January 7, 2018
A GREEN-FLOWERED SARCOGLOTTIS ORCHID
Right beside the trail leading through the woods to the rancho, the trail that surely I've taken a hundred times so far, suddenly something new and unexpected has appeared, shown at http://www.backyardnature.net/n/18/180107sg.jpg
It's an orchid, one I've not seen before. Unlike most orchids, it's growing on the ground instead of on a tree. Its rosette of glossy, variegated basal leaves is striking and somewhat unusual, but it's those green flowers that demand attention. A closer look is shown at http://www.backyardnature.net/n/18/180107sh.jpg
Anyone familiar only with the structure of typical flowers finds orchid blossom anatomy surreal. The most striking orchid innovation is the column, or "gynandrium," formed by the union of the flower's style, stigma and stamens. In the above picture, the flower at the lower, left shows the column doing something strange. It's curving downward to the point that its spreading, flat tip appears to be touching the floor of the broad "lip." A close-up of this is shown at http://www.backyardnature.net/n/18/180107si.jpg
I'd like to know how this construction functions, but just can't find literature explaining it. My guess is that pollinators land on the broad lip, and in trying to pass beneath the column to reach sweet-smelling nectar, somehow accomplish pollination.
In terms of evolutionary history, the Orchid Family is one of the most recently arisen families. In accordance with general evolutionary trends, the family has explosively produced an amazing diversity of species -- it's the most species-rich of all plant families -- while at the same time integrating parts. Our flower's column formed by the union of the flower's style, stigma and stamens is an example of that trend toward integration and fusion.
However the flower's curved column works, our orchid is SARCOGLOTTIS SEPTRODES, native throughout most of Mexico's humid lowlands, and through much of Central America. It's uncommon, but not regarded as a threatened species on a national level.
A ROBUST, WEEDY, GORGEOUS ORCHID
Last October during the middle of the month when I visited my gardening friend near Tepotzlán in upland Morelos state, in the volcanic belt just south of Mexico City, on the steps leading to my room a potted orchid was putting on a show, as seen at http://www.backyardnature.net/n/18/180107ep.jpg
My friend said the plant had been rescued from a nearby scrubby area with volcanic boulders atop the volcanic ash, were development was rapidly encroaching, so it was part of the local flora. Unlike many orchid species that grow epiphytically on trees, this species was terrestrial. Its being native here probably explains why it was successful in producing the healthy looking fruits shown at http://www.backyardnature.net/n/18/180107eq.jpg
But of course the plant's most striking feature are its flowers, a close-up of one shown at http://www.backyardnature.net/n/18/180107er.jpg
This is EPIDENDRUM RADICANS, commonly known as the Ground-rooting Epidendrum, Fire-star Orchid, Rainbow Orchid, Reed-stem Epidendrum, and other names. It's a common roadside weed at middle elevations in Mexico and Central America. You might be interested in seeing what it looked like when we found it along a weedy road in high elevation Chiapas in southernmost Mexico at http://www.backyardnature.net/chiapas/o-e-radi.htm
Plant ecologists sometimes speak of a complex of red/orange-flowered, weedy species that are unrelated but ecologically similar. Along that roadside in upland Chiapas where I photographed Epidendrum radicans in the wild, there also grew the Tropical Milkweed (Asclepias curassavica and Wild Sage (Lantana camara), both species with red and orange flowers that at a distance might be confused with Epidendrum radicans. It's been shown that species within this complex share pollinators as well as habitat, possibly exhibiting "convergent evolution," which is where unrelated species "converge" by developing similar physical features under similar evolutionary pressures.
SCHWENKIA, VERSION 2
In a densely weedy, shaded thicket at the rim of one of the rancho's sinkholes, or cenotes, a certain spindly looking herb turned up looking too delicate to compete with such coarse weeds as surrounded it. It was so embedded within the vegetation that only parts of the plant could be seen at one time. The diffuse, sparsely flowered inflorescence that had caught my eye is shown at http://www.backyardnature.net/n/18/180107sw.jpg
Notice the very slender, purplish flowers at the top, and the ovoid, capsular fruits at the bottom. We've seen Gerardia/Agalinis species with such wide-open inflorescences and similar fruits, but this plant's flowers are all wrong for that. When I sought clarification by looking for leaves down below, what I found turned out to be fairly characterless, as shown at http://www.backyardnature.net/n/18/180107sx.jpg
A fruit close-up revealed nothing special, either, as seen at http://www.backyardnature.net/n/18/180107sz.jpg
So, back to that skinny flower, shown close-up at http://www.backyardnature.net/n/18/180107sy.jpg
What plant families can produce capsular fruits, alternate leaves with no lobes or serrations along their margins, and tubular flowers like these? There's the Figwort or Snapdragon Family to which Gerardia/Agalinis belong, but flowers in that family usually are asymmetrical, or "irregular," while these are regularly symmetrical. Still, I reasoned, this species must be in a family close to the Snapdragon Family.
On the Phylogenetic Tree of Life, the Snapdragon Family stands next to the Black Nightshade or Tomato Family. When I remembered that, I remembered something else, too: I've seen this plant before, and also then I'd had a hard time figuring out what family it belonged to. And though that earlier plant had borne identical flowers and fruits, it had occupied a different environment, and presented a completely different overall appearance. You can see what I mean on our page for that earlier plant at http://www.backyardnature.net/mexnat/schwenck.htm
So, this is Schwenckia americana, which for want of a better name we just call Schwenkia.
