December 7, 2018

MEXICAN TREEFROG OF A DIFFERENT COLOR
At https://www.backyardnature.net/yucatan/treefrg1.htm we see several variations in the appearance of our most commonly occurring treefrog, the Mexican Treefrog. This week Genesis volunteer Daniel Leyva photographed a phase of that species at Genesis so different from what I've seen so far, that at first I didn't recognize it. Daniel's picture is at https://www.backyardnature.net/n/18/181207tf.jpg

The frog, perched on a leaf, is lit by a flashlight, so it's hard to judge what it might look like in daylight. Still, it seems mostly greenish and there's a bright, bluish spot connecting the eye with the upper lip. One of the frogs on our web page displays a slightly bluish spot there, but nothing so outstanding.

It's surprising how variable this frog is. We've seen a brownish one matching the murky brown pond-water it was calling from. A green-and-dark-gray one matched splotches the gray limestone rocks with patches of greenish algae it perched on. One in a tank with a white interior was light gray. And now we have this green one on a green leaf.

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DONKEY EARS FLOWERING
About 20 months ago when I was visiting a friend near Tepotzlán in the arid Mexican highlands south of Mexico City, one of my friend's ornamental plants caught my eye because it was the largest broadleaf succulent I'd ever seen in a pot, with broad leaves two feet or more long (60cm). Along the leaves' scalloped, or "crenate," margins, tiny rosettes of leaves arose at each indentation. It was one of many kinds of "airplant" capable of vegetative reproduction via the leafy rosettes, which can grow into new plants. Similar plantlet-bearing flat leaves on an another airplant species, an invasive sometimes seen in the Yucatan's woods, is shown on our page at https://www.backyardnature.net/mexnat/airplant.htm

On that page we learn that in this group of plants reproductive rosettes of leaves can occur on the margins of larger leaves because the larger leaves aren't leaves at all. They're "phylloclades," which are highly modified stem branches functioning as and looking like leaves. Vegetative offshoots on a stem make sense, but not on the margin of a real leaf.

The airplant introduced on our earlier airplant page, with phylloclades that were often compound, was different from the one at my friend's house in Tepoztlán. I plucked three aspirin-size buds from one of its phylloclades, put them in my pocket, and carried them to the rancho, where I planted them in pots. After 20 months, you can see one of the resulting belly-high plants, at https://www.backyardnature.net/n/18/181207kc.jpg

In that picture, notice the whitish rosettes at tips of the lower phylloclades, and the absence of rosettes from blade margins. This surprised me, because I'd removed my rosettes from phylloclade margins. But then a fallen-off blade that had been cut in two turned up, with rooting rosettes arisen from the margins like my Tepotzlán ones, as shown at https://www.backyardnature.net/n/18/181207kd.jpg

Maybe, under our hotter, drier Yucatan conditions, phylloclade-tip plantlets arise, while in the cooler, gardener-attended environment at Tepotzlán, margin ones are more likely.

It was the flowers I'd been waiting for mostly, however, needed for me to "do the botany" using my old Bailey's Manual of Cultivated Plants. Bailey's got me as far as the genus Kalanchoeë in the Orpine or Crassula Family, the Crassulaceae, but among the ten species of Kalanchoeë he considers, none was our Tepotzlán plant. On the Internet, after trying various combinations of key words with the Google Image search engine, pictures matching our plants turned up answering to the not-very-technical query "giant Kalanchoeë."

Our Tepotzlán garden plant is KALANCHOË GASTONIS-BONNIERI. Among its English names, Donkey Ears seems to be the most frequently used, along with Life Plant, but that latter name is used for many similar species. Donkey Ears is a native of northwestern Madagascar, but it has escaped from gardens in many tropical countries, and often has become invasive.

