October 26, 2018
"VINE PALM"
This October 1st, during my camping trip in Guatemala's northern Petén region, I was walking along the road through El Rosario National Park on the east side of Sayaxaché when a bush growing among lots of weeds caught my eye. Most of the bush was hidden by weeds, but you can see its top at https://www.backyardnature.net/n/18/181026dc.jpg
The bush's pinnately compound leaves were about six feet long (2m). That's one thing that had gotten my attention, but what really stands out in that picture are those long, slender items rising vertically from the bush's center. The same kind of slender things also terminated young leaves growing outwardly, as shown at https://www.backyardnature.net/n/18/181026dd.jpg
In that picture it's clear that the slender items are immature extensions of the leaves' still-developing midribs. The backward-pointing growths are leaflets gradually modifying into spines toward the midribs' tips. At the leaf's tip, there's just backward-pointing spines. Just as unusual as all this was the bush's pliable, slender stem, shown at https://www.backyardnature.net/n/18/181026de.jpg
The black, needlelike spines are similar to those found on certain palms, and in fact here we do have a palm. And this palm species is famous less for being spiny than for being viny. Young trees start out growing erect, but as they mature they lean and wander, climbing up through thickets of trees or bushes to 40ft or so (12m). And thickets is usually where you see them, especially along disturbed lake shores.
This memorable palm is DESMONCUS ORTHACANTHOS, native from southern Mexico south through Central America to Brazil and Bolivia in South America. The Yucatan is too arid for them. There's no good English name for the species.. In Spanish sometimes it's called Palma Bejuco, which simply means "Vine Palm."
The backward-pointing spines at leaf ends -- technically known as cirri -- serve as hooks anchoring the plant among its neighbors as it climbs upward. Traditionally fiber from the stems has been used for baskets when nothing better was handy.
The world of palms is so large and diverse that sometimes it's hard to identify them to species level. This palm was easy, even lacking flowers and/or fruits.
*****
PANAMA RUBBER TREE
During my recent camping trip south to El Rosario National Park, on Sayaxaché's east side in northern Guatemala's Petén department, as I explored the campground's perimeter on October 1, I came upon the tree trunk and sign shown at https://www.backyardnature.net/n/18/181026cs.jpg
The sign says that it's the Rubber Tree, CASTILLA ELASTICA, a member of the Fig Family, the Moraceae, and that it's used for making xylophone drumsticks and rubber balls.
Historically and botanically, this is an important tree, one not occurring in the Yucatan's semiarid forests, and I was glad to meet it. The tall tree -- they can grow up to 100 feet tall, exceptionally to 200 ft (30-60m) -- didn't appear to be flowering or fruiting, but at least the camera's telephoto lens could show us its leaves glowing in sunlight far above, shown at https://www.backyardnature.net/n/18/181026ct.jpg
In the forest, these fair-sized leaves are easily recognizable because of their oblong shape becoming a little larger toward their apexes, plus the rounded lobes at the blades' bases, and the ±straight, close-together secondary veins creating a "herringbone pattern." And if we could reach up and make a little tear along a leaf's margin, most likely white latex would ooze from the severed veins, as with most members of the Fig Family.
This isn't THE Rubber Tree, Hevea brasiliensis, from which early car tires were made, and for that reason in English we usually call our Guatemalan species the Panama Rubber Tree. Hevea brasiliensis, belonging to a different family, the Euphorbia Family, doesn't occur in our part of the American tropics, but our Panama Rubber Tree is broadly distributed in rainy tropical lowland areas from southern Mexico south through Central America into northern South America. Our tree has been used to make rubber, too, though the rubber is considered inferior to that derived from Hevea brasiliensis.
