September 21, 2014
TEXAS TORTOISE
On a stretch of white limestone gravel a dark, cobblestone-size item was roaming about this way and that, as if confused or in such a tizzy that a definite route just couldn't be decided on. When I got close enough to see that it was a high-domed turtle -- more correctly a tortoise -- instead of running from me the critter headed my way. I stood still while the wanderer approached my feet, stopped, looked about, and circled my feet as if expecting something of them. You can see the tortoise orbiting my feet at https://www.backyardnature.net/n/14/140921go.jpg.
With such a high top shell, or carapace, and being on dry land, your first impression might be that this is a box turtle, though most box turtles carapaces display pale, often yellow, streaks. But, notice those back legs, like elephant legs, thick and roundish in cross section. And if that doesn't convince you that you have something other than a box turtle, delicately lift the turtle and take a look at the bottom shell, the plastron, as shown at https://www.backyardnature.net/n/14/140921gq.jpg.
Beneath the neck, notice how an extension of the plastron projects forward well beyond the rest of the shell. This projection is called the "gular scute" or "gular projection." No box turtle plastron is anything like this. Also, box turtle plastrons are hinged more or less between the two front legs, so the front can be "drawn up" when the turtle pulls his head in, but there's no hint of a hinge here. And, while we're looking at things from below, note those two, pea-sized bulges on the lower jaw. A closer look is afforded at https://www.backyardnature.net/n/14/140921gp.jpg.
The pea-shaped things are curiously named "mental glands," thought to issue secretions during courtship, helping individuals know who is male or female. Field observations report that when two males are both issuing secretions from their mental glands, normally it leads to combat, often ending with the loser being turned upside-down.
So, here we have a tortoise. A tortoise is different from a turtle in that the term turtle is a general one, applying to all members of the Turtle Order, the Chelonii or the Testudines. But the Turtle Order is divided into families, and the third-most diverse of turtle families is the Tortoise Family, the Testudinidae. Therefore, all tortoises are turtles, but only some turtles are tortoises. Many turtles live in or near water, but tortoises are dry-land turtles.
In Texas, box turtles occur throughout the state, but tortoises are restricted to the southern counties, and there's only one tortoise species in the state. That one, commonly known as the Texas Tortoise but sometimes listed as the Berlandieri's Tortoise, is GOPHERUS BERLANDIERI. Our Uvalde County lies on the extreme northern boundary of its distribution, but toward the south the species extends well into arid northeastern Mexico.
At the TexasTurtles.Org website I read that tortoise nests are called pallets, and that "Tortoise pallets are created by the tortoise using its forelimbs, gular scute and edges of the shell to scrape away an area near the base of a small tree, shrub or clump of cacti." This makes we wonder if maybe our turtle's nervous running-back-and-forth when I first approached had been the behavior of a female looking for the base of a small tree, shrub or cactus beside which a pallet might be scooped out, and eggs laid? Maybe she was so attracted to my legs because they approximated tree trunks?
But is our tortoise really a female? All kinds of suggestions for "sexing your tortoise" can be found on the Internet, but the most useful seems to be that, in general, male tortoises tend to have longer, curvier tails, while female tails are shorter and stubbier. Our individual's tail looks unmistakably short and stubby to me.
Texas Tortoises are mostly vegetarian, and appear to crave more than anything the fruits of prickly pear cacti.
In Texas, Texas Tortoises are listed as threatened, and it is illegal to possess or collect them. However, on a federal level the species is not listed. However the Texas Tortoise is listed, the species is having a hard time because of habitat destruction ("clearing scrub"), road kill and collecting.
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A MIGRATING MONARCH BUTTERFLY BEING GORGEOUS
Just feast your eyes on the migrating Monarch butterfly at https://www.backyardnature.net/n/14/140921mo.jpg.
I know she's migrating because here in southwestern Texas we're south of the species' summer distribution area. A map showing the Monarch's summer distribution can be seen down the page at http://monarchwatch.org/blog/2014/03/monarch-butterfly-recovery-plan/.
That page also describes in detail the current catastrophe besetting Monarch populations.
In the picture, our Monarch is busy sipping nectar from spectacular flowers of the Dwarf Poinciana, various cultivars of which we've seen a lot of in Mexico. Our Dwarf Poinciana page is at https://www.backyardnature.net/yucatan/d-poinci.htm.
Here in southwestern Texas, during the summer we do have a frequently seen, closely related and fairly similar butterfly -- the same genus -- called the Queen, but that species is darker and smaller, not nearly as bright and striking as the Monarch. You can compare the Monarch pictured above with a Queen at https://www.backyardnature.net/n/a/queen.htm.
