JIM CONRAD'S
NATURALIST NEWSLETTER
Issued from Rancho Regenesis
in the woods near Ek Balam Ruins north of Valladolid in
Yucatán, MÉXICO

August 27, 2017

MALE BAMBOO
Not far from the hut there's a sinkhole, or cenote as they're called here, in which numerous plantings have been made. A foot trail spirals to the sinkhole's bottom, and the owner visualizes someday visitors following that trail as they admire the plantings. One of the most impressive species there is a kind of giant bamboo growing maybe 50ft tall (15m). Vegetation inside the sinkhole is so lush that there's no perspective from which the bamboo clump can be seen in its entirety, but you can begin getting an idea of what the bamboo is like at http://www.backyardnature.net/n/17/170827bd.jpg

The bamboos' stems, or "culms," are about four inches in diameter (10cm). My hand on a culm for scale is shown at http://www.backyardnature.net/n/17/170827bc.jpg

The big culms are used in various ways at the rancho, so occasionally they've been cut. When cut between the culms' joint-like nodes, they're hollow, as you can see at http://www.backyardnature.net/n/17/170827bb.jpg

New culms sprout from the soil as shown at http://www.backyardnature.net/n/17/170827bf.jpg

In that picture notice that the culms' lower nodes are sprouting adventitious roots. Standing at the bamboo cluster's base you can look up and see grass-like leaves -- bamboos are members of the Grass Family, the Poaceae -- on forking, slender branches, as seen at http://www.backyardnature.net/n/17/170827be.jpg

With all these impressive features, it seems that it would be easy to identify this giant grass. However, several bamboo species grow to great size, and some are very similar to ours, such as one usually called Giant Bamboo, Dendrocalamus giganteus, which grows even taller than ours. Normally I need flowers or maybe fruits to identify flowering plants, but ours have no flowers.

Still, by comparing our pictures with those on the Internet, and confirming measurements of section length, culm diameter, general culm color, appearance of the sprouts and other features, I've become fairly certain that we have DENDROCALAMUS STRICTUS, distributed widely across South and Southeast Asia, and planted in the tropics in many lands.

One reason I'm comfortable with the identification is that Dendrocalamus strictus is one of the most frequently cultivated giant bamboos, and is known to have been planted here in the Yucatan. In fact, one website advertises "bamboo lump charcoal" made from Dendrocalamus strictus growing at an hacienda here. That's at http://www.yucabam.com/where

At the www.guaduabamboo.com website I read that the stems of Dendrocalamus strictus grow and spread for 25-45 years, then sporadic flowering commences and continues for about five years. Elsewhere I read that once the culms have flowered, they die.

Dendrocalamus strictus goes by several English names, none of which are appropriate. On the Internet "Male Bamboo" seems to be the most commonly used, though the flowers are mostly bisexual -- so the plants are just as female as they are male. Sometimes its called "Solid Bamboo," but you can see that our culms are hollow inside. I read that in dry climates they may be solid or largely so, but in more humid environments they're hollow. They're also called Calcutta Bamboo, but the species is grown far beyond Calcutta, plus sometimes they're Guadua Bamboo, which doesn't ring any kind of bell here.

Besides the fact that Dendrocalamus strictus is so impressive, the reason it's grown so extensively is that it's very useful. In countries such as India where it's extensively grown, paper mills use it as a raw material, and also made from it are house frames, scaffolding, fences, furniture, musical instruments, mats, rafts, baskets, household utensils and much more. Planted on heavily eroded land, its dense network of roots holds the soil in place. The young shoots are edible and its leaves are fed to livestock. A "tea" brewed of the leaves and culm nodes is used in traditional medicine.

