May 24, 2018
MEXICAN EBONY FRUITING
Three Sundays ago as I biked toward the frutería in Temozón, just three or so kilometers north of town, I was astounded to see two large trees along the road very conspicuously bearing large crops of golden-yellow fruits. You can see part of a branch of one tree at https://www.backyardnature.net/n/18/180524sw.jpg
I was astonished because, traveling this same route almost every Sunday for a year and a half, how could I have missed those trees until now? Why hadn't I noticed the fruits the previous week, or this time one year ago? I'd never seen anything like this. The trees, entangled among many other trees, bushes and vines, were hard to get to, and the fruits were rather high up, so the best fruit picture my camera's modest telephoto lens could provide is shown at https://www.backyardnature.net/n/18/180524sx.jpg
The leaves arise alternately on the stems, and are pinnately compound, almost like those of the north's walnut trees. The fruits are unusual not only for their abundance, but also each fruit bears a kind of nipple at its end, and at its base narrows into a kind of stem. Most of this tree's fruit bodies are ±spherical, but some fruits display two bulging parts, looking like peanut shells.
My Maya friend at the frutería in Temozón looked at the above pictures on my camera's display screen and said he'd seen this tree before. It's not planted but rather grows in the wild, where it's uncommon and not much good for anything other than that birds eat its fruits.
My delay in introducing you to this tree is because it took several sessions on the Internet during my visits to Ek Balam to identify it. At first even its plant family was unclear. But then in the above photo I noticed that the fruit pods show sutures along their sides, where at maturity they split open to release their seeds. My friend said the seeds were beanlike, and in the Bean Family many species bear pinnately compound leaves like these, so I began looking in the Bean Family, which is so huge that it took a while.
The tree is indeed in the Bean Family. It's SWARTZIA CUBENSIS, in English known as Mexican Ebony, Mexican Royal Ebony, and by an indigenous name of Katalox. It's native to southern Mexico, Central America and northern South America. Judging from the literature, it's uncommon or rare, or even very rare, in this area. In rainier climes the tree can reach 100-130ft tall (30-40m) but ours, though rising above trees around them, grew less than half that tall.
Despite my friend's claim that just birds like it, one reason Mexican Ebony may be rare here is that it's internationally famous for its hard, strong, blackish wood. True Ebony trees, members of the Ebony or Persimmon Family, are being overharvested everywhere and are disappearing fast because of their high market value. Mexican Ebony is gaining fame as a substitute for true Ebony, and now it's growing rare, too. On the Internet, searching on the keywords of "Katalox Mexican Ebony" you can find many companies selling its timber, and marketing products made from the wood. During my brief survey I found a company constructing guitars from the wood, and another selling handmade kitchen utensils -- very dark, expensive wooden spoons, spatulas, butter-smearing knives, etc.
I'm watching these trees and hope next to see the legumes offering their beans to the birds.
*****
FAIRY HIBISCUS FLOWERING
In very thin, dry soil atop a dislodged limestone boulder along the road to Temozón, a bright splash of rose-red color caught my eye. You can see what it was at https://www.backyardnature.net/n/18/180524hb.jpg
With such flowers and leaves it could hardly be anything other than a member of the big Hibiscus Family. Up close, a beautiful blossom confirms this with its numerous stamens' slender filaments joined at their bases to form a cylinder -- the "staminal column" -- surrounding the long style, as shown at https://www.backyardnature.net/n/18/180524hh.jpg
The flower's single pistil with its stigma-tipped style branches spreading away from one another above the cluster of yellow-orange anthers, its five-toothed calyx, and the collar of several bracts below the calyx, all point to the genus Hibiscus.
Though many Hibiscus species are favorite ornamentals, and this one would be an attraction in any garden, in our area it's considered a weed. It's HIBISCUS POEPPIGII, in English sometimes known as the Poeppig's Rosemallow or Fairy Hibiscus. It's native from southern Florida through Mexico into Guatemala, as well as Cuba and Jamaica. Here it flowers and fruits more or less throughout the year, whenever there's enough rain. With enough water it can reach seven feet tall (2m) but ours was only about one foot tall.
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COW'S-HOOF FRUITS
At https://www.backyardnature.net/yucatan/bauhinia.htm we admire a small, Bean Family tree very common in this area, especially disturbed places, the white-flowered Cow's Hoof. On that page you can see its cow-foot-shaped leaves, and orchid-like flowers. Nowadays the tree's legume-type fruits are to be found, as shown at https://www.backyardnature.net/n/18/180524bh.jpg
These legumes are unusual because their few beans are restricted to the fruit's lower half, giving the fruit something of a meat-cleaver shape.