This year I've read so much about the collapse of the Monarch population that I wondered if I would ever see another one. This one heading south to Mexico despite all the dangers awaiting it, on a bright sunny morning there amidst all those Dwarf Poinciana blossoms was very heartening.
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REDCOAT SEED BUG
Approaching the Prairie False Willow profiled in the next section, a boldly patterned red and black bug was impossible to overlook suspended among the bush's white flowering heads. This bug was alert and nervous-acting. Sensing my nearness, he swung his body to behind a flowering head and kept still. Often when you want a bug to move to the front so you can photograph him you can place your hand on the other side of the bug and that'll scare him to move back around, but this one would have none of that and flew onto my arm. You can see him there at https://www.backyardnature.net/n/14/140921bg.jpg.
In that picture you can see that I'm not using the term bug sloppily. With mouthparts consisting of a straw-like proboscis used to suck juices from plant parts, plus the thickened bases of the front pair of wings, and the general shape, this is clearly a "real bug" of the True Bug Order, the Hemiptera. According to the Tree of Life Project, nowadays 41 insect orders are recognized (the number varies according to expert), so just knowing that a bug is a "true bug" goes a long way toward identifying who you have.
Volunteer identifier Bea in Ontario quickly pegged our pretty bug as the Redcoat Seed Bug, MELANOPLEURUS BELFRAGEI, distributed throughout Mexico and the hot, arid parts of the southwestern US, from California to Texas.
Nine brightly marked seed bug species, genus Melanopleurus, occur in the US, mainly in the arid Southwest, where normally they feed on members of the Composite Family, exactly as ours was doing. Their favorite parts of the composite plant to feed on are developing buds and seed heads. Seeds that have had their seed coats penetrated by a bug's proboscis may not develop properly or germinate.
The seed bugs' bright coloration, opposite to being camouflage, serves to warn potential predators such as birds and lizards that it's probably bad to eat them. In fact, if you pick up a seed bug you'll be reminded that they're somewhat related to "stink bugs." When both kinds of bugs are bothered they issue a sharp, pungent substance that probably repels predators.
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PRAIRIE FALSE WILLOW
In very thin soil at the rim of a roadcut through compacted, anciently deposited limestone gravel an interesting, knee-high member of the Composite or Daisy Family, the Asteraceae, showed up, as you can see at https://www.backyardnature.net/n/14/140921bc.jpg.
The small leaves were very short and narrow with single midveins leading to minute, sharp tips and arranged one per stem node (alternate) as shown at https://www.backyardnature.net/n/14/140921be.jpg.
The white flowering heads were occupied with only cylindrical "disc flowers," with no "ray flowers" looking like petals along the heads' margins, as seen at https://www.backyardnature.net/n/14/140921bd.jpg.
Flowering heads in the huge Composite Family are of are of three kinds: Those with only disc flowers; those with only ray flowers, and; those with both. So noticing that this plant's heads contain only disc flowers automatically disqualifies the vast majority of eligible Composite Family species our roadcut plant possibly could be.
In our part of the world when you see flowering heads like these you might think of the big group known variously as bonesets, thoroughworts or snakeroots, all previously regarded as members of the genus Eupatorium, though now that venerable genus has been split into numerous smaller ones. However, all the Eupatoriums I've ever known have been herbaceous. Our roadcut one is definitely a perennial with a woody base, as shown at https://www.backyardnature.net/n/14/140921bf.jpg.
So, that woody base is what caught my attention and set me scratching my head. In our area we do have another Composite Family group of plants with similar leaves, flowering heads and woody bases, the erosion-preventing Roosevelt Weeds, Baccharis neglecta, so common along the banks of the little Dry Frio River, but those are large, much branching shrubs ten feet high and taller (3m). You might enjoy seeing how similar the plants are in nearly every respect other than size and general form, on our Roosevelt Weed page at https://www.backyardnature.net/n/w/roosvelt.htm.
However, in the end our little roadcut bush did reveal itself as another of the same group as Roosevelt Weed, the genus Baccharis. It's BACCHARIS TEXANA, usually known as the Prairie False Willow, Prairie Baccharis or False Willow. In the US it's found naturally only in Texas, Oklahoma and New Mexico, but it extends as well into arid northeastern Mexico.
Like the Eupatoriums, Prairie False Willow in flower attracts pollinators such as butterflies and bees, and later its heads of dry, cypsela-type fruits provide fine gnawings for small seed-eating birds. It's also an excellent candidate for xeriscaping, and is sold in certain arid-country garden shops.