*****

EXOSTEMA FLOWERING
This week a disorganized system of stormy weather passed over us cooling things off, leaving the ground soggy, and kicking up some wind. Eventually that system became Hurricane Harvey, currently menacing the Texas coast. The light breezes we experienced caused trees and vines to fall onto the little trail through the woods to the rancho, so I went out with saw and ax and cleared the way. One of the fallen branches on the trail bore large, glossy, opposite leaves like those of a Coffee bush, and a snowball-like cluster of fair-sized, white flowers in a terminal panicle, shown at http://www.backyardnature.net/n/17/170827ex.jpg

The blossoms had some character, as shown at http://www.backyardnature.net/n/17/170827ey.jpg

First, notice that the slender style pointing toward the image's top, right thickens and grows green toward the knobby stigma at its tip. The corolla's lobes are unusually long and strongly curved back, and notice at the flower's very bottom how the green calyx bulges below the sepals. That indicates an inferior ovary -- an overy with the corolla and stamens arising at its top instead of at its base.

Opposite leaves looking like those on a Coffee bush and flowers with inferior ovaries... In the American tropics this combination of features usually but not always announces a member of the big Coffee or Madder Family, the Rubiaceae. To confirm the matter, look for conspicuous stipules connecting the tops of the opposite leaves' petioles; the branch had them. A stipule very typical of the Rubiaceae, brown and ready to fall off leaving just a stipular scar, is shown at http://www.backyardnature.net/n/17/170827ez.jpg

Realizing that we had a "Rube," I remembered having seen flowers very similar to those in our pictures on a bush or small tree on the Yucatan's northern coast, near Río Lagartos. That had been Exostema caribaeum, whose page is at http://www.backyardnature.net/yucatan/exostema.htm

So, here we'd found a second Yucatan species in the genus Exostema. It's EXOSTEMA MEXICANUM, distributed from central Mexico into Central America. Despite its handsomeness, it seems to be an obscure species with little information on the Internet about it.

Certainly I'd not have noticed it if the wind hadn't left a broken-off branch lying on the trail, even though twenty feet up, branches exposed to sunlight were generously flowering and buzzing with pollinators, a situation hinted out in the photo at http://www.backyardnature.net/n/17/170827ew.jpg

*****

BALSAM PEAR/ BITTER MELON FRUITING
At http://www.backyardnature.net/mexnat/balsam-p.htm we look at Balsam Pear fruits -- sometimes called Bitter Melon or Bitter Gourd -- which our Temozón neighbor Don Solís brought us, to feed the livestock. He'd produced a crop that he'd harvested and sold, and we got his remainders that were too old and bitter to sell.

On our Balsam Pear page you can see that the brightly yellow-orange fruits contain scarlet, slimy, beanlike seeds. Seeds I planted fresh from the fruits germinated easily and produced vigorous seedlings. I planted several along a fence, and now the vines, overgrowing the fence and completely hiding it, are producing numerous fruits, one of which you can see at http://www.backyardnature.net/n/17/170827bp.jpg

The flower in the picture is a male one. A close-up of a male flower with one side removed shows healthy looking stamens with orangish, pollen-producing anthers at http://www.backyardnature.net/n/17/170827bq.jpg

Members of the Cucumber/Melon/Gourd/Pumpkin Family, the Cucurbitaceae, to which Balsam Pear belongs, bear flowers with inferior ovaries, so the ovary would appear below the stamens and yellow corolla. In the above picture there's nothing beneath the corolla but a slender stem, the pedicel. Now look at what's below a female flower's corolla, at http://www.backyardnature.net/n/17/170827br.jpg

That spiny inferior ovary already is looking like a Balsam Pear fruit.

Thing is, even our small fruits are too bitter or at best tasteless to add to meals, so, the fruits just dangle there delighting visitors with their strange and colorful appearance, but soon splitting open, rodents and birds eat some, and then most just fall away. That makes room for more, for the vines are as prolific as they are underutilized.

*****

ROOTING CLIMBING SPINACH SPROUTS
At http://www.backyardnature.net/mexnat/basella.htm we look at Climbing Spinach, potted plants of which our friend Jerry gave us during a visit to his Neem farm southwest of Mérida, in August. Now my vines are over seven feet long (2m), with vigorous side-sprouts, and it's clear that this is a plant we need to grow more of. It's one of few garden plants the Maya don't already grow, but which thrive during the rainy season, despite the season's insects and diseases.

