March 4, 2012

LACEWING EGGS HATCHING
Just last week we looked at a dead lacewing floating in a forest pool near the Hacienda. This Wednesday at 8 AM, on the upper surface of a leaf of an Elephant-Ear plant beside the hut, a white splotch caught my eye. Up close the smudge showed itself as what's seen at https://www.backyardnature.net/n/12/120304lw.jpg.

That's a view from directly above a cluster of stalked lacewing eggs -- stalked because the lacewing's newly hatched larvae are so hungrily predaceous that if they can get at their siblings they'll eat them.

In the picture, the eggs' slender stalks show up as shadows. The picture also shows something I didn't notice while working with the camera: On their lower sides, most eggs bear something white and hairy. A shot pushing my camera and Photoshop to their limits better shows what the hairy things are at https://www.backyardnature.net/n/12/120304ly.jpg.

The hairy things are larvae just hatched from the eggs, the larvae's bent legs clasping the egg shells they've just emerged from. Spreading hairs arise from atop each larva's back. A side view of the same is at https://www.backyardnature.net/n/12/120304lx.jpg.

Not to go unnoted in these pictures is that only a very few eggs do not bear larvae. These pictures answer the question of whether in this lacewing species eggs hatch at the same time -- are synchronous.

Also, seeing the hairs atop each larva's body, we remember a lacewing larva that fell from a tree onto us one summer back in Kentucky. Its body had been covered with lichen flecks, as camouflage. Maybe our current larvae will similarly attach pieces of camouflage to their own hairs.

My surprises weren't over yet. At about 10:30, as it was starting to get pretty hot and the sun bore down with great intensity, I went back to see if larvae might be found wandering the Elephant-Ear's big leaf. I found no larvae, but where the stalked egg cases should have been I found what's shown at https://www.backyardnature.net/n/12/120304lz.jpg.

It looks like all the stalks and egg cases melted together!

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AVOCADO TREES FLOWERING
Along the backstreets of Dzitas, a little Maya town maybe 20 minutes by car north of Pisté, branch tips of Avocado trees are loaded with diffuse, basketball-size panicles of small, yellowish flowers as shown at https://www.backyardnature.net/n/12/120304av.jpg.

Up close, the blossoms reveal several interesting features, as seen at https://www.backyardnature.net/n/12/120304aw.jpg.

Avocado trees, PERSEA AMERICANA, are native tropical-American members of the Laurel Family, the Lauraceae. The above picture shows several features common to flowers in that family. (Other Laurel Family members Northerners might be familiar with include Sassafras, Spicebush and the Laurel itself.)

Flowers in the Laurel Family normally are yellow or greenish, with no corollas or petals, which is the case with this flower. In the picture, the fuzzy, petal-like things spreading from the flower's center are calyx segments adapted to visually attract pollinators, a job more commonly handled by a flower's corolla. The calyx has six lobes, but notice how the lobes overlap; at the left, one lobe practically lies atop another. This overlapping of sepals also is a Laurel Family characteristic.

In the picture, the slender thing with a bulging top pointing toward the picture's top, right corner is a stamen. In the Laurel Family, stamens are arranged in three or four "whorls" -- an outer ring of them, an inner ring, and one or two rings inside those. In the picture at least two stamen whorls are recognizable. Notice the orange things at the base of some of the stamens. Those are "staminodia," or modified stamens, representing one of the whorls. I'm not sure what the staminodia do here; maybe their bright color helps attract pollinator toward the flower's center.

Also notice the curious flap-like items atop each stamen's anther -- the anther being the baglike thing in which pollen is produced and later released. In the Laurel Family, anthers lose their pollen through holes left by uplifting "valves." Those flap-like things atop the anthers are uplifted valves, and this curious construction also is a Laurel Family curiosity.

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RAMÓNS FLOWERING
At https://www.backyardnature.net/mexnat/ramon.htm we've documented a lot about the nutritious and tasty fruits of the Ramón tree, BROSIMUM ALICASTRUM, which grows here. Now the Ramóns are flowering, as shown at https://www.backyardnature.net/n/12/120304ra.jpg.

Those spherical, yellowish things are clusters, or inflorescences, of tiny flowers. One cluster is shown at https://www.backyardnature.net/n/12/120304rb.jpg.