*****
WILD TAMARIND SEEDLINGS
Last week I described the abundant and ubiquitous Wild Tamarind's pioneer status in the ecological process of forest succession in the Yucatan. Here at the rainy season's beginning, Wild Tamarind seedlings are popping up everywhere, including in the garden. Since Wild Tamarind seedlings are so important ecologically, it's worth paying attention to them. You can see one with its two photosynthesizing cotyledons, between which the seedling's first regular leaves are emerging, looking like a green feather, at https://www.backyardnature.net/n/18/180524lv.jpg
Many seed types are germinating, but it's easy to distinguish the Wild Tamarind's by their fairly large size/ tongue shape, yellowish-green color, and by the backward-projecting, sharp-tipped ears, or auricles, on each side of each cotyledon's base.
In a couple of days, the seedling's true leaves expand to the point that they begin looking like real compound leaves, as you can see on the left in the picture at https://www.backyardnature.net/n/18/180524lu.jpg
Interestingly, those first two leaves are only once pinnately compound, like locust leaves. However, Wild Tamarind's mature leaves are twice compound, like acacia leaves. In the above picture, the seedling at the right has developed more typical twice-compound leaves
When these two seedlings were uprooted for the photograph, a familiar odor wafted around me, apparently issuing from the injured roots. The odor perfectly matched the bitter-garlic taste of the Wild Tamarind's half-mature edible beans.
Recently I was studying aphids on various plants and noted that the tiny sap-sucking insects infested numerous species, but not Wild Tamarinds, even when they grew entangled among infested plants. Now I'm wondering if this strong taste in the beans, and the odor of the injured roots, arises from a chemical compound that might be tasty to a hungry human, but toxic to a sap-sucking insect.
*****
SPURGECREEPER MALE PARTS
At https://www.backyardnature.net/mexnat/dalecham.htm we look at a weedy vine commonly seen here twining up bushes and trunks of small trees at woods edges, the Spurgecreeper. On our Spurgecreeper page we see that the vines' tiny flowers are subtended by two sets of conspicuous green bracts. The bottom set of broad bracts encloses several flower clusters, and then each cluster arises from a second set of bracts, displaying slender, very hairy lobs. This very unusual double-bract situation is clearly seen in the photo at https://www.backyardnature.net/n/16/160710df.jpg
In that picture the light green, spherical items are parts of the ovary, so we're looking at a maturing cluster of unisexual female flowers. Ever since that picture was taken two years ago I've been looking for male flowers, and not until this week did I find them. The breakthrough came when I was looking at the flower cluster shown at https://www.backyardnature.net/n/18/180524dc.jpg
Most of the left side of that picture is occupied by the broad, leafy lower bracts subtending the whole cluster. So, what are the spherical items in the picture's lower, right corner, and what are those three curved, slender items to the right of the buds? These mysteries sent me looking into other clusters, where I found what's shown at https://www.backyardnature.net/n/18/180524dd.jpg
So, the spherical items had been unopened buds of male flowers. In the above photo, two buds have opened, revealing stout stalks composed of fused stamen filaments, and atop the filaments rest bundles of pollen-producing anthers. The green, slender, curving items at the picture's right are the female flowers' styles, topped by knobby stigmas. The styles' bases disappear below into a hairy zone in which the ovaries are hidden. Later the the ovaries will enlarge into fruits, in the center of which will arise the styles, as we saw two years ago.
Fortunately I had help interpreting these flower parts from the a illustrated 1972 article by Grady and Barbara Webster in the American Journal of Botany, entitled "The Morphology and Relationships of Dalechampia scandens (Euphorbiaeae)," which is freely available in PDF format. Just search on the title.
Of course all this is rather obscure botany, but when you treasure knowing various ways Nature has figured out how to do things, these often-hidden details are a pleasure to behold. Also, now I have a much more congenial relationship with our local Spurgecreepers, and look forward to finding someone who will ooh and ah when in real life they see what's on display here.
