August 10, 2014
GARDEN SPIDER
Nowadays a large, common, conspicuous spider is showing up from southern Canada all through the US and Mexico into Central America. It's the Garden Spider, ARGIOPE AURANTIA, whose body measures about an inch long (25mm), with legs spreading across a much larger area. We've observed Garden Spiders nearly everywhere we've gone, and they occur here, too. You can see one hanging in her web beneath a shelter at Cook's Slough Nature Park on Uvalde's south side at https://www.backyardnature.net/n/14/140810ag.jpg.
If you closely compare that picture with one we took in the Yucatan, found at https://www.backyardnature.net/n/10/100829gs.jpg, you'll see subtle differences in color, patterning and body shape. For example, the one in the Yucatan, has completely black legs, while the legs of our Cook's Slough one are yellowish at their bases. Most species occurring over such an extensive distribution area display regional differences inspiring experts to define subspecies, or even to debate whether they might actually represent different species.
However, I can't find reference to our Garden Spider having subspecies. Still, I bet someone someplace someday will be glad to see photos of Garden Spiders from out-of-the-way places, so I gladly post here a view of our Cook's Slough spider's undersurface, at https://www.backyardnature.net/n/14/140810ah.jpg.
And a close-up of the body at https://www.backyardnature.net/n/14/140810ai.jpg.
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CADDISFLY LARVA
To the imaginative individual with both a healthy measure of ignorance and visual impairment, such as I, the world is even more mind boggling and mysterious than to a normal person. For example, the other day in the barely trickling waters of the upper Dry Frio River I picked up a submerged limestone rock just to see what aquatic being might be stuck to its bottom. My mind could not reconcile what I thought I saw and what I knew of aquatic animals.
For, it seemed that a juicy, green caterpillar clung to the rock's undersurface, though I'd never seen an aquatic, juicy, green caterpillar. Certain fly-type insects, such as horseflies, metamorphose through an aquatic, wormy stage, but those larvae look more like maggots than caterpillars. Caterpillars are larvae of moths and butterflies, and I have read of aquatic caterpillars, but so far I haven't consciously seen one, much less such a succulent, green one.
Moreover, it seemed that the fat, green caterpillar was being dragged by the head across the wet rock by a black ant, and I certainly have not heard of aquatic ants. I photographed this mystery, and when finally the image was on the laptop screen, at least part of the mystery was solved. You can see the image at https://www.backyardnature.net/n/14/140810cf.jpg.
The "black ant" was the caterpillar-thing's front end. But, I'd never seen a caterpillar designed like that, either, much less an aquatic one.
Some creative Googling finally clarified matters.
Until now my experience with caddisfly larvae had been that in running water they occupy cone-shaped, bagworm-like cases to which tiny twig fragments adhere, providing camouflage and armor. I had been looking for such a case beneath the stones I was picking up that morning. Well, despite my experience with caddisfly larvae in submerged, bagworm-like cases, our "green, aquatic cateripllar" was a caddisfly larva.
Since caddisflies constitute one of the largest groups of aquatic insects, with about 7,100 described species worldwide and some 1,340 species in North America, and their larvae have adapted to a huge range of different microhabitats, it should be no surprise that all caddisfly larvae don't fit my one stereotype.
Since caddisflies are neither moths nor butterflies, their larvae are not caterpillars -- though caddisflies are closely related to butterflies and moths, so their larvae have a right to look like caterpillars. However, caterpillars bear many appendages, called prolegs, along their abdominal segment, but caddisfly larvae have only a single pair located near the tip, or rear end, of the abdomen. They also bear various kinds of bristles and exterior gills, but none of those features show in our image.
With so many species I can't say which one our picture shows. However, a common, widely occurring species found in our area and whose pictures look exactly like ours is MACROSTEMUM CAROLINA, so that's how I'm filing our picture and information here, until an expert informs me otherwise. Sometimes, because the adult's wings are blotchy black-and-white, this species is known as the Zebra Caddisfly. It occurs in the US Southeast, as far west as Texas and up the eastern coast as far north as New York.