Anyone familiar with how flowers are supposed to look will have a hard time figuring out what's being seen in that picture. Since Ramóns belong to the Fig Family, and fig flowers are famous for being weird, we shouldn't be too surprised.

First, nearly all the flowers shown in the last picture are male, with no calyx or corolla, and bearing only one stamen instead of the usual several. Each stamen bears a baglike, pollen-producing anther atop its filament. Unlike any other anther I can remember, the Ramón flower's anther is shaped like a mushroom with a stem connecting with its cap more or les in the cap's center -- it' "peltate." This strange anther is about 1mm wide.

Not easy to make out in the picture are the one or two female flowers at the cluster's center. Female flowers bear deeply two-lobed stigmas, which extend from the inflorescence 4-7 mm before the male flowers open. In other words, the Ramón's female flowers mature before its male ones, which makes self-pollination much less likely.

By the way, while photographing the above flowers I had to admire a Ramón twig's stipular ring, shown at https://www.backyardnature.net/n/12/120304rc.jpg.

Woody plants of the Fig Family normally bear such rings. Stipules are modified leaves that fold over very young twigs and leaves as they are emerging. Once the young parts grow tough enough, usually but not always -- depending on the species -- the stipules fall away, leaving a stipular scar. In the picture, the scar arises at the bottom of the green bud in the picture's center, and continues to the lower, right, all the way around the twig, encircling it, thus becoming more than a mere stipular scar; it's a stipular ring.

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STAR-APPLES FRUITING
Already we've looked at our handsome Star-Apple trees, known here as Caimitos, but only in rainy August when the trees were flowering. Our Star-Apple page is at https://www.backyardnature.net/yucatan/starappl.htm.

At https://www.backyardnature.net/n/12/120304ch.jpg you can see ripe, purple-skinned, 3½-inch-across (9cm) fruits currently hanging on a tree in Dzitas. Even if you don't recognize the fruits, the tree's leaves, so green and shiny on top and richly golden-brown below are so distinctive that Star-Apple trees are easy to recognize.

The fruits contain a translucent, whitish pulp surrounding three to eight shining seeds.

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CALAGUALA FERN
In an abandoned lot on a backstreet of Dzitas, several Huano Thatch Palms cast cool, pleasing shade. On Huano trunks, the stiff petioles of old fronds remain long after the fronds have broken off, making the trunks look bristly and raggedy. Over time, organic and inorganic detritus collects in the angles between the old petioles and the trunks, forming a kind of soil. Plants can root in that airborne palm-trunk soil, animals can take up residence there, and other organisms can come to create whole palm-trunk ecosystems.

On this particular backstreet in Dzitas, most older Huano palm-trunk ecosystems hosted a fern species I've not seen elsewhere in the Yucatán, as shown at https://www.backyardnature.net/n/12/120304fn.jpg.

Luckily, several frond segments bore spore-producing sori, or "fruit dots," needed for identification, seen at https://www.backyardnature.net/n/12/120304fo.jpg.

Not many kinds of ferns have their sori scattered across their fronds' broad undersurfaces like that. Among ferns up North the only ones with sori looking a little like this are the Polypodies, genus Polypodium. In fact, our Huano-trunk fern species has sometimes been placed in the genus Polypodium, but nowadays most experts assign it to Phlebodium -- it's PHLEBODIUM DECUMANUM.

And that's interesting because I don't find Phlebodium decumanum listed for the Yucatán. It occurs from southern Mexico south deep into South America, but I am surprised to find it growing under such relatively arid conditions as here.

Finding Phlebodium decumanum here also is interesting because its fronds and rhizomes are regarded by many as medicinal. However, there's little agreement about what they're medicinal for. You can find claims that they're good for everything from whooping cough and fever to joint pain, blood needing cleansing, dermatitis, problems of the pancreas... on and on.

But, maybe there's something to the claims. Clinical research involving various double-blind placebo human trials found that a water extract from the fern was "an effective treatment for psoriasis --as well as dermatitis and vitiligo (with a 3-6 month course of treatment required)."

A common Spanish name for the fern is Calaguala. In Brazil they call it Samambaia. Medicines based on the fern are often marketed under those names.

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A FERN PROTHALLUS
Speaking of ferns, as I walked past the Hacienda's water cistern I paused to nose in a patch of moss on the cistern's shady side. One thing I saw is shown at https://www.backyardnature.net/n/12/120304pr.jpg.