The plant's flowers are very distinctive. A close-up view of the flowering head, or inflorescence, is shown at https://www.backyardnature.net/n/18/181207kb.jpg

In that picture the yellowish flowers dangle amid pinkish, egg-shaped items. A close-up view of the oval things seen from above the plant is shown at https://www.backyardnature.net/n/18/181207ke.jpg

These are "inflated" calyxes. In most flowers the calyx is a green, inconspicuous, cup-like thing below the colored corolla, but inflated calyxes are fairly common in the genus Kalanchoë. Among Bailey's ten species, half produced flowers with inflated calyxes, while calyxes of the other half were only a little or not at all inflated, so the inflated calyx is an important field mark when dealing with the genus Kalanchoë.

For three or four weeks before the first corolla emerged from its inflated calyx, the clusters of bladdery calyxes were just as ornamental as flowering heads, if not more so. When light shined on the calyxes' smooth, somewhat waxy surface, the effect was very striking. You can see a yellowish corolla fully emerged from its subtending calyx at https://www.backyardnature.net/n/18/181207kf.jpg

Notice that the corolla is slightly curved. A view from the flower's front shows that it's also flattened, with an upper and lower "lip," seen at https://www.backyardnature.net/n/18/181207kg.jpg

In that picture, the rose-colored, pear-shaped items are pollen-producing anthers atop their slender, yellow filaments. In total, the flower had eight stamens of different lengths, so the other stamens' anthers are hidden inside the corolla.

Among Kalenchoë species with inflated calyxes, the next big feature to notice is whether the corolla is "contracted," or pinched into a narrow waist, at its base. With one side of the calyx removed the answer is obvious, seen at https://www.backyardnature.net/n/18/181207kh.jpg

This is a classic Kalenchoë contracted corolla base. With the corolla removed, we can see the flower's four pistils and several of its eight stamens, at https://www.backyardnature.net/n/18/181207ki.jpg

Another important field mark for this particular species is the way the plant's leaflike phylloclades attach to the main stem. The phylloclades' blades connect with the main stem opposite one another, via flat petiole-like parts that expand at their bases to completely encircle the stem with a kind of collar. It's easy to believe that such strange arrangement is something other than regular leaf petioles attaching to a stem. You can see it all at https://www.backyardnature.net/n/18/181207kj.jpg

Most pictures of Kalenchoë gastonis-bonnieri show blades conspicuously marked with dark blotches, while our plants display only hints of them. I wonder if these markings develop only on sheltered plants such as those usually grown and photographed by temperate-zone gardeners, while our plants have dealt with nearly two years of tropical heat, sunlight and a hard dry season?

The other Air Plant linked to above we placed in the genus Bryophyllum, not Kalenchoë. In fact, some authors currently call our Tepotzlán plant Bryophyllum gastonis-bonnieri. Many species in this group have been switched back and forth between Kalenchoë and Bryophyllum. I don't know what the best name is, and see no differences between the two genera.

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EATING MAKAL TUBERS
At https://www.backyardnature.net/mexnat/makal.htm we look at Makal, a cultivar of the giant Elephant Ear, Xanthosoma sasgittifolium. Traditionally, Makal has been an important starchy rootcrop for the Maya and other indigenous American societies. Last month I described how I'd eaten Makal leaves and stem sections, though those parts are not considered the most important edible part. This week I've eaten the tubers, which are exactly what traditionally Makal has been grown for.

Gener, one of the Maya workers at the rancho, showed me how his family unearths Makal's tubers. You can see Gener's hands exposing a potato-like tuber beneath a Makal plant at https://www.backyardnature.net/n/18/181207mk.jpg

A washed tuber is shown at https://www.backyardnature.net/n/18/181207ml.jpg

You can see that the tuber, just like a potato, bears "eyes" on its sides. If the tuber is cut into several sections, with each section bearing an eye, the eye will sprout and produce a new plant, also as with potatoes. Sometimes Makal tubers are roasted in fires, or sliced and fried in skillets, or boiled in pots, all as with potatoes. One difference between Makal tubers and potatoes is that Makal tubers are toxic until they're cooked.

I boiled my tubers and found them filling, with their own subtle, homey taste, but not as tasty as potatoes, though that may have been a cultural bias. Each plant, if grown in rich soil and watered regularly, produces several tubers -- enough to make it worthwhile for people to grow them.