Though our tree's inferior rubber has seen days when it was exploited commercially, its greatest claim to fame may be that back when Mesoamerican indigenous people were playing their famous life-or-death ballgames, the balls they used were made from the milky-white latex of Panama Rubber trees. Interestingly, the tree's milky latex was coagulated into usable rubber by mixing it with juice from the commonly occuring morning-glory vine we call Moonflower, shown at https://www.backyardnature.net/mexnat/ipomoea.htm
*****
PICA-PICA FLOWERING
During my recent camping trip south, on October 2 as I hiked along the highway running through El Rosario National Park, on Sayaxaché's east side in northern Guatemala's Petén department, some items dangling from a tree, on long, slender, stringlike things, caught my attention. They're shown at https://www.backyardnature.net/n/18/181026mc.jpg
The dangling items were too high up to show any details, but the camera's telephoto lens revealed what's shown at https://www.backyardnature.net/n/18/181026md.jpg
So, it's a dense cluster of flowers, with only one blossom fully open, but that one flower with its expanded upper petal (the standard), two side petals (the wings) and with its two lower petals fused together along their common borders to form a scoop-like structure (the keel), the plant producing the cluster reveals itself as a member of the gigantic Bean Family, the Fabaceae.
In 2016, in neighboring Chiapas, southern Mexico, we encountered very large legumes covered with irritating hairs dangling on similarly long, slender peduncles. That was Pica-Pica, Mucuna argyrophylla, so could this possibly be the cluster of flowers that proceeds that species's fruits?
Many plants bearing stinging or irritating hairs are called Pica-Pica, because the name says that the plant "pricks" or stabs you, and lots of plants do that. However, Mucuna argyrophylla is endemic only to southern Mexico (not in the arid Yucatan), Guatemala and El Salvador. As such, on the Internet I couldn't find good pictures of the species's Mucuna argyrophylla. However, there was a word description of them, listing these features:
# calyx with short, blunt or rounded lobes
# calyx "silky" with dense, slender, closely held hairs
# flower greenish, yellow or tinted with lavender
# flower's wings as long as the standard, but the keel much longer
# keel rounded at its apex
Our flowers match this description perfectly, plus there just aren't that many Bean Family vines producing flowers and fruits on such long-dangling peduncles, so even without seeing a Mucuna argyrophylla blossom, I'm pretty sure that that's what we have here. Also, there's no reason for it not to be Mucuna argyrophylla, since that species commonly occurs throughout its limited distribution, and the Petén is in the center of its distribution area, and we were in the right habitat.
Flowers in the genus Mucuna usually are pollinated by bats.
Traditionally an excellent black pigment used to paint handicraft was made by mixing an extract from Mucuna argyrophylla seeds with alum and crushed insects called aijshi, whose formal name I can't find on the Internet. Several Internet pages say that the "scales" of aijshi are used, but I think that that must be an error. In southern Mexico scale-like cochineal bugs on pricklypear cacti traditionally were farmed to produce an exceptionally bright red dye, so I bet that that's what they're talking about. Our page on cochineal bugs is at https://www.backyardnature.net/n/a/cochinea.htm
*****
PASSION FRUITS/ MARACUYA RIPENING
The rancho's Maya worker Juan brought me a handful of passion fruits he'd just taken from our vine, calling them by their local name, maracuya. Our Passion Fruit page showing both the good-tasting fruits and the vine's spectacular flowers is at https://www.backyardnature.net/yucatan/passion.htm
When I cut the fruits open, they were all empty, just the fruit's covering with some white pulp. He'd harvested the fruits way too early. However, before throwing the empty shells into the compost, I looked closely at the inside-facing surface of the pulp, and saw that the surface was covered with very tiny, cream-colored, grainy things, as shown at https://www.backyardnature.net/n/18/181026pf.jpg
The cream-colored grains are ovules, ovules being a fruit's future seeds. Ovules occur in ovaries, which mature into fruits, so it's unusual to see ovules in an immature fruit this far advanced. I don't know whether the ovules have been aborted, maybe because of the lack of a proper pollinator, or whether this is normal. We don't have enough fruits for me to settle the matter.
Still, it's interesting that the ovules are clearly attached to the fruit's pulpy wall by white, columnar "funiculi," which are the plant equivalent of animal's umbilical cords. When ovules are borne on the side walls of an ovary, the placentation is described as "parietal," and parietal placentation is a little unusual in the world of flowering plants. When you're identifying a plant and see that its ovary or fruits display parietal placentation, you can narrow down your options very considerably.