On the Internet I saw that cut sections of Climbing Spinach roots easily if root-grow hormone is used. Here we have no root-grow, so I experimented with placing the bottom ends of stem sections in water. The sections averaged about 15 inches (38cm) in length. You can see my experiment using a discarded Styrofoam cooling container at http://www.backyardnature.net/n/17/170827cs.jpg

After a week with each stem partly submerged in water, about half of the stems developed rootlets on the submerged parts, as shown at http://www.backyardnature.net/n/17/170827ct.jpg

The picture shows one of the most robustly rooting stems; most stems were too weakly rooted to think of potting. I did pot the one in the picture, and five days later the sprout was growing nicely. In the picture, notice that rootlets arise all along the stem, not just at nodes where leaves arise, as is the case with many plants. Also, I found that stem sections cut only at the base but with growing terminal shoots produced more roots than sections cut at both ends.

The mother vine had produced some side sprouts that fell to the ground and rooted. Those rooted sections were cut and transplanted into pots. However, they died and now I believe it was because I'd let the pots receive too much sunlight. This time I've kept the newly potted rooted sections in continual shade and they've all survived. I'll be gradually moving the transplanted sprouts into more sunlight before planting them in their permanent spot.

Our first plants were placed so they could climb a trellis-like affair constructed from tree limbs. However, the plants didn't want to climb at all, despite their common name, so this time I'll be planting them in a flat bed where runners can root wherever they touch the ground, and thus be less vulnerable to water shortages and accidental stem damage.

*****

NEGRITA'S NIPS
The black dog Negrita snarled, lunged at and nipped the famously edible and defenseless Hairless Mexican Dog Chichan Ch'o', profiled at http://www.backyardnature.net/mexnat/xolo.htm

Until now, Negrita had been bottom dog here because she was young and arrived in the hut pack last. But now she'd grown, her canine teeth were well developed, and she was making her first move up from bottom to second-from-bottom dog.

That day, Negrita's flash of aggression and violence seemed out of place in this environment I like to think of as quiet and peaceful. But then I thought better.

For, those yellow butterflies flitting so prettily above the Papaya orchard down below regularly are attacked by flycatchers. But the butterflies themselves, in their larval stage, are guilty of ravaging leaves of countless herbs, bushes, vines and trees. However, those plants defend themselves with herbage normally containing at least a few toxic compounds that hurt or kill caterpillars and other herbivorous animals. The plants also fight among themselves, competing for sunlight, water and nutrients. Their roots constantly invade one another's underground spaces, sometimes exuding allelopathic compounds that kill or retard the growth of nearby plants. On and on this could go, finding aggression and violence around me, for even microbes battle one another, only the fittest surviving.

Thinking like this, I seem to be the only one here just peacefully sitting, not engaged either in attacking or defending. However, my very presence and manner of being here is made possible only by taking advantage of acts of aggressive and violent exploitation of others. That violence includes converting forests and prairies to chemical-doused agricultural land, and having great ships spew diesel fumes into ocean air between here and where my camera, computer and shortwave radio come from.

So, yes, when you start thinking about it, aggression and violence run through everything everywhere. And yet, there's a broader pattern to consider.

For, the most violent, aggressive act of all time, the Big Bang, resulted in a Universe of unspeakable majesty. The Earth formed by coagulation and gravitational contraction of a cloud of gas and dust around the Sun in a process so violent that now ±4.6 billion years later most of the Earth's interior continues to be magma seething from the heat of formation, yet look how beautiful the Earth is. And on Earth itself, for maybe four billion years life has evolved according to Darwin's "survival of the fittest," a strategy involving such aggression and violence that 99.9% of all species that ever existed now are extinct. But, that strategy has produced this planet's gorgeous forests, fields, oceans, and -- here's something -- beings with evolving mentality potentially capable of ordering life without aggression and violence.

So, that's the pattern: That at any given moment, all seems aggression and violence, yet the long-term trend is toward exalted states, possibly even some kind of peacefulness. Something is going on here we can't figure out, but would do well to reflect on, if only for a certain peace of mind during times when there seems to be no peace or high-minded impulses at all.

*****

Best wishes to all Newsletter readers,

Jim

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