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GROUNDCHERRY
On a dry, rocky slope in limestone country a wildflower caught my eye because I was accustomed to seeing its kind of flowers and fruits on weeds in disturbed places, but this one apparently was a native adapted to our dry, highly calcareous (carbonate-rich) soil. You can see it, so spindly that it practically lies on the ground, at https://www.backyardnature.net/n/14/140921ph.jpg.
If you're familiar with our weeds you'll probably recognize that this is a kind of groundcherry because of its unusual and very distinctive flowers and fruits, as seen at https://www.backyardnature.net/n/14/140921pi.jpg.
Here are the two main features so characteristic of groundcherries -- genus Physalis of the Nightshade or Potato Family, the Solanaceae:
The fruits' bladdery walls are like paper and can be broken open easily to reveal the developing tomato-like fruit inside it, as shown at https://www.backyardnature.net/n/14/140921pk.jpg.
The pea-shaped item will enlarge and mature into something tasty. If you're familiar with the fruit called tomatillo of husk tomato -- like a small, firm, green tomato encased in a paper bladder and much used in Mexican cuisine -- you'll believe that tomatillos are very closely related to groundcherries. Tomatillos also belong to the genus Physalis.
Our plant's flower colors, though very unusual for the Nightshade or Potato Family, are typical of Physalis, which is yellow with a very dark center, as shown at https://www.backyardnature.net/n/14/140921pj.jpg.
In that picture, note the dense covering of fine, short hairs on the corolla. In fact, the whole plant is "downy" with such hairs, and that's a feature helping us identify our groundcherry to species level. It's the Smallflower Groundcherry, PHYSALIS CINERASCENS, in the US found mostly in Texas, Oklahoma and New Mexico but scattered here and there in surrounding states, and also throughout Mexico. Some experts recognize a species named Physalis mollis, supposed to be hairier than P. cinerascens, but nowadays most regard P. mollis as just a hairy form of P. cinerascens.
Actually, it's curious that groundcherries, genus Physalis, should have flowers and fruits so different from those of other members of the Nightshade or Potato Family, yet within the genus, typically flowers and fruits are remarkably similar from one species to another. Apparently, a ancient ancestor stumbled upon the unusual combination of features, and found it so effective that the ancestor engendered a host of "variations on the groundcherry themes," or "species of the genus Physalis."
Something else that's funny about groundcherry species is that normally they produce extensive underground rhizomes, so if you find a small group of them, they may all be shoots of the same plant. Yet, groundcherry flowers are strongly "xenogamous," which means that pollinators must transfer pollen grains from the stamen of one plant to the stigma of a different plant (not just a different shoot of the same plant) for seed-bearing fruit to be produced. Thus sometimes you find colonies of groundcherry plants which really are all the same plant, with none or few of the shoots producing fruits. That's because pollinators may go from shoot to shoot within the small group, not succeeding in transferring pollen between truly different plants. It seems strange that groundcherries would combine extensive rhizome production with "xenogamy."
Groundcherries are mostly pollinated by the insects known as solitary bees, and solitary bee species generally pollinate only one or a few closely related species, so that partly explains how rhizome-producing groundcherries could get away with xenogamy: Certain solitary bee species make a special effort to patronize just them.
This syndrome of fruits suspended in bladders, down-facing flowers with blackish centers, xenogamy, prolific rhizome formation and a heavy dependence on solitary bees for pollination is a complex, not fully understood, but complex and fascinating situation. What a pleasure it'd be to try to figure it all out. If you think you might like to try, a good place to begin is with Janet Sullivan's 1984 paper "Pollination Biology of Physalis viscosa var. cinerascens (Solanaceae)" appearing in the American Journal of Botany, Vol. 71, No 6.
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SNOWY INKCAP MUSHROOM
Several days ago we received a rare rain, and after months of no mushrooms at all, finally a few are appearing. For example, issuing from a dried-out pile of cow manure beside the road were the delicate, inch-tall ones (2.5cm) shown at https://www.backyardnature.net/n/14/140921cs.jpg.
Mushroom fanciers recognize these as members of that group of tiny, ephemeral mushrooms that appear overnight, then literally melt as the next day advances. Even these were about to liquefy, or "autodigest," as shown by the drooping rims seen in a side view at https://www.backyardnature.net/n/14/140921ct.jpg.
Inky caps as a group are easy to recognize, but finding out one's species name can be very hard. However, these cow-pad ones displayed a special feature on the cap, nicely shown at https://www.backyardnature.net/n/14/140921cu.jpg.