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PAVONIA FLOWERING
Last September 30th during my camping trip into northern lowland Guatemala's Petén district, in El Rosario National Park on the eastern side of Sayaxché, a knee-high weed along a shaded dirt trail through the woods bore a single white flower, as shown at https://www.backyardnature.net/n/18/181207pv.jpg

The plant had a tough, wiry, semi-woody and much branching base, and the leaves, though thin-bladed, also were tough and somewhat brittle. The blossom immediately revealed which plant family this belonged to, as you can see at https://www.backyardnature.net/n/18/181207pw.jpg

With such pollen-releasing anthers clustered atop a slender tube formed by the stamens' fused filaments encircling the ovary's style, it has to belong to the big Hibiscus Family, the Malvaceae. A view from below the blossom shows another feature of that family, at https://www.backyardnature.net/n/18/181207px.jpg

Flowers in the Hibiscus Family often have beneath their calyxes clusters of modified leaves called bracts. In the above picture the white corolla arises from a pale green calyx with five sharp-pointed sepals, and below that calyx arise eight long, slender, sharp-tipped bracts, forming an "involucre." Every hibiscus flower exhibits the same structure.

The Hibiscus Family is so big that even with flowers I doubted being able to identify this plant. In this family, often the fruits are needed, because -- different from many or most families of flowering plants -- there's greater easy-to-see variability among the fruits than the flowers. And then I saw that the plant bore an old fruit. The mature fruit broke into five fruit-like "mericarps," each mericarp topped with three barbed spines, as shown at https://www.backyardnature.net/n/18/181207py.jpg

These details were sure to reveal the plant's identity.

Many members of the Hibiscus Family, such as that of cotton and hibiscus itself, produce capsular fruits that do not break apart in this manner, so this fracturing fruit disqualified a lot of possibilities. The flower in our first picture also displayed a feature eliminating a very large number of genera: The white, baglike, pollen-producing anthers arose not at the very tip of the staminal column, but a bit below it.

These and other features led to the genus Pavonia, which is one of the largest genera in the Hibiscus Family, with 24 species listed for Mexico alone. With the help of Paul Fryxell's 1979 "Una Revisión del Género Pavonia en Mexico," and having those three-spined mericarps handy, it was easy to determine that our plant was PAVONIA SCHIEDEANA, one of the more widely distributed species, found from central Mexico and the Caribbean south through Central America into South America. In Spanish sometimes it's called Cadillo, but there is no good name for it in English, though Pavonia makes a pretty one, and is good enough for us here.

Having the name Pavonia schiedeana, we can look up the plant and see what's interesting about it.

In Mexico traditionally the species has been used in hair care. It's supposed to keep hairs from falling out, and prevents dandruff. It's also used to speed up childbirth, and to prevent abortion. It's been considered good for indigestion, diarrhea and the fever. For the fever, the stems and leaves are cooked, and the resulting liquid is used to bathe the patient, and injected into the rectum. Sometimes it's also been used for kidney problems, diabetes and bronchitis. In pharmacological studies, beta-sitosterol and tannins have been isolated from the roots.

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MISTLETOE CACTUS FRUITING
Last October 4th during my camping trip to Mexico's southernmost state of Chiapas, in Maya Bell Campground near the ruins of Palenque, the trunk of a large tree was fairly covered with vine stems, creeping aroids, orchids, bromeliads and, in one place, a dangling, un-cactusy-looking cactus, as shown at https://www.backyardnature.net/n/18/181207rh.jpg

Normally I need both flowers and spines to identify a cactus, but this species bore neither. Still, its general appearance was so unique that the species is famous among cactus connoisseurs, and many know it by sight. One English name for the species is Mistletoe Cactus. It's RHIPSALIS BACCIFERA, native to Mexico, and as a handsome novelty often grown as an ornamental elsewhere.