Instead of the bagworm-like larva case I was familiar with, the Zebra Caddisfly builds a silken canopy over a small natural depression or gouging in a submerged tree branch or snag, orienting the canopy's water intake and outflow holes so that water currents carry suspended food into the chamber to the hungry caddisfly larva. Most kinds of caddisfly larva are herbivorous scavengers, feeding mainly on fragments of plant material, living vegetation, and other living and dead organisms
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AN AMAZING HIBISCUS-FAMILY MEMBER
Since I can't explore the hills all around us because they're private property bristling with no-trespassing signs, I've just about given up hope of finding new wildflowers alongside the single little road I bike up and down the Dry Frio River Valley, week after week. Therefore you can imagine my delight when this week something completely new turned up, and it wasn't even one of the many look-alike species of yellow-flowered daisies so easy to overlook, but rather something unlike anything I'd ever seen. You can see the knee-high plant leaning toward the road's sunlight from below an Ashe Juniper at https://www.backyardnature.net/n/14/140810he.jpg.
A close-up of some flowers and immature fruits is at https://www.backyardnature.net/n/14/140810hf.jpg.
At this point I was already pretty sure that we had a member of the Hibiscus Family, for the herbage and growth form look like any number of members of that family, plus such five-cornered fruits are common in the family, though I don't recall any as spiny-margined as these apparently are. An even closer look, showing most parts densely covered with hairs is at https://www.backyardnature.net/n/14/140810hg.jpg.
This close view was confusing, especially the immature fruit at the right. Those pale, banana-shaped items occupying the sinuses between the fruit's five "wings" are the stamens' pollen-producing anthers. The most important field mark of the Hibiscus Family is that stamens in that family normally are numerous, with filaments uniting at their bases into cylindrical "staminal columns" surrounding part of the female pistil. But this flower appears to possess only five stamens and there's no conspicuous staminal columns. You might like to compare our plant's stamen arrangement with a more typical staminal column surrounding the style of a hibiscus flower in Mexico, the column bristling with the stamens' cream-colored filaments and yellow anthers at https://www.backyardnature.net/n/11/110109hj.jpg.
The Hibiscus Family is huge and is home to some real oddities, but could it accommodate such departures from the norm as this? I looked even closer at the fruit, shown at https://www.backyardnature.net/n/14/140810hh.jpg.
Here we see that the hairs covering the five-winged fruit are many-pointed compound ones, looking like like spiny sea-urchins -- they're "stellate" hairs. However, stellate hairs are to be expected in the Hibiscus Family and some closely related families.
Another point of confusion was that I had interpreted the small, drooping flowers as immature, later to open into blossoms more typical of the Hibiscus Family. However, a closer look showed that mature flowers remained tiny and tube-like with narrow openings pointed downward, ready for pollinators, as seen at https://www.backyardnature.net/n/14/140810hi.jpg.
A side view of the same flower from the side is at https://www.backyardnature.net/n/14/140810hj.jpg.
Breaking open a flower brought even more confusion. You can see why at https://www.backyardnature.net/n/14/140810hk.jpg.
Outermost there's the green, hairy calyx where it's supposed to be. Just inside that there's the colored corolla, also properly situated. But then at the flower's bottom, in the center, there's a stem atop which it appears to be the egg-shaped ovary, but that ovary seems to be enveloped with the greenish petals of a second corolla. This is unheard of. It didn't start making sense until a more mature fruit was bend over, revealing a little stem below it, shown at https://www.backyardnature.net/n/14/140810hl.jpg.
Now I understood. The innermost "green corolla" was actually flattened filaments of the five stamens, with their anthers fallen off. In the above picture the brown anthers are still attached. Moreover, now it looks as if the filaments really do unite into a staminal column surrounding the base of the ovary/fruit. Now it seeming like the Hibiscus Family again.
Still, I'd never seen anything like this, and when I looked at all species in the Hibiscus Family found in Texas, there was nothing like this. That list is at http://botany.csdl.tamu.edu/FLORA/Wilson/checklist/b301mlv.htm.
To shorten the story, which took some time to work out, our plant is HERMANNIA TEXANA, in the whole world found only in southwestern Texas and adjacent northeastern Mexico. In books it's variously known as Texas Burstwort, Mexican Mallow and Texas Hermannia, but these seem to be made up by editors. I don't believe it has a good English name, but I'll use Texas Burstwort just for the pleasure of using the word "burstwort."
Our Texas Burstwort is not included on Texas A&M University's Checklist of Texas plants because Texas A&M's experts consider it a member of the Cacao or Chocolate Family, the Sterculiaceae. However, recent genetic studies indicate that the Cacao Family is inseparable from the Hibiscus Family, so now most experts place Hermannia among the hibiscuses. The confusion just highlights Hermannia's peculiarities.