The Passion-Flower Family, the Passifloraceae, is one of those few families with parietal placentation, along with the Papaya, Flacourtia, Violet Families, and a few others. You might be interested in seeing the different placentation types in our altered copy of a drawing from my old Baileys Manual of Cultivated Plants at https://www.backyardnature.net/n/18/180928bi.jpg
*****
MILPA UPDATE
At https://www.backyardnature.net/n/p/180720.htm you're introduced to the traditional cornfield, or milpa, produced by an old local Maya fellow who, unlike many local farmers, refuses to halfheartedly tend his field, leaving out the traditional beans and squash, because they're just doing it for the government subsidy. At the above link, you can see what the recently planted cornfield looked like this June.
Last month we saw that the ears were maturing, and that the raccoon-like Tejones and birds were ravaging the crop. Still, a good crop seems to have been produced. Nowadays the cornstalks are brown, and the old man has walked through his cornfield breaking over every stalk so that the ear-bearing upper part hangs downward. This way, when it rains, the corn inside the ear will be better protected by the downward-pointing husks. You can see what this looks like at https://www.backyardnature.net/n/18/181026mp.jpg
In that picture, notice the squash/pumpkin vines working their ways across the cornfield's floor. Early in the rainy season the rains failed for a couple of weeks and the beans he'd planted died, but the squash and corn survived.
*****
TEACHINGS OF THE TWO-TONED EYE
About a year and a half ago my profound nearsightedness and cataracts got so bad that one eye was functionally blind. I had the natural lens removed and an artificial lens installed, returning my vision in that eye to 20:20. A few months ago, for that eye things became a little blurry again, then within the last month it got very blurry -- and my other eye, never treated, was much worse. I was sure that that one eye was becoming blind again, especially because when I looked at it in a mirror, the usually blue-gray iris had developed a brownish band around the pupil. What could the brownness be but dying or dead iris cells? You can see my two-toned eye at https://www.backyardnature.net/n/18/181026ey.jpg
So, last week in Mérida my Mexican ophthalmologist had a look at the eye. After the examination we hopped into his sports car, zipped across Mérida to a big building holding very fancy equipment shared by the community's doctors, and he zapped the rear side of my artificial lens with several laser bursts. Almost instantly in that eye I could see as clearly as ever, maybe better. The brown eye-ring hadn't meant anything.
What had happened with my eye happens in 10-15% of the cases, I was told. Behind the artificial lens, a kind of organic dust or paste forms, refracting light the way the rough surface of scoured glass causes opaqueness. At the laser's focal point at the lens's rear, the particles heat to they point that they explode. The resulting intense heat and concussion vaporizes neighboring particles, leaving the lens's surface pristine. At least that's the way I understood the doctor's explanation.
Fixing my vision so quickly seemed magical, just like when the artificial lens earlier cured the eye's blindness.
But, of course, it wasn't magic. It was science bearing fruit, the results of theory making, experimentation, data analysis, testing, and sharing results with colleagues and the world. It was beautiful, and my life is profoundly enhanced because of it.
Many folks my age have benefited from medical science much more than I. Still, I've been thinking a lot about my somewhat bionic state.
To me, having artificial parts installed in my body seems both natural and harmonious with what appears to be the general direction of the Universe's evolution. For one thing, the evolution of the Universe -- at least as witnessed here on Earth -- surges toward an ever greater diversity of ever more intricately interrelating parts. Finding myself adding to that diversity by becoming something relatively new -- partly organic and partly not -- and benefiting from science that evolves faster and faster to ever higher levels of sophistication... harmonizes with the Universal evolutionary flow.
So, since regaining clear vision, not only have I been enjoying a flush of appreciation for science and people who share what science has taught them, but also I've enjoyed a growing sense of family with the rest of the evolving Universe.
This feeling fits nicely with the notion that, in the end, there's only One Thing, with us particles of consciousness and feeling being the One Thing's nerve endings. And this particular nerve ending has just had his optical sensitivity enhanced.
Yes, this week I've sat on the hut's porch seeing very clearly how neatly all all around me the world is so pleasingly put together, both in a biological and a spiritual sense.
*****
Best wishes to all Newsletter readers,
Jim
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