In the above picture, notice that many of the cactus's dangling stems are tipped with something pea-sized and white. Those are fruits, a ripe one emerging at a stem node seen at https://www.backyardnature.net/n/18/181207rj.jpg

Technically, the small fruit is a berry, meaning that it's fleshy with more than one seed. Traditionally such fruits have been collected for eating. I find them a little tasteless, but they make nice nibbling while walking around. In the Cactus Family, the Cactaceae, flower ovaries are inferior, meaning that the calyx, corolla and sexual parts arise above the ovary instead of at its base. That explains the blackish item at the fruit's far end, which is the dried, shriveled-up calyx. I looked for flowers, but they were all gone. However, one immature ovary still bore the semi-dried-out remains of a flower, shown at https://www.backyardnature.net/n/18/181207ri.jpg

Something interesting about that picture is that mature Mistletoe Cacti are described as usually spineless, but at the base of the above ovary you can make out some minute barbs, maybe even a branched one.

Something else interesting about this species is its distribution. The entire Cactus Family is almost exclusively native to the Americas. Pricklypear infestations in the Mediterranean area, Australia and elsewhere are weedy invasives from the New World. The "almost" in the above "almost exclusively native" is due to the Mistletoe Cactus. It's the only cactus species naturally occurring in the Old World. Its entire native distribution area ranges from Florida and the Caribbean south through Mexico and Central America into most of South America, as well as southern Africa, Madagascar and Sri Lanka.

It's an unsolved mystery how the Mistletoe Cactus accomplished this. The two main theories are: Somehow the plants got across the Atlantic, as by seeds carried by birds in their guts, and; The species separated into two populations when Continental Drift parted the Americas from Africa. It's also possible that during the 1500s sailors carried the cacti or seeds across the Atlantic, then birds quickly disseminated the species over a large area so that it just seemed to the earliest botanical explorers that it was native to Africa and Asia.

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"ADEQUATE"
During the months since I reviewed the philosophy of Baruch Spinoza (1632-77), a single word from his writings has emerged in my mind as representing what was, to me, his most important concept. That word was "adequate." Joseph Ratner, editor of the edition of Spinoza's writings I read, spoke of Spinoza's belief in "the adequacy of the natural powers of our mind to understand the mysteries... of heaven and earth."

This concept is important because many agencies, particularly religions, power structures and political parties, don't want regular people thinking for themselves. A person is supposed to have "faith" in some prepackaged belief system, or follow the party line, or simply think what you're told to think, else you'll have trouble.

I've been thinking about this because I'm more and more convinced that at this stage in human social evolution -- especially because of the Internet and social media -- we humans finally have enough scientifically based information and enough of the thoughts of geniuses throughout the ages, that we no longer need prepackaged belief systems, party lines, and orders from the top. It's time for each of us to consciously and individually formulate our own opinions about the big questions -- "the mysteries... of heaven and earth."

Part of the problem is that the radiant, golden nuggets of scientifically established facts and profound philosophical insights are awash in oceans of wishful thinking, pseudo-science, propaganda and advertisements, repeated and repeated. Religions, governments and the like have the money to propagandize their points of view, while we peons seldom do.

In that context, I'll share with you a process I've stumbled onto enabling the winnowing out of false and misleading information and thoughts, from the good stuff. Mostly, the method consists of being as intimate with Nature as possible. My own personal technique for doing this has been to identify lots of plants and animals, hike and camp in beautiful areas, be alone, do my best to refine my sensitivities, and to pay attention to everything. Other people have different paths, maybe teaching children about Nature, maybe painting watercolors of flowers, or gardening. Many wonderful, fulfilling paths are available.

If you're around people who always are negative and complaining, before long you get grouchy and dissatisfied yourself. I'm guessing that that same process, working in a more positive direction, explains how one can be inspirited and instructed by being immersed in Nature. It's a process of osmosis, of a general mood and manner of being being conveyed wordlessly. We can trust these non-verbal messages from Nature because since the beginning of the Universe all Her features have been tested, and all falsity has been winnowed out.

My experience has been that, after spending a lot of time with Nature, when something phony or disharmonious with the general flow of things comes along, it simply doesn't "feel right," and I can avoid it.

This is hardly a rational approach and the messages Nature sends are seldom very precise. However, the system has proven to be "adequate" for me with my "adequate" mind.

*****

Best wishes to all Newsletter readers,

Jim

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