The genus Hermannia is mainly South African, but a few species, like ours, live scattered around the globe. Just about everything known about the genus is found at http://www.malvaceae.info/Genera/Hermannia/Hermannia.html.
Texas Burstwort is described as growing in dry, rocky, calcareous or gypseous soils of the Edwards Plateau and the South Texas Plains.
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LAMBSQUARTERS
Along trails through Cook's Slough Nature Park on Uvalde's south side and along roadsides, up against fences, etc. , nowadays there's a weedy plant that, especially after midday when it's starting to pucker and twist because of the dryness, is so unspectacular, spindly and scrappy looking that if you're really hot and sweaty and looking for shade, you're more likely to pass it by than take a closer look. You can see one of these exceptionally homely-looking weeds at https://www.backyardnature.net/n/14/140810ch.jpg.
Even with this distant glance, the manner by which its top branches end with unkempt, elongate clumps of tiny, greenish, granular items, someone familiar with weeds might recognize this as Lambsquarters, Chenopodium album, a common weed throughout North America, and famous for its young stems and leaves being eminently edible when cooked like spinach. However, these Cook's Slough plants were taller, more diffusely branched and more wiry than the Lambsquarters I'm accustomed to back East, so I took a closer look. The flowering heads certainly looked like the East's Chenopodium album, as shown at https://www.backyardnature.net/n/14/140810ck.jpg.
Those flowering heads consist almost entirely of flower buds, not open flowers. However, on one plant in the shade a few buds were open, so you can see that the tiny flowers consist of a corolla-like, five-parted calyx heavily coated with tiny, white, gland-like hairs -- there being no corolla -- and the five stamens arise opposite the calyx lobes, or sepals, at https://www.backyardnature.net/n/14/140810cl.jpg.
All this is hardly indistinguishable from the Lambsquarters I so frequently eat back East. However, the leaves look different. Leaves of these Texas plants strike me as being, on the average, smaller and more deeply toothed, as shown at https://www.backyardnature.net/n/14/140810ci.jpg.
Like the Lambsquarters back East, the leaves are heavily covered with a white mealiness, as shown at https://www.backyardnature.net/n/14/140810cj.jpg.
Surfaces covered with such white mealiness are said to be "farinose," the word farinose being based on the Latin farina, which simply means ground corn or flour, or meal.
So, our Cook's Slough plants are Lambsquarters, but they're a different Lambsquarters species from the abundant one I've so often eaten. Our Cook's Slough plants are CHENOPODIUM BERLANDIERI, occurring throughout North America, though most commonly in the west and central parts, and curiously absent from most of the US Southeast, but extending southward from here through northern and central Mexico.
Our Cook's Slough Lambsquarters goes by several names, such as Pigweed, Pitseed Goosefoot and Huauzontle. And, amazingly, this Lambsquarters species is a very important one in terms of its contributions to native American cultures. For, Chenopodium berlandieri is one of only four plants that were domesticated in the Eastern Woodlands of North America prior to the introduction of corn, or maize. Archaeological evidence shows that the species was extensively foraged by people in eastern North America as early as 8,500 years ago. By 3700 years ago the plant had been domesticated.
Nowadays a cultivar of our plant, Chenopodium berlandieri subsp. nuttalliae, originally grown in Mexico, is grown commercially for its green and red foliage and is served in salads at restaurants under the name Red Aztec Spinach. In Mexico other cultivars of this same subspecies are still grown for their edible grains.
You may be interested in Daniel Robinson's Masters Thesis at the University of Tennessee, "Chenopodium berlandieri and the Cultural Origins of Agriculture in the Eastern Woodlands," available for free on the Internet. To find it, search on the title.
Though the Lambsquarters at Cook's Slough were too mature and thus too tough, I read that earlier in the year the young plants and sprouts of this species are just as good to eat as the Lambsquarters I'm used to in the East. That makes this a plant to know, and to wait for next spring.
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MORNING GLORY
Back in the Yucatan at this time of year, just as the rainy season is seriously getting underway, the gorgeous diversity and sheer numbers of morning glory vines staggers the sensibilities. How I used to love roaming the backroads on my bike, the never-ending variations on morning-glory themes like an unending fugue expressed in terms of roadside weeds.
