in the Kentucky farmlands among shadowy Boxelders and Red Maples, dogs named Whitey and Prince, Mama & Daddy, big yellow schoolbus on the gravel road, tobacco fields and soybean fields, a big, falling-apart barn with corncribs and stalls, a white Cumberland Presbyterian church on Church Hill, all Key of C, no sharps or flats, all whole notes, half notes and quarter notes but nothing more, improvisation verboten then: Cymbal clash November 22, 1963/ Vietnam/ Little Rock and Selma kaboom!, and now that thing with all that jazz-with-prelude inside goes trundling down the road to Temozón, and that's jazz, too.
The question arises, then, How does the road to Temozón, and this trundling entity on the road -- both purportedly jazz -- relate?
It's jazz inside jazz.
And there's more jazz than that, like, the jazz of tortillas-and-beans-and-woodsmoke backcountry Mexico wrapping around this jazz of the Road to Temozón, and on up, skipping a lot, the jazz of Earth's photosynthesizing, carbon-cycling, living, dying, rejuvenating biosystem, and more skipping to solar system jazz and all its geometry, gravity fields and alignments, and on to swirling, black-holed, new-stars-forming galaxy jazz, and then Universe jazz that can only be described in poetry, or silence, and it works the other way, too, like, inside the trundler there's this jazz of bacteria and intestinal worms grooving their own universe of digestive enzymes, cosmically streaming nutrients, and inside that bacteria and worms, still skipping a lot, there's amino acid molecules dancing to their own jazz, jitterbugging through semipermeable membranes, jockeying to become proteins, and on down inside the molecules there's jazz of electrons around protons, the electrons' near-speed-of-light weirdness and electrical charges like yin and yang pulling and shoving and making time, and way down subatomic particles' eternal eruptive lightnings pirouetting through their own crazy, cozy universes, jazz inside jazz all the way down and all the way up, and I can even think of sideways jazz but by now you're getting the picture, that, really, it's all just the Big Theme being worked out, the Mother of all Improvisation riffing here and there, in other words that its the One Thing being Herself and, with Her,
Best wishes to all Newsletter readers,
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