September 22, 2018
BEACH PEANUT
Last week I spent a couple of days camping on the coast between Río Lagartos and Las Coloradas on the Yucatan's north-central coast. In white, shell-based sand where the beach met the dunes, a prettily flowering, sprawling herb turned up that somehow I missed during my year of residency in Río Lagartos. You can see it at https://www.backyardnature.net/n/18/180922ok.jpg
When the flower was examined from the side I was surprised to see long, sticky, gland-tipped hairs covering the corolla tube, shown at https://www.backyardnature.net/n/18/180922ol.jpg
Removing one side of the flower made things a little clearer, as seen at https://www.backyardnature.net/n/18/180922om.jpg
The interesting point is that the magenta thing isn't a corolla. It's a calyx expanded to look like a corolla, and there is no corolla. The flower also has a leafy bract -- a modified leaf -- at its base. The corolla-like, trumpet-shaped calyx, the leafy bract at the flower's base, the numerous stamens and the magenta color all suggested that the plant was a member of the Four-O'Clock Family, the Nyctaginaceae. Knowing that, it was easy to match pictures with the few members of that family present in the Yucatan.
Since our beach plant also occurs on beaches in southern Florida, it goes by several English names, including Beach Peanut, Dune-groundnut and Burrowing Four-O'Clock. It's OKENIA HYPOGAEA. The English names speaking of peanuts, groundnuts and burrowing indicate an interesting feature of the plant. The online Flora of North America page for the species says that the species' reproductive biology needs to be studied, but that on plants with conspicuous flowers, like ours, the flowers may be unisexual male. Fruits develop from small, closed, self-fertilizing flowers -- cleistogamous flowers -- whose flowering stems, or peduncles, curve downward, possibly entering the sand, where the fruit develops at the peduncle's tip.
This is similar to how the unrelated Peanut plant does things. Fruits developing below the ground like this are said to be geocarpic. I didn't know about Beach Peanut's burrowing peduncles and geocarpic fruits until I read this, so at the beach I didn't know to look for them. However, once I knew, I went back to the first picture showing stems and leaves and, behold, there we see two stiff-looking items projecting from the stem looking like burrowing peduncles, as you can see yourself. I wish I'd known about this and I'd have dug to see if the plant had "peanuts."
Beach Peanut occurs from Florida and Mexico south to Nicaragua. In Florida it's on the state's Endangered Species list, because of its small distribution area and the fact that Florida beaches are much disturbed by development, dune buggies and the like. In Mexico it's not considered to be threatened.
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TULIPÁN AT THE BEACH
At https://www.backyardnature.net/yucatan/tulipan.htm we look at the Tulipán, or Turk's Turban shrub, a native species that's very common throughout the Yucatan and much appreciated for its pretty, hibiscus-like flowers. Last week during my camping trip to the Yucatan's northern coast, amid scrubby vegetation much stunted by salt-spray, the lack of water in sandy soil, extreme heat and glaring sunlight, next to my tent atop a dune grew a waist-high bush with obvious Tulipán flowers. However, the leaves were so small and leathery, and the flowers looked a little different from what I remembered, that I thought I might have a second Tulipán species -- a second species of the genus Malvaviscus. You can see the plant's flower and leaves at https://www.backyardnature.net/n/18/180922ma.jpg
Thing is, no second Malvaviscus species is listed for the Yucatan. Apparently the coastal dunes' extreme environmental conditions caused the leaves to look so different. Also, the feature of the flower that caught my attention was that its base was enclosed within a cage-like involucre of narrow bracts. I remembered the flowers having a cuplike calyx with short, wide lobes. However, later I remembered that even flowers on inland plants are subtended by narrow bracts, just that usually they're not held so close to the calyx as in the picture.
Still, it's worth posting our picture just to show another face of this pretty plant, and to acknowledge that this is a tough, adaptable species table to thrive in habitats ranging from humid, shady woods to atop those wind-swept, salty sand dunes.