Here it's too arid for any kind of lushness, particularly of the extravagant, sprawling, morning-glory kind. We do have Texas Bindweeds entwining their tough stems in wire fences, and they're members of the Morning Glory Family, the Convolvulaceae, but their smallish, white flowers can be lost in an afternoon's sun-glare, and their tough, pinched little leaves, only partly satisfy one's morning-glory craving.
But, then this week a genuine morning-glory sonata turned up in a pretty thicket of Cowpen Daisies next to the house of my neighbor Phred, shown at https://www.backyardnature.net/n/14/140810ip.jpg.
Note the heart-shaped leaves. The vividly blue blossoms were about two inches across (5cm) with white eyes fringed with a kind of day-glow pale purple or lavender.
This species is not normally found growing wild in this part of the world, though that's what it seemed to be doing among Phred's wild daisies. However, last year Phred sowed around his house a package of seeds marketed as a "morning-glory mix." This resulted in lots of morning glories with flowers of various colors twining prettily among his sunflowers. I suspect that the ones we're looking at now must be "volunteers" from seeds that somehow traveled a few feet from their parent vines, and this year have been encouraged by Phred's frequent waterings of his wild daisies. As such, probably they're more "cultivated" than "wild growing."
Hundreds of viney species known as morning glories are scattered among various Morning Glory Family genera, and sometimes it can be hard to identify a plant to species. Therefore, to be sure about what you have, you must "do the botany." You can see one of our flower's white, slender, funnel-shaped corolla tubes at https://www.backyardnature.net/n/14/140810iq.jpg.
A closer look at the calyx is shown at https://www.backyardnature.net/n/14/140810ir.jpg.
In that picture we see that the slender sepals partly overlap one another and are of different lengths. Below, they bear long, sharp, upward-turned, white hairs. These are all important field marks needed to determine the species.
During the blossom analysis, I didn't forget to pay attention to the pure beauty of the blossoms' colors. Just look at one view enjoyed at https://www.backyardnature.net/n/14/140810is.jpg.
A longitudinal section of a blossom reveals that not only are the five stamens of very different lengths, but also that the stigma at the tip of the long, slender style is more or less spherical, though somewhat flattened. You can see this at https://www.backyardnature.net/n/14/140810it.jpg.
Such a roundish stigma helps us peg our morning glory as a member of the genus Ipomoea, the largest and most important of the Morning Glory genera, comprising over 500 species, among which the Sweet Potato is a very important member.
All the above field marks, especially the heart-shaped leaves, sepal shape and disposition, the forward-projecting hairs and the blossoms' white "eyes" giving way to a bluish outer corolla, lead us to IPOMOEA PURPUREA, commonly known as the Purple, Tall, or Common Morning Glory. If you do an image search on "Ipomoea purpurea" you'll see that the species' blossoms come in several colors, from deep blue to purple to rose, pink and white. Cultivars with white flowers ornamented with colored stripes also are available. However, the basic field marks remarked on here remain the same throughout the many cultivars.
Ipomoea purpurea is native to central and southern Mexico, though it's found growing in gardens as well as in the wild across North America, often "escaping" just like it apparently has at Phred's. However, as soon as Phred stops watering, I'll bet his morning glories will disappear.
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THE DRY FRIO IN SUMMER
Early this January a certain stretch of the Dry Frio about two miles north of Juniper House in Real County was pictured here so you could see what the landscape looked like in mid winter. That picture is still online at https://www.backyardnature.net/n/14/140105fr.jpg.
In April we took the same shot so we could see the changes. Our spring picture is at https://www.backyardnature.net/n/14/140427fr.jpg.
This week I took our summer picture, and it's at https://www.backyardnature.net/n/14/140810fr.jpg.
The change isn't nearly as striking as it would be farther east where more rainfall permits a greater diversity of plants, with different responses to the changing seasons. Still, there are changes, subtle ones, and it's a pleasure to savor these variations on a seasonal theme.
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FEATURED ESSAYS FROM THE PAST:
"Thoughts about Animal Rights" from the March 14, 2004 Newsletter, at https://www.backyardnature.net/n/p/040314.htm
"The Sign" from the October 15, 2007 Newsletter, at https://www.backyardnature.net/n/p/071015.htm
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Best wishes to all Newsletter readers,
Jim
All previous Newsletters are archived at https://www.backyardnature.net/n/.