Here we're witnessing the "birth" of a Roughhairy Maiden Fern, THELYPTERIS HISPIDULA, which we profile at https://www.backyardnature.net/yucatan/rufhairy.htm.

What's interesting is that the reproduction of ALL ferns is not as simple as the fern frond producing spores, which then germinate to form new ferns. Fern reproduction is bizarre. It's almost as if human females should give birth not to human babies, but to dog pups. The dogs would then mate, but the female dog would give birth not to a baby dog, but to a baby human. And then the cycle would continue, human, dog, human, dog... Here's how it works in ferns:

When a fern spore germinates, what develops from the spore is not a fern frond, but rather a flat, more-or-less heart-shaped item about the size of a baby's thumbnail, known as a prothallus. A diagram of one is provided at https://www.backyardnature.net/fernprot.gif.

In that diagram, rhizoids are basically roots. The antheridia produce male sex germs, and the female sex germs reside in the archegonia. When male sperms swim through dew or rainwater to a receptive archegonium, fertilization takes place, and then the thing we think of as the fern -- the collection of fronds with their stems and roots -- sprouts from a fertilized archegonium. This sprout eventually matures and produces spores, and when the spores germinate, another prothallus is produced, and the cycle continues.

In our picture, the flat prothallus lies at the top of the picture. Two sprouting fronds emerge from an archegonium on the prothallus' underside, their stems passing between the prothallus' two lobes.

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A RANGY, MYSTERIOUS GARDEN PLANT
Along one of Dzitas's little backstreets a bush with a grossly oversized flowering head showed up, as seen at https://www.backyardnature.net/n/12/120304po.jpg.

Toward the bottom of that picture notice that at least some of the leaves are trifoliate -- compound, composed of three leaflets -- and that the leaflets are roundish on long stalks, or petiolules (leaf stalks are petioles, leaflet stalks are petiolules). Also notice that though the inflorescence was enormous for a plant of that size, the flowers were tiny and grouped in small, spherical heads, which in turn were clustered umbel-like at the end ends of sprawling stalks (rachillas), which themselves arise at the ends of long, flaring rachillas. The inflorescence must still be growing, for its tiny flowers only now are beginning to burst from their buds, as shown at https://www.backyardnature.net/n/12/120304pp.jpg.

A close-up of a single blossom is shown at https://www.backyardnature.net/n/12/120304pq.jpg.

So, what is this plant? I was standing scratching my head when I noticed the señora standing in her hut door looking at me smiling, so I laughed and called to her, asking if she knew a name for this strange plant. She came out followed by kids, wiping her wet hands on her dress, and with a serious look that suggested that she's often wondered the same thing, told me that she just didn't know. Neither did she know what it was good for or how it had found its way into her front yard.

Back in the hut, I had a hard time "doing the botany" because first off I made a mistake. Seeing the compound leaves and, more importantly, how its tiny flowers were grouped into umbels or umbel-like clusters (an umbel being a flower cluster with its flower pedicels arising from a common point, like the stays of an umbrella), I assumed that the plant was in the Parsley or Carrot Family, the Umbelliferae (now often known as the Apiaceae). However, after a lot of searching in that family nothing turned up like our mystery plant.

Then I remembered: In the past I've been fooled several times by plants in the Aralia or Ginseng Family, the Araliaceae, which is very closely related to the Parsley Family. The fruits of the two families are different, but we don't have fruits here. In general, however, species in the Aralia Family are more woody than those of the Parsley Family, plus flowers of the Aralia Family usually bear more than two styles, while flowers of the Parsley Family have only two. And in our flower picture you can barely see three styles atop the little green ovary in the blossom's center. So, we had an Aralia Family member here.

The Aralia Family is much smaller than the Parsley Family, which helped with the identification process. Members of the Aralia Family Northerners might be familiar with include Ginseng, English Ivy, Devils-Walking-Stick or Hercules Club and Spikenard. Our Dzitas plant is a member of the genus Polyscias, and if I had to bet I'd say it's POLYSCIAS SCUTELLARIA, which goes by several poorly established English names, including Round-leafed Polyscias, Shield Polyscias and Dinner-Plate Polyscias. It's native to the South Pacific.

