February 21, 2010
ARMY ANTS & ANIS
For the last month most days if you looked around you could find seven or so Groove-billed Anis clustered on the ground or lolling in low perches. You can see four of them displaying their curious air of watchfulness at http://www.backyardnature.net/n/10/100221an.jpg.
At first I figured that they were just being social but after seeing them at different places again and again, usually doing nothing but sometimes making quick pecks into the leaves, and sometimes rushing short distances in a curiously dainty-fast manner, like someone hurrying over crushed glass, it occurred to me that something special might be going on.
Ants were going on. Each day the anis were locating a battalion of foraging army ants. When the ants scared up a grasshopper, a small lizard or other such prety, the anis would try to get the goodies before the ants tore them apart. The trick for the anis was to avoid getting into the ants, for army ants bite anis, too.
Usually I see anis on ranchland where cattle stir up the anis' prey. Clearly to the anis it doesn't matter whether cattle or ants make grasshoppers abandon their shelter; just so they do.
TRUE DEATH'S HEAD
I'd expected a mail from Bea in Ontario passing on the name of an insect she'd identified for me, but when her letter appeared with "True Death's Head" written in the subject box I couldn't imagine what fit of desperation had taken possession of her. As it turned out she was fine, just sending the name of the two- inch long (52 mm), spiny legged critter pictured at http://www.backyardnature.net/n/10/100221cs.jpg.
Seeing the shield-like plate (the pronotum) covering the insect's thorax and back of the head, you might recognize this as a cockroach. It's BLABERUS CRANIIFER, a species native to Mexico, the West Indies and Central America, and introduced into Florida. The one in the picture was found at dusk scurrying along the dry, shadowy bottom of a concrete gutter beside the town square in Valladolid, about half an hour east of here, where I'd gone to pick up new glasses. You can see him in his gutter, displaying the red markings on his pronotum suggesting "Death's Head," at http://www.backyardnature.net/n/10/100221cr.jpg.
The "True" part of the name comes from there being a similar species known as the False Death's Head.
I hadn't expected to find much information about the True Death's Head Cockroach, but it turns out that there's a lot. That's because this is a favorite species for animal collectors, since it's a handsome insect, can't climb glass terrarium walls, has well developed wings but can't fly, doesn't stink unless provoked and then only a little, and is extremely easy to maintain, eating just about anything.
Apparently large numbers of cockroaches under the Death's Head name are sold in US pet stores, as tarantula food. However, I read that most of those are actually a hybrid between Blaberus cranifer and another species. In captivity they live about a year.
TS'IUCHÉ'S WARM, SLEEPY, HAY-FIELD-IN-MAY ODOR
Back in Querétaro, Don Gonzalo introduced us to the sweetly edible white pulp inside the large, curly legume of Guamuchil, Pithecellobium dulce, which becomes available in May at the dry season's end. (next entry) Remembering that good eating, when trees here with leaves seemingly identical to the Guamuchil's turned up, I began looking forward to some tasty meals. This week those trees are flowering abundantly, as shown above.
I mentioned the find to José, supposing that Guamuchil pods must be a big item in Maya cuisine, but was surprised when my description of the legume and its sweet pulp drew a blank from him. Still, he has a name for the tree in Maya: Ts'iuché, if I'm hearing the pronunciation right. However, I'm fairly sure that it's the same tree we saw in Querétaro, PITHECELLOBIUM DULCE.
We're well into the dry season now, with the forest having a crunchy, dusty feeling to it, so Ts'iuché's abundant blossoms caused the 15-ft-tall tree to seem like a spring bouquet in the desert. Untold numbers of honeybees could be heard buzzing from a good distance away. As you approached, the flowers' fragrance was like what you smell walking by a freshly mown hayfield in May -- the sublimely sweet odor that makes you sleepy and almost want to sneeze. A flower close-up is at http://www.backyardnature.net/n/10/100221pj.jpg
These flowers look a lot like acacia flowers. However, if you look with a hand lens as a Pithecellobium's stamens -- the white, hairy things in the picture -- you find that the stamens' stems, or filaments, are joined to one another at their bases, forming a short cylinder around the female parts. An acacia flower's numerous stamens are not connected, and that distinguishes acacias not only from Pithecellobiums but also from members of the important genera Albizia and Calliandra. It's a good field mark to keep in mind.
