April 26, 2018

MUSTARD GREENS IN THE YUCATAN
In our January 28th Newsletter I showed how my garden's dry-season production had been drastically increased by planting individual plants of certain crops far too close together, according to usual thinking. The crowded plants created a green blanket that sheltered the soil from wind and sunlight, thus keeping down the evaporation of water by being a "living mulch." Our Living Mulch page is at https://www.backyardnature.net/mexnat/lv-mulch.htm

One of the living-mulch crops featured there was a bed of mustard greens, shown at https://www.backyardnature.net/n/18/180128so.jpg

Nowadays, three months later and with the worst of the dry season's heat and dryness starting to bear down on us, my mustard greens still are producing much more than I can eat or give away. Despite the heat, the leaves aren't bitter. In fact, this is the best crop of mustard greens I've ever produced. Up north, my greens usually are attacked early on by tiny, black beetles that skeletonize the leaves. Here the native flora doesn't include members of the Mustard Family, so invertebrates didn't evolve to feed on that family, and I'm guessing that that's the reason for such success.

Some of my plants are beginning to flower. You can see one of them photographed on an afternoon when the temperature was right at 100°F (38°C) at https://www.backyardnature.net/n/18/180426br.jpg

In that picture you can see the leaves' frilly margins, distinguishing this cultivar from numerous other kinds of "leaf mustards." The seed package from which these plants grew, purchased at a small ACE Hardware a year ago during my visit with family in rural western Kentucky, lists our cultivar as Southern Giant Mustard.

Leaf mustards are developed from the species BRASSICA JUNCEA, and my old Bailey's Manual of Cultivated Plants recognizes these varieties of tht species: crispifolia, with cut, curled and crisped leaves (ours); foliosa, with large, wavy-margined leaves; longidens, with oblong leaves bearing narrow, forward-pointing lobes, and; multisecta, with leaves divided into threadlike lobes.

The genus Brassica is a big, very important one, embracing cabbage, kale, Brussels sprouts, cauliflower, rape or Canola, rutabaga, turnip, and the various edible-leaf mustards. It's a member of the Mustard Family, the Brassicaceae.

Our Southern Giant Mustards' flowers are classic Mustard Family blossoms, as seen at https://www.backyardnature.net/n/18/180426bs.jpg

Up north at this time sometimes you see big springtime fields breathtakingly yellow with blossoms of various Mustard Family species, every flower with four petals standing opposite one another. Also, typical of the family is that once the flowers are pollinated and the petals have have fallen off, semi-succulent ovaries start enlarge below the newer flowers to form little fruit pods, each on its own slender stem, or pedicel. Other features of the Mustard Family are seen closer up, at https://www.backyardnature.net/n/18/180426bt.jpg

Here we see best in the lowest flower what's probably the most distinctive feature of Mustard Family blossoms: Each flower bears six stamens, of which two are shorter than the other four. The genus Brassica can be distinguished from other of the Mustard Family's 300 or so genera by features seen at https://www.backyardnature.net/n/18/180426bu.jpg

Notice that these fruit pods are tipped with thick, broad-based "beaks." The beak can be thought of as a thickened style, though in some species it may contain seeds. A slight constriction separates the beak from the pod's main body below, where seeds are produced. The seed-bearing part of the pod consists of two sides, or "valves," separated from one another by a silvery partition. Spherical, brown seeds are released when the valves separate. When more of my plants are in fruit, I'll collect the seeds for the next planting.

And there'll certainly be a next planting, especially after reading about the advantages of eating mustard greens. Here's something I found on the Mustard Greens page of the AdamsHeirlooms.Com website:

"The cholesterol-lowering ability of steamed mustard greens is second only to steamed collard greens and steamed kale, in their ability to bind bile acids in the digestive tract."

Also, mustard greens contain two glucosinolates, sinigrin and gluconasturtiian, thought by some to offer protection against cancer. And they are an excellent source for vitamins K, A, C and E, as well as for manganese, calcium and dietary fiber. They're a very good source of potassium, vitamin E, vitamin B2 and magnesium, and a good source of vitamin B1 and vitamin B3 (niacin).

Mustard greens originated in the Himalayan region of India and have been grown for consumption for over 5000 years.