One feature of the plant not already detailed on its page is Schwenkia's medicinal value. The Black Nightshade Family, or Solanaceae, to which the species belongs is famous for its species often containing powerful compounds that deter animals from feeding on the plants. In fact, research in the 1960s confirmed that Schwenkia has an interesting brew of alkaloids, glycosides, something called schwenckioside, and sapogenins. The sapogenins displayed effects on the heart. Also, simple water extracts of the leaves showed antimicrobial activity toward certain disease-causing organisms.
Therefore, it's not surprising that traditionally in various cultures the plant has been used for a variety of ailments, including to cure coughs and other lung problems, as a purgative, against intestinal worms, headaches, sinus problems, conjunctivitis, swellings, arthritis, stomach disorders, hernias, gonorrhea, measles, chickenpox, athlete's foot, fever... the list goes on and on.
In keeping with the observation that often compounds that are medicinal in one dosage are toxic at higher concentrations, in some places the whole plant has been pounded to pulp for use as fish poison.
At Genesis Eco-lodge often they serve portions of cubed Jackfruit fruit, the fruits being bought in local stores. Jackfruit fruits are big things, reaching 2ft long (60cm) and weighing up to 40lbs (18kg). They look a lot like Breadfruit and Breadnut fruits. Some young Breadnut fruits are shown growing on a tree in Chiapas at http://www.backyardnature.net/chiapas/artocarp.htm
The Breadfruit, Breadnut and Jackfruit species all belong to the same Fig-Family genus, Artocarpus. it's ARTOCARPUS HETEROPHYLLUS. In Chiapas I've seen many Breadnut trees planted but never any Jackfruit, so when the lodge's owner, Lee, gave me some seeds to plant, I thought that maybe they were really Breadnut seeds.
However, I planted them -- the seeds had been recently removed from a big fruit that was eaten on the spot -- got an excellent germination, and now the seedlings bear two or three leaves, and the leaves look more like Jackfruit than Breadnut leaves. You can see a seedling in a pot at http://www.backyardnature.net/n/18/180107jf.jpg
Getting the seeds to germinate was very easy, but now the seedlings' leaves seem to be infected with a kind of brown spotting, probably of fungal origin, so we'll see how that develops. I'm hoping that a future entry here will document the plants' first flowers and fruits.
OWL PEEPS TRENDING TOWARD JOY
Nights right before and after the Winter Solstice are the longest of the year, which means more when you're without electricity and go to sleep when the sun goes down, and get up with dawn's first light. During these few chilly nights of the year I awaken a bit before dawn and just lie there, enjoying the sleeping bag's toasty coziness, and the quietness.
The first sound of the approaching dawn often is the Ferruginous Pygmy-Owl's monotonic and long-running series of simple weep-weep-weeps, issued from beside the hut. A child just learning to whistle can imitate the call well enough to entice the bird closer. And the call just goes on and on. Before long a slightly less monotonic but just as monotonously repeated call wafts in from a distance, a nasal wah wah wah... that also goes on and on, the call of the Laughing Falcon. This call is a little more interesting if only because during certain seasons -- not now -- the wah wah wah... sometimes rises in pitch and breaks into a cackling series of fractured caws that really can sound like someone laughing.
The next bird that may start calling continues the trend toward polyphony and complexity, for it's the Turquoise-browed Motmot with a funny-sounding croaking kind of call, maybe like a frog being stepped on.
As dawn's first light begins to suffuse the darkness, other birds chime in, all of them with more variable and interesting calls than those preceding them -- the Black-headed Saltator's "gruff, accelerating, rolling laugh or chortling chatter," as Howell describes it. Then there's the Melodious Blackbird, and others, reaching some kind of lush aural climax just before the sun's actual rays flood in from the east. That's when Chachalacas strike up their uproariously loud, raucous screeches, which I've captured in a WAV audio file at http://www.backyardnature.net/n/11/chacha.wav
Lying inside my mosquito net hearing all this, one thought that comes to me quite often is that this progression of morning birdcalls from simple and monotonous to complex, rousing and possibly even hilarious as well as beautiful and inspiriting -- echos the evolution of the Universe itself, from Big Bang, to what we have now. And the same kind of evolution can be observed in many of the Universe's more interesting subsets, such as Life on Earth, and the development of human mentality.
With this insight floating in the background, one morning this week I was thinking about the matter that for a long time often I've described the evolution of the Universe as generally trending toward ever greater diversity of parts that are ever more complexly interrelated and interdependent.
That word "interdependent" has always jarred me a little -- even though it's true. Maybe the word jars because by nature I personally like to be dependent on as few others as possible, and I see nothing wrong or retrograde about being like that.
Moreover, the gradually evolving chorus of birdcalls heard these mornings -- which I imagine to echo an evolutionary pattern similar to that of the continually evolving Universe and its major subsets -- seems to make no reference to interdependency. The birds' symphonic climax sounds good-natured, unreservedly ebullient, even joyous, with the only connection with interdependency being in the mind of the beholder. It's the mind that understands that without the various birdcalls on some aesthetic level depending on other birdcalls in the community's to be harmonious with their own call and the environment, what's heard instead of being beautiful is just noise. Interdependency simply happens, with natural evolution taking care of the details.
Maybe the lesson here is that if we are to form communities as agreeable to live in as it is to hear birdcalls on a dewy morning in the Yucatan, there's no reason to concern ourselves with consciously structuring the community for interdependency among its citizens. Just be ourselves, and if we are true to ourselves, then interdependency, or community, results, and it is beautiful.
Best wishes to all Newsletter readers,
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