If you were with me back in Chiapas you may have developed a special fondness for the Frangipani, genus PLUMERIA. You can see that small tree's beautiful flowers, and see how my Tzotzil-speaking friends and I created garlands of them for adorning their altars, at http://www.backyardnature.net/chiapas/plumeria.htm.
We have Frangipanis here, too, and sometimes they're as beautiful as the ones we had in Chiapas. However, this being the dry season and Frangipani being of those trees that loses its leaves in the dry season, our trees now present a completely different side of their character as the did in Chiapas. You can see how at http://www.backyardnature.net/n/10/100221fg.jpg.
Those are Frangipani's thick, stubby, semi-fleshy, leafless branches poking toward a dull, overcast sky this week. Note the branches' curiously bifurcating manner of branching, where a branch sprouts into a Y, then each arm of the Y sprouts another Y, and then those arms sprout other Ys, on and on. Note the T- shaped fruit emerging from a Y's angle at the far top left. Leafless, the tree seems obsessed with artless regimentation. Looking up through the branches I get the same feeling I once had visiting a museum in Germany featuring "Nazi-sanctioned art."
It's good to know that when the rains return once again a soft gorgeousness will drape these hard- disciplined branches.
A pretty wildflower/weed flowering soon after any shower that might come along is the white-flowered one with parallel-veined leaves (it's a monocot) shown at http://www.backyardnature.net/n/10/100221co.jpg.
Northern wildflower lovers will quickly recognize this as a dayflower, or member of the genus Commelina, of the Spiderwort Family, the Commelinaceae. Weakley's Flora of the Carolinas describes seven dayflower species for the region covered by that flora, and those species are fairly similar to the one shown in the picture, which is COMMELINA ELEGANS.
Dayflowers as a group are pretty easy to recognize with their bilaterally symmetrical flowers with three petals, the lower petal being much reduced, as seen at http://www.backyardnature.net/n/10/100221cp.jpg.
Also distinct is how there are six stamens, but with only three being fertile -- their anthers producing pollen. The other three stamens are modified into the sterile, yellow-tipped objects shown in the photo. I'm guessing that the sterile stamens help attract pollinators and provide a hold for the pollinators when they land.
Characteristic of the dayflowers is how several blossoms are cradled within a modified leaf, or bract, folded upon itself at the middle. In the above picture the folded bract is the green, sharp-tipped item occupying the bottom third of the image. You can see a folded bract squeezed open by my fingers to reveal flower buds and an immature flower ready to emerge at http://www.backyardnature.net/n/10/100221cn.jpg.
When you're identifying dayflowers to species level you must pay close attention to the bracts, for some species have the back margins of their bracts joined, forming a kind of cup, while other species are not joined. You can see that this species' rear bract margins are joined.
Another good field mark for this particular species is how the base of each leaf forms a pale, fuzzy cylinder (leaf sheath) around the stem, with a green, triangular pair of earlike "auricles" arising at the juncture of sheath and blade. This can be seen at http://www.backyardnature.net/n/10/100221cq.jpg.
Las Plantas Medicinales de México, which calls the plant Hierba del Pollo, or "Chicken Herb," praises all Commelinas as good for staunching blood, especially for deep wounds and amputations. Chop stems and leaves into a sticky pulp and apply the pulp mass as a compress directly to the wound.
What a pleasure to lie next to this little being, several of whose cousins in the North I've already met, thrusting my mind into these details of color, form, texture and function, remembering how those Northern cousins' details varied, just a little, from this ones', experiencing "variations on a dayflower theme."
A PRETTY MAT OF CALLISIA
In parklike areas where the soil is so thin that flat, white limestone bedrock emerges over large areas, nowadays often you find dense mats of the little, white-blossomed, three-petaled perennial shown at http://www.backyardnature.net/n/10/100221cl.jpg.