*****

YUCATAN JASMINE
On my Sunday biking trip to the frutería in Temozón a leafless, shoulder-high bush or small tree turned up at the forest's edge bearing a diffuse constellation of small, conspicuously white flowers, the likes of which I'd never seen. You can see the visual effect it made at https://www.backyardnature.net/n/18/180426sd.jpg

Up close, the flowers displayed the important diagnostic feature shown at https://www.backyardnature.net/n/18/180426se.jpg

The filaments of its ten stamens were joined at their margins, forming a cylinder around the female parts, or pistil. When the flower underside was looked at, another important feature turned up, shown at https://www.backyardnature.net/n/18/180426sf.jpg

Instead of a white corolla arising from a green calyx, as I expected to see, the green calyx's lobes, or sepals, expand and become white, with there being no apparent corolla.

Because of the stamens' united filaments, my first guess was that this pretty species belonged to the big Hibiscus Family, but when I checked every Hibiscus Family genus known to occur in the Yucatan, nothing turned up like it. In the end, I had to use Colby University's online Plant Family Identification Key, which led to the strictly tropical Flacourtia Family, the Flacourtiaceae, and the further fact that nowadays the Flacourtia Family has been sunk into, of all things, the Willow Family, the Salicaceae.

With that insight it was easy to determine that our demure little tree or shrub was SAMYDA YUCATANENSIS, a species endemic only to the Yucatan Peninsula. It's not known well enough to have an English name, but in Spanish it's known as Jazmín Yucateco, which translates to Yucatan Jasmine. Unrelated to the real Jasmine, it's called that simply because its flowers are white and fragrant like Jasmine blossoms.

The Maya certainly know about this species, for three Maya names are registered for it. Probably its main fame with the Maya rests on its flowers being good sources of nectar for bees, plus they flower at a time of year when relatively few species are blossoming.

A 2014 paper entitled "Samyda yucatanensis: el jazmín yucateco" by Luz M. Calvo Irabién, and issued by CICY in Mérida, tells us of the presence in the flowers of an essential oil called farnesol. Farnesol is much used in the perfume industry to intensify sweet odors, plus to some insects it's a pheromone, or sexual hormone.

*****

TEXAS PERSIMMON'S HANDSOME TRUNKS
At https://www.backyardnature.net/n/w/tex-pers.htm we've admired the Texas Persimmon's flowers and fruits, but it wasn't until I camped beneath one, this April 2nd in Amistad National Recreation Area just outside Del Rio, Texas on the border with Mexico, that I realized just how pretty the tree's trunks could be. Earlier I'd only known younger trees or stunted ones on dry limestone cliffs. You can see the smooth, dark gray trunks of this mature tree beneath which I pitched my tent at https://www.backyardnature.net/n/18/180426pr.jpg

I'd not even realized it was a Texas Persimmon until my attention was drawn to a flower whose white corolla was about to fall off, after drying up and turning brown, as shown at https://www.backyardnature.net/n/18/180426ps.jpg

*****

FOSSILS IN THE DEL RIO CLAY
Toward the end of the hike from Amistad's Visitor Information Center and Spur 454, the trail climbs briefly onto a low, sparsely vegetated cliff. Layers of bedrock are exposed here, with numerous broken-off, flat pieces of rock strewed across the ground. From the smoothly eroded surfaces of these flat rocks, white fossils emerge in abundance, as on the laptop-computer-size piece shown at https://www.backyardnature.net/n/18/180426fp.jpg

A close-up of the snail-like fossils is seen at https://www.backyardnature.net/n/18/180426fq.jpg

Amid these fossiliferous rocks stands a wonderful National Park Service information marker telling us that the surrounding layers of outcropping rock are known as the Del Rio Clay. This clay and its fossils were deposited during the Cretaceous Period, about 100,000,000 years ago. The marker even bears a drawing of a spiraling, snail-like fossil shell looking like those in the above pictures, identifying them as members of the extinct genus Ilmatogyra, formerly classified as Exogyra. The USGS page describing the Del Rio Clay lists Exogyra arietina as an abundant megafossil in the unit, so a good guess is that that's the species in our rocks, possibly now shifted to the genus Ilmatogyra.