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THE GRINNING MOON
The other night I was walking with my Estonian lady-friend Malle as a slender crescent of the Moon set in the west. Suddenly Malle stopped, looked hard at the Moon, and said it didn't look right. New Moons like this one ought to hang crookedly in the sky, she said. Their crescents should tip to one side like a bowl pouring out its water. But this Moon was hardly tipped at all. It was like a big smiley-face grin, its mouth corners about equally high. You can see that very Moon at https://www.backyardnature.net/n/12/120304mn.jpg.

Of course my picture doesn't prove much, since I could have held the camera at any angle, placing the Moon in the picture in any position. I can only say that I tried to hold the camera horizontally.

When I started thinking about the issue, it also seemed to me that the new Moons of my childhood back in Kentucky were angled, not smiley like this one.

Finally I got it worked out.

The waxing Moon in the picture is setting in the west. Facing it, north is on our right. If we were to start side-stepping to our right, heading northward, eventually the Earth's curvature would cause our bodies to tilt northward, causing the Moon in the sky to seem to tilt the way Malle remembered it. Malle is from Estonia, which lies very far to the North, so the new Moons she remembers would be much more tilted than my Kentucky Moons. If that night Malle and I had been standing at the North Pole, I guess the Moon would have been tilted completely onto one side, standing on one of its cusps!

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FLÂNEURING IN DZITAS
Last Sunday Newsletter readers Eric and Paul visited from Mérida. One of the much appreciated gifts they brought along was a book, The Nature of Nature, a hefty, 963-page, 2011 compilation of essays by the world's foremost experts in the very things we like to think about here. What is Nature evolving toward? How does human brain function affect our perceptions and thinking about Nature? In fact, what is awareness? And "being"? And, what does it all mean? Among the book's essays were those dealing with the string theory, consciousness and neuroscience, quantum interactive dualism, and eternal inflation.

I parked the book on my table and then the three of us plus my friend Malle went up to Dzitas, a little Maya town maybe 20 minutes north by car of Pisté. The idea was just to walk down Dzitas' backstreets the whole morning gawking at plants in people's backyards, pigs and turkeys, cute kids, the local sinkhole. Along the way Paul introduced me to the French word flâneur, which means, approximately, "to wander aimlessly, relying on serendipity and an open mind and heart to make it a good experience."

We saw a man high in a Ramón tree with his machete cutting branches for his horse to eat; in a shop another man carved a stone flowerpot. Little girls peeped around hut corners and sometimes the fragrance of orange blossoms mingled with dust and the odor of wood ashes and pig manure. A little boy on his house's roof flew a homemade white kite, and all around that house other homemade white kites hung tattered and flapping among tree branches, each one with its own story.

Our flâneuring in Dzitas finished, back in the hut, in the big book on the table I gravitated to an essay by Christian de Duve, Professor Emeritus at both the University of Louvaine and Rockefeller University. He addressed the question of whether in Nature, beyond the uninspired, mechanist inevitability of the way things of physics and chemistry automatically interact and evolve there's "Something Else" -- something giving direction to evolution, something rejoicing when thinking beings gain insights and feel, something we might call The Creator, or God.

All the book's essays ended with formal conclusions so I turned to the conclusion of de Duve's essay to see what his great mind with access to all the latest theories and the most up-to-date data from experiments in all fields of science might conclude about this "Something Else" and the human condition. He wrote, using the pronoun "we" to mean "we humans":

"We are entitled to see ourselves as part of a cosmic pattern that is only beginning to reveal itself. Perhaps some day, in the distant future, better brains than ours will see the pattern more clearly."

So, in 963 pages of the most profound data crunching and struggling for insight, humanity's sages seem to be no clearer about "What's really going on here?" than are most of us who just stumble around in the woods, work in our gardens, and gaze into the sky.

Today, with the gentle feelings of our Dzitas flâneuring still buzzing inside me, and the heavy feeling of the big book still remembered by my hands, here is exactly what I think:

What is the basic human condition? It is a little boy flying his kite from a rooftop, with kite-eating trees all around, but the trees themselves are more beautiful than any kite.

What is the meaning of it all? It is the odor of Orange blossoms mingled with pig manure, carried by the wind that knows only to yield, yet touches everything, and would never presume to even ask such a silly question.

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PAUL'S BLOG
By the way, Paul, the flâneuring-word friend, posted a very nice, well illustrated blog about our walk at http://hammockmanpaul.blogspot.com/#!/2012/02/naturalist-jim.html.

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Best wishes to all Newsletter readers,

Jim