What's special is not the cap's neatly curled-up rims, for this is typical of many inky cap species, whose caps start out shaped like narrow thimbles pointing skyward, then as they mature flatten out, and finally curl upward, liquefying. What's special is the mealy-white particles scattered across the cap's center. That meal consists of "velar remains," or traces of the mushroom's velum or "veil." Veils, more precisely known as "universal veils," are temporary membranous tissues completely enshrouding immature, egg-like fruiting bodies of certain kinds of gilled mushrooms. The egg-like thing forms in the ground or organic litter, then the fruiting body we think of as the mushroom "hatches" from the "egg," breaking the "egg's" veil, and sometimes particles of the shattered veil stick to the mushroom's cap. That's happened here.
Referring to inky cap mushrooms in general, Michael Kuo, the expert at MushroomExpert.Com, writes that "Identification of these short-lived mushrooms (did I mention that they all look pretty much the same?) hinges on microscopic examination of various erudite features, and is an enterprise best left to folks who enjoy such endeavors."
He also points out that recent DNA studies reveal that the big group of mushrooms traditionally known as inky caps is composed of many species often not very closely related to one another. It's a matter of convergent evolution. That is, being a small, fragile mushroom with cap edges that curl up as the cap liquefies and spores are released into the wind -- is a very successful strategy. Therefore, various unrelated mushroom groups have evolved to employ the strategy, in the process coming to look and behave pretty much like other species taking up the same strategy.
(It's the same situation as with vultures. American vultures and European vultures are similar looking and with similar behaviors, yet American vultures have evolved from stork-like birds while European vultures are closer related to hawks and falcons. It's just that the carrion-eating niche is best exploited by birds looking and behaving the way vultures do, no matter who their ancestors were.)
Anyway, taking into account the above caveats about even trying to identify inky cap mushrooms to species level, I'm placing this entry under the name of the Snowy Inkcap, COPRINOPSIS NIVEA, because that's a common species found in our area, it grows on dung, and its cap is flecked with white "velar remains" exactly like this. Even if our mushrooms happen to be a different species, it's of value to experts to see what we have here in southwestern Texas.
This is such a small, delicate mushroom that it's not worth eating. It's been variously reported as toxic or at least "suspect," so it's not a good idea to nibble on it.
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PARASOL MUSHROOM
The day after our Snowy Inkcap appeared on the cow dung, a very similar inky cap appeared early in the morning, this time growing directly from hard-packed, gravely ground next to the road. You can see it at https://www.backyardnature.net/n/14/140921co.jpg.
Gingerly tilting the cap with my fingertip, the gills underneath showed themselves already beginning to melt into black goo, as seen at https://www.backyardnature.net/n/14/140921cp.jpg.
As with the Snowy Inkcap, this is obviously an inky cap, thus identifying it has to be considered an iffy business, However, with that golden "eye" in its cap's center and the neat way its papery cap is ruffled with all those little "pleats" radiating from the eye, it's so distinctive that I'm going to name it, because it looks just like a similar sized species that grows from the ground and is commonly found in our area, and that's the Parasol Mushroom, PARASOLA PLICATILIS.
And I'm sticking to this name despite the warning given by Michael Kuo at MushroomExpert.Com that "A gazillion little coprinoid mushrooms look like Parasola plicatilis on casual inspection, so a microscope is needed for successful identification of this widely distributed and common species."
But, really, if we're going to split taxa into such tiny segregates that no one uses those names but the experts, what's the point in regular people having the names of things, and without those names how are we going to discover what's good and beautiful about the organisms?
Anyway, Parasol Mushrooms are known to be saprobic, which means that they derive nourishment from nonliving or decaying organic matter. They grow alone or scattered in grassy areas, usually in direct sunlight, exactly as ours was doing, in summer and fall, and sometimes even in the winter in warmer areas. The species is widely distributed in North America and Europe.
And one other nice thing about the Parasol Mushroom is that it's just so unexpectedly dainty and elegant looking when you stumble across it at the gravely side of a road early in the morning with dew still on the grass that you just feel good seeing it, and being part of its world.
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FEATURED ESSAYS FROM THE PAST:
"On Living the Newsletter Life" from the June 5, 2011 Newsletter, at https://www.backyardnature.net/n/p/110605.htm
"On an Amapolo Flower" from the February 14, 2010 Newsletter, at https://www.backyardnature.net/n/p/100214.htm
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Best wishes to all Newsletter readers,
Jim
All previous Newsletters are archived at https://www.backyardnature.net/n/.