That's CALLISIA CORDIFOLIA, usually referred to as Callisia in English, and if its leaves and three-petaled flowers remind you of the above dayflower it's because Callisia belongs to the same family, the Spiderwort Family, the Commelinaceae. You can see a close-up of a flower with its six stamens at http://www.backyardnature.net/n/10/100221cm.jpg.
This flower is similar to a spiderwort flower (genus Tradescantia), and in fact formerly some botanists placed our species in that genus. You can compare the above picture with the North's Zigzag Spiderwort at http://www.backyardnature.net/n/h/spiderwo.htm.
An important difference between the two plant types is that spiderwort flowers are immediately subtended by large, leaf-like bracts, thus looking "stemless" on the plants, while in the photo you can see that Callisia flowers are held on a slender stem (the pedicel), and that the pedicels themselves arise from a larger stem (the peduncle). Also Callisias are much smaller than Tradescantias, the flower in the photo is less than 1/5th inch across (5 mm). A pretty distinction of our species' flowers is that the three sepals arising below the much larger petals bear striking color markings you'd never see if you weren't on your belly looking up from below them, shown at http://www.backyardnature.net/n/10/100221ck.jpg.
So, earlier we had the pleasure of "variations on a dayflower theme." With Callisia we have "variations on a Spiderwort-Family theme." Here we see how within a family the genera can sort themselves out not with the subtle features that distinguish species, but with grosser, more fundamental differences, such as whether large bracts are present below an inflorescence.
The genus Callisia, with its center of evolution here in Mexico, comprises about 20 species, of which seven make it into the Southeastern US. Our Callisia cordifolia occurs from Mexico and Florida south to northern South America.
YELLOW JOYWEED ON THE WALL
Growing from a crack in the church's rear stone wall for months an interesting "weed" has been developing. I've been looking forward to its flowering so I could figure out what it is. You can see it with its flowers at http://www.backyardnature.net/n/10/100221al.jpg.
At http://www.backyardnature.net/n/10/100221am.jpg a close-up shows a flower head. Its most striking features how that it is a short spike in which each flower is subtended by sharp-pointed, papery scales. Whenever you see a flower head with such crammed-together flowers and conspicuous, papery scales, the Amaranth Family should come to mind. Our church-wall plant keys out to ALTERNANTHERA FLAVESCENS, in English often and inexplicably called the Yellow Joyweed. It's a native of Florida and the Yucatan south to the northern half of South America.
If you're familiar with waterweeds of the US Southeast you may see a strong resemblance between Yellow Joyweed's flower head and those of Alligatorweed, Alternanthera philoxeroides, which back in 2003, writing from near Natchez, I described as #1 on Mississippi's list of the Ten Worst Invasive Weeds. Alligatorweed, however, forms dense floating mats on lakes and slow-moving streams. That's a long way from growing from a chink in a church's limestone walls.
For months I've been eating passion fruits off the vines of a nearby stone wall densely overgrown with passionflower vines -- genus Passiflora of the Passion-Flower Family. You can see one of the fruits hanging next to a typical three-lobed leaf at http://www.backyardnature.net/n/10/100221pf.jpg.
Though many species of Passionflower exist and many cultivars are grown for their edible fruits, I'm guessing that our vines are PASSIFLORA EDULIS var. FLAVICARPA. Passiflora edulis has a purple-fruited variety and a yellow-fruited one, and the picture shows the latter, with the fruit just beginning to ripen.
At http://www.backyardnature.net/n/10/100221pg.jpg the fruit has been cut open to reveal its many semi-hard seeds embedded in their pulpy arils. The aril in passion fruits is the outer covering of the seed, and it arises from the seed's hilum or funiculus. The funiculus is the "umbilical cord" connecting the fruit wall with the seed. You can see macaroni-like funiculi in the picture appearing as stalks arising from the fruit's inside wall. A seed's hilum is the scar or mark indicating the point of attachment of the seed with its funiculus. In the US we often run into fruiting Hearts-a-bustin', genus Euonymus, in which the seeds are enclosed in orange-colored aril that attract birds to come eat the seeds and transport them to parts unknown.