*****
SPINIEST OF CACTI
During my recent camping trip in the highlands east of Saltillo, Coahuila in northeastern Mexico, on April 5th I started out hiking on a valley floor, and climbed a small limestone mountain that was grassy and scrubby at its base, but forested on top. Toward the top, at ±7000 feet in elevation (2100m), where trees were just starting to appear, I found commonly growing what must be the spiniest of all cacti. If it were any spinier surely not enough sunlight could penetrate the spines for photosynthesis to take place. You can see one of these amazing plants at https://www.backyardnature.net/n/18/180524co.jpg
A close-up look of some spine clusters is seen at https://www.backyardnature.net/n/18/180524cq.jpg
If you could see the cactus's green body, it would consist of cylindrical stems about as thick as wieners spreading from a common. Most stems only grew tall enough to stab their spines into your calf if you backed into one. I've done that, and can report that there's something else special about the spines, beyond their abundance. And that is that if a spine sticks you, a hollow sheath that was enveloping the spine come off, and stays stuck in your skin even when the spine withdraws. A hollow spine-sheath is shown at https://www.backyardnature.net/n/18/180524cp.jpg
Scraping your thumbnail across the sheath's surface, you can feel that it's a little rough, and when you pull the sheath out of your skin you quickly realize that the roughness is caused by backward-pointing projections that tear as your flesh as the sheath is being pulled out.
Despite the cactus producing no flowers at this season, I could see that no other such super-spiny cactus of this shape, size and form existed in the region, using the excellent, well illustrated, Spanish-language Guía de Cactáceas del Estado de Coahuila by Alfredo Flores, freely available on the Internet in PDF form at http://www.sema.gob.mx/descargas/manuales/cactus.pdf
It's CYLINDROPUNTIA TUNICATA, in the online Flora of North America referred to as the Sheathed Cholla. Its presence in the Flora is due to the species occurring in the limited part of southwestern Texas occupied by the Chihuahuan Desert, from 1500 to 2300m in elevation (4900-7550ft). From Texas the species continues on south and west throughout the Chihuahuan Desert of northern Mexico, plus it 's invasive in numerous other countries, apparently introduced by humans and livestock shipments.
The Flora of North America makes the interesting point that the Sheathed Cholla's fruits usually are sterile. Still, in much of norther Mexico the species is abundant, despite large parts of its population being wiped out by ranching and urban sprawl. Apparently it spreads mostly vegetatively, its broken-off joints rooting and forming new plants.
Sometimes Sheathed Cholla is planted to form impenetrable hedges around plantations. In Hawaii where the plant has been introduced, Hawaiians have been documented using juice from the cactus's stems and roots for constipation. Up north in cactus gardens, Sheathed Cholla often is regarded as desirable because during those seasons when no cactus is flowering or fruiting, this species at least catches the eye with its remarkable spines.
*****
BEGONIAS & BASIL SEEDLINGS IN SUNLIGHT
Maybe sometime in your life you've had a potted begonia perched on your kitchen windowsill and maybe one winter morning as sunlight streamed through the window you saw how the begonia's succulent flesh glowed, seeming to emit more light than possibly it could been gathering into itself. And maybe you stood and stared at the begonia feeling a special kind of tranquility and sense of rootedness that for the rest of the day glowed inside like the sunlight had in the begonia.
My life has been graced with many such moments, and here in my present tropical heat and humidity I've been remembering them, for I have basil seedlings emerging in a tray, and in the sunlight they glow with the same thoughtful music as my begonias once did. Seeing them sets me adrift in lengthy old-man reveries.
For example, maybe precise sequence of the DNA base-pairs that code for photosynthesis -- which first arose in our ancestors the oceanic plankton at the dawn of aerobic photosynthesis 2.4 billion years ago -- composes some kind of deep-seated universal melody that profoundly resonates with its sister melodies, or harmonics or echos or ghosts among our human heartstrings.
And yet, the whole thing is mechanical. The Sun's energy all aglow here on Earth emits from nuclear fusion, a process that, once ignited in the Sun's core, pursues its agenda like clockwork to the end, all in accordance with E=MC2. And in Earth's plants all chemical doings required for photosynthesis are spelled out, step by step as in a lab manual, in the cells' DNA.
And that DNA issues other orders, too, for example commands and procedures for reproduction, and not only the reproduction of our exact selves, but beings a little different, in short, to reproduce in a way that over time things evolve, evolve toward more and more that's smarter and smarter, and ever more sensitive and alert, everything ever more beyond what it already is.
And so, what I experience before a sunlight-charmed begonia or basil seedling does seem to go a tiny bit beyond pure mechanism. By engendering these thoughts, feelings and yearnings, it's as if I'm being drawn into some kind of realm aglow with pure presence-of-the-moment, like the flesh of a remembered begonia, or a basil seedling, bathed in radiance right now.
*****
Best wishes to all Newsletter readers,
Jim
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