A picture of the marker's drawing of this fossil, and text accompanying it, is at https://www.backyardnature.net/n/18/180426fo.jpg

Despite the fossils' snail-like looks, they're not snails or even closely related to snails. They are indeed mollusks, like snails, but the Mollusk Phylum is divided into three main subdivisions, or classes: bivalves such as clams and oysters; cephalopods like the octopus, and; gastropods like snails and slugs. Our marine Cretaceous fossils are bivalves along with clams and oysters.

In fact, our fossils belong to the Oyster Order, the Ostreoida, and within that, the Gryphaeidae Family, often known as the foam or honeycomb oysters. Since oysters are bivalves, they have two shells, not one as with snails. Looking at our pictures, I see nothing that might be the second shell. However, the marker's drawing of a Del Rio Clay fossil shell shows a kind of thumbnail-like appendage at the top, left, so maybe that's the second shell. I read that species in the Gryphaeidae are "inequivalve" -- the two shells being unlike one another. The left, lower shell is convex, while the other is flat or slightly concave.

The Cretaceous Period during which this bivalve lived came to an abrupt end when about 65,000,000 years ago a six-mile-wide object (10 km) struck the ocean where the Yucatan Peninsula now exists, killing off the dinosaurs, and nearly half of all marine genera. Is that what caused our Del Rio Clay oysters to go extinct?

Isn't it something to think of a kind of living thing that once was as abundant as our fossil species obviously was, so suddenly simply disappearing from the face of the Earth -- a whole kind of being obliterated and leaving no descendants? Might not the same happen to us humans?

*****

HAPPINESS WITH & WITHOUT MENTALITY
The philosopher Baruch or Benedict Spinoza (1632-1677), for whom "God" and "Nature" were two words for the same thing, had a great deal to say about happiness. In his usual way, before he set about proving his thesis, he defined his terms.

To begin with, most of us might agree that a happy life is one filled with joy and love. Spinoza defines "joy" like this:

That definition should be considered in the context of Spinoza's belief that the only "perfection" is God/Nature. Therefore, "joy" manifests when one draws closer to God/Nature. Spinoza builds on his definition:

In this light, when we "fall in love" with something or someone (external causes), something in the beloved promises for us the possibility of experiencing greater "perfection" in our lives, that perfection being Godliness/Naturalness. Note that Spinoza doesn't include carnal attraction in his definition for love. Having a handle on "love," now we can make sense of Spinoza's concept of happiness:

And the only "object eternal and infinite," as Spinoza keeps saying, is God/Nature.

Probably most people recoil from such an intellectual approach to defining happiness. I think of the matter as I do with fossils.

I mean, it's definitely a fine thing to find a child's pleasure in simply looking at a fossil's elegantly coiling shell, its color, texture, and experiencing how it feels in the hand. However, match that satisfaction with how we feel upon realizing that the shell we're looking at is what's left of a living creature that moved along the muddy floor of a warm, shallow sea about 100,000,000 years ago, back when North America, Europe and Asia all formed a single continent, and dinosaurs were the dominant terrestrial life form. Think how long a year is, and then try to visualize that fossil having survived 100,000,000 of them...

This second state of appreciation is gained only through one's mentality. However, it shouldn't be overlooked that to Spinoza, everything -- including carnal attraction -- is part of God/Nature, so that's also included in his concept of perfection, just that it's not mentioned in his formal definition.

So, consider the difference between the satisfaction of merely registering a shell's physical qualities, and the profound insights that mentality can bestow regarding that's shell's history and the associated implications. That difference points to the difference between happiness based on animal senses, and Spinoza's mental-based happiness arising from drawing ever closer to God/Nature, and harmonizing ourselves with that perfection.

Now, what good does it do to think like this, and why are these words written here? It's because the above thought patterns support what's been said in this Newsletter again and again over the years.

Spinoza's "passage from a less to a greater perfection" is what I've more clumsily referred to as the process of Nature conveying to us paradigms with which we can harmonize our behaviors, to become "happier" and progress toward a higher spiritual level.

*****

Best wishes to all Newsletter readers,

Jim

All previous Newsletters are archived at https://www.backyardnature.net/n/.