Another distinguishing feature of passion fruits is the tough stem affixed at the fruit's base. That stem is what becomes of the stalk upon which a passion flower's ovary perches inside the flower. You can clearly see the ovary's stalk (known as the gynophore) in the second and third pictures on our Passion-Flower page at http://www.backyardnature.net/fl_passn.htm.
Passion fruits are good to eat, though our yellow variety is a bit tart to eat without adding lots of sweetening. A delicious drink is made by blending the fruit pulp with ice, water, sugar, and a pinch of bicarbonate of soda. The juice is an excellent source of Vitamin C.
NOAA'S GLOBAL WARMING PAGE
Jarvis in North Carolina writes to tell about a new US Government website offering a huge amount of information relating to global warming, including charts and graphs documenting how things have changed in recent decades. It's at http://www.climate.gov/.
Jarvis, a retired college professor, was curious about what trends, if any, weather data from his boyhood home in Indiana might show. He writes:
"I calculated mean annual temperature for Salem, Indiana for 1961 through 1970 and then compared that period with later years. This is what I found: 1971-1980: 0.1 Fahrenheit degrees warmer than 1961-1970; 1981-1990: 0.7 degrees warmer; 1991-2000: 0.9 degrees warmer; 2001-2009: 1.2 degrees warmer. So this pattern of temperature change pretty much agrees with the global pattern."
NOTHING IS UNNATURAL
One early morning deep in the woods I stood below a Kikché tree as the day's first breeze stirred. A predawn shower had fallen and leaves were still wet. The breeze shook from the Kikché's leaves myriad silvery water-droplets, which cascaded to the forest floor sparkling as they passed through the day's first beams of sunlight. The droplets were cold and wet, but the sunlight was warm and friendly. Orioles called and a butterfly flitted by. Turning around and around trying to take it all in but not paying attention to where my feet were, my legs crossed, I lost my balance and fell to my knees, keeping myself upright with my walking stick, laughing, laughing.
There on my knees propping myself with the stick, a reflective mood came over me. I'd just experienced a fleeting, magical moment, but now I needed to return to "real life." Here's the thought that came to me: Returning to "real life" didn't really mean that I was "leaving Nature." For, really, nothing is unnatural.
The walking stick supporting me recently had been a tree sapling that had been cut to a certain length, debarked, and now was holding me upright. At what point had that stick stopped being a natural, debarked sapling cut to a certain length, and become an unnatural walking stick? Never, I decided.
The stone church's wall beside me as I type this is made of stone and cement. The cement is fired, pulverized limestone mixed with water, then let dry. It's easy to see that this wall is natural, just that its components have been reconfigured by human hands. The same thinking can be applied to steel, plastic, glass, and even our computers, for all the minerals, petroleum derivatives and electrochemical processes of which those things are made also are perfectly natural, just reconstituted by man and used in novel combinations.
It's worth getting straight in our minds that "nothing is unnatural." That's because if we allow ourselves to believe that humans somehow exist apart from Nature, that somehow we're special, it's easier to imagine that we live according to rules different than those we see governing Nature.
Once we abandon our delusion that the human animal here on Earth has a special deal with the Creator of the Universe, what we see in Nature is sobering. For, we don't see the prayers of trees delivering them from bark-beetle invasions; fish don't conduct rituals resulting in the purification of their polluted streams; no ecosystem produces priests or prophets revealing how practicing a "faith" can save the ecosystem from global warming or nuclear radiation poisoning.
That's the bad news. The good news is that humans are endowed with brains that miraculously enable us to behold in Nature patterns or paradigms upon which we can model our lives. And those patterns when practiced not only can keep our species from self-annihilation, but even enrich us individually and make us happy.
Among the easiest to see and understand of Nature's patterns are those of frugal and simple living, of recycling, of respect for diversity, and cooperative behavior.
Best wishes to all Newsletter readers,