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PLENTY OF QUEEN-OF-THE-NIGHT CACTUS
At https://www.backyardnature.net/q/rat-tail.htm we look the arboreal, wandering cactus Selenicereus grandiflora, sometimes called Queen-of-the-night. I've always wondered whether the one found on a tree trunk just outside the rancho's gate was natural or placed there years ago. Last week during my camping trip to Yucatan's northern coast, sprawling atop the salt-spray-stunted scrub right behind the dunes a few meters inland from the beach, I found plenty of the species, clearly growing wild there. You can see a typical part of a long, much-branched stem wandering atop a clutter of died-back shrubs at https://www.backyardnature.net/n/18/180922sq.jpg
These stems were much more robust, and purplish instead of green like the ones profiled earlier growing in shade, as seen at https://www.backyardnature.net/n/18/180922sp.jpg
Plants exposed all day long to intense sunlight often develop reddish or purplish color, the pigments serving as a sunscreen. Despite those differences in appearance, the spines were just like those at the rancho, as seen at https://www.backyardnature.net/n/18/180922so.jpg
Whenever the stems dipped low, often they issued stout adventitious roots, which may have collected moisture during the heavy dews that drenched my tent each morning, and probably from fogs that sometimes roll in off the water. These are shown at https://www.backyardnature.net/n/18/180922sn.jpg
In a previous Newsletter I wrote, "Taxonomy of the genus Selenicereus is notoriously confused and understudied, so the species name grandiflora has to be seen as a placeholder until the group is better understood." That's still the case with this new find.
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GRASSLEAF SPURGE
Beside the rancho's entrance gate, shaded by the big Purple Allamanda bush, there grows a weedy spurge, spurges being members of the huge genus Euphorbia (more than 2000 species recognized, with 32 species listed for the Yucatan Peninsula) in the appropriately even bigger Spurge or Poinsettia Family, the Euphorbiaceae. Euphorbia species are easy to recognize because they all bear flowers in a unique kind of flowering structure, but because of the large number of species, figuring out which Euphorbia you have is often hard.
At the excellent Malezas de México website (Weeds of Mexico), which provides pictures of Mexican weeds, I tried to match our rancho weed with one of the 15 Euphorbia species listed there. Actually, I only checked 14 species, because one of them was named Euphorbia graminea, and the graminea part in that name indicates that the plant is "grasslike." And nothing about our gate species suggested a grass, as you can see at https://www.backyardnature.net/n/18/180922eu.jpg
A closeup showing the weird flowering structure is shown at https://www.backyardnature.net/n/18/180922ev.jpg
In that picture, the object looking like a green tomato occupying the image's lower half is an ovary, the future capsular-type fruit. It hangs on a curved, white stem, or pedicel, issuing from a green, cuplike structure, the involucre. Also arising from inside the involucre are stamens. Euphorbia flowers are unisexual, the ovary being what's seen of the female flower, and the stamens being what's seen of the male flowers. And each male flower produces only one stamen. In other words, inside the involucre there are several male flowers, and the single female flower, with her ovary hanging outside the flowering structure. The flowering structure is called a cyathium, and when you see it, you have a Euphorbia.
Identifying this species took more time than usual because it turned out that our gate Euphorbia was indeed EUPHORBIA GRAMINEA, the one species on the Mexican Weeds page I hadn't looked at because it didn't look like a grass. It turns out that this is a very variable species. If it's growing in a dry place with abundant sunlight its leaves are slender (from 3mm or 1/10th inch wide), but if it's in the shade during the rainy season, like ours, it looks like what our images show. In English Euphorbia graminea is known as the Grassleaf Spurge, and is distributed across the US southern tier of states south through Mexico and Central America and much of South America, plus it'ss an invasive weed in the Caribbean, Asia, and the Pacific Islands.
In recent years an ornamental cultivar has been produced of Euphorbia graminea, marketed under the trade name "Diamond Frost." On the FloriData.Com webpage for the species, I read that "Diamond Frost" is prized for the abundant and long lasting large white bracts of its cyathia , and that it never stops blooming. It's described as the most common variety of grassleaf spurge in commerce today. It grows into mounds up to 5ft (1.5m) across.
In Mexico it's used as a forage plant, and the plants when young can be eaten by humans.
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ARMY ANTS, ELEPHANT EARS, & PHI
Biking down the narrow trail from the hut to the tool shed, on my way to Ek Balam, my shoulder brushed against a seven-ft-tall (2m) Elephant Ears plant, and immediately began burning with pinprick ant bites. The Elephant Ears had been crawling with foraging army ants, and when I stopped the bike to brush them off, there I was standing in the middle of the advancing wave of them, biting ants ascending my hairy legs like diffuse ink stains. Especially before big rains you can run into army ants several times a day. You just can't predict where they'll be, and if you move around at all you're bound to cross paths with them.
De-anted, I continued my ride to town, thinking about ants and other colonial invertebrates. Despite their biting me, I'd felt bad about stepping on them when I escaped. I don't like killing anything if I can avoid it, not even weeds, but Life on Earth is designed so that all things that move around and eat must take the lives of other beings.
Maybe to make myself feel better, I remembered the idea being expressed by some that it's more appropriate to think of the entire colony of a colonial species -- such as ants, termites, wasps, honeybees and such -- as the actual "being," while the individual ant or bee out doing her job for the nest is more like a red blood cell in a body's circulatory system, than what we think of as an independent being. Why must a living thing's circulatory agent flow through veins and absorb nutrients through membranes instead of moving about on legs and feeding itself with a mouth? And why must awareness be limited to animals with nervous systems like ours? Octopuses display enough intelligence that some restaurants have stopped serving them as dishes, though all cephalopods have nervous systems radically different from us vertebrates. Thinking like this, maybe I'd only slightly weakened the actual army ant "being" by taking some of its roving circulatory agents out of circulation.
Actually, a lot of people are asking similar questions, especially in the form of "What is consciousness and where is it centered?" and the same for intelligence. The issues involved are enormous, and the answers, or even hints of answers, would not only usher in a new age of computer science and robotics, but also put a lot of humans out of their brain-using jobs, and change our concepts of what we humans are. If some of our top scientists are right, there's really no reason why eventually we won't construct something much smarter, more aware, more artistic and creative than any human.
My friend Eric in Mérida sends me links to articles with titles like "Consciousness: The Mind Messing With the Mind," "The AI Revolution: The Road to Superintelligence," "The Case for Panpsychism,"and "Artificial intelligence: ‘We’re like children playing with a bomb’." That last essay is subtitled, "Sentient machines are a greater threat to humanity than climate change, according to Oxford philosopher Nick Bostrom." Probably you can Google these titles and read them, or if they've been removed, the key words in the titles will summon thousands of similar works.
Nowadays mostly scientists and philosophers are trying to organize their thoughts about these issues, because with consciousness and general intelligence it's hard to conduct the usual kind of experiments. For example, neuroscientist Giulio Tononi, whose integrated information theory is a major force in the science of consciousness, has invented a unit, called phi, Φ, for measuring how conscious an entity is. The word "entity" is used because the assumption is that other animals besides humans, as well as plants -- maybe even devices as simple as thermostats -- may have at least glimmers of consciousness, a subjective self.
As for my army ants. I see no reason for ant awareness -- the ant "soul" -- to be centered either in the whole colony, or the individual ant. It can be diffuse, so that as I ran my way out of the ant wave I was intelligence/awareness running through intelligence/awareness... intelligence and awareness like curds in cottage cheese, each curd more or less expressing its own identity and presence, but still only a diffuse lump in the whole carton of cottage cheese...
And, it needn't stop there. I "feel in my bones" that the Earth and all its interacting living and non-living things -- Gaia -- has Her phi, and our Galaxy, and the whole Universe with all its dimensions may turn out to be nothing but Dr. Tononi's phi in its pure, complete state. In fact, maybe I'm actually talking about the "One Thing" often mentioned here, maybe that exactly.
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Best wishes to all Newsletter readers,
Jim
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