Issued from the valley of the Dry Frio River on the
southern slope of the Edwards Plateau, northern
Uvalde County, southwestern Texas, USA

October 21, 2012

Each evening just as the day loses its last light, in a certain spot along the wooded banks of the little Dry Frio River near the cabin the turkeys go to roost. It's a pretty thing to watch, seeing the big birds a bit clumsily but ever so vigilantly ascend the trees limb by limb, constantly craning their necks first in this direction, then that. They display a primitive alertness and excitement such as our human ancestors must have felt with the approach of a night of darkness. You can get a hint of what I'm talking about as part of a flock climbs into a big, riverside Pecan tree at http://www.backyardnature.net/n/12/121021tu.jpg.

I read that in this area Wild Turkeys establish different summer and winter roosts. The winter roosts, typically located along streams and rivers or in large valleys, host large numbers of birds. But then as spring nesting season approaches the birds spread into the landscape and establish smaller, more private roosts.

Of course ground-loving turkeys roost in trees because they're safer from their predators there, and can see their predators better from above. If they need to fly, they're already in the air with a head start.

Property owners wanting Wild Turkeys to feel at home on their land should provide appropriate large trees for the turkeys to roost in. The roost is profoundly important to a turkey.


In mid morning, two stone throws from the little Dry Frio River, a dark dragonfly with a wingspan of four inches (10cm) perched on a twig level with our eyes. Her cellophane-like hindwings were so tattered and she was so quiet and disinterested in our presence that she gave the impression of being an old, battle-worn individual, one just wanting to be left alone. You can see her at http://www.backyardnature.net/n/12/121021df.jpg.

With such conspicuous black markings at the wing bases and the white spots on the abdomen, I figured this would be an easy species to identify in my "Dragonflies through Binoculars" field guide, and that was true. She was a Black Saddlebags, TRAMEA LACERATA. Besides the larger size and slightly different black markings on the wing, females and juveniles display yellow-brown faces, as seen at http://www.backyardnature.net/n/12/121021dg.jpg.

There's a whole group of dragonflies known as saddlebags -- in North America seven species in the genus Tramea. They're called saddlebags because seen at a distance the black spots at their wing bases look like objects being carried at the dragonflies' sides. None of America's other saddlebag species has ours white abdominal spots.

This is a widely distributed species, from the Yucatan, Bermuda and the Bahamas to Baja California north throughout all but the US north-central states, plus it's barely in southern Canada, and on Hawaii.


A very fuzzy caterpillar wiggled fast across the driveway and climbed up a stepladder on which potted plants were arranged. He's shown about to enter one of the pots at http://www.backyardnature.net/n/12/121021ct.jpg.

I wasn't sure he should be on my potted plant so I picked him off, causing him to curl into a defensive ball so that all his soft belly spots were protected by spiky hairs, as shown at http://www.backyardnature.net/n/12/121021cu.jpg.

In eastern North America during the fall similar caterpillars often are noticed crossing roads and generally wandering about. Every kid knows them as Woollyworms or Woollybears. They're caterpillars of the Isabella Tiger Moth, and folklore has it that you can predict how harsh the upcoming winter will be by how dark the Woollyworm is -- the darker the Woollyworm, the colder the coming winter. However, Woolyworms exhibit black and orangish bands while our stepladder caterpillar -- very similar in all other features -- displayed no bands. So off the picture went to volunteer identifier Bea in Ontario, who recognized it immediately, since it also occurs up there.

It's the larva of the Salt Marsh Moth, also known as the Acrea Moth, ESTIGMENE ACREA. The caterpillars are sometimes known as Salt Marsh Caterpillars. Salt Marsh Caterpillars are indeed in the same moth family as Woollyworms, the Arctiidae, but they're in entirely different genera, so they're not as closely related as I'd figured they were.

Salt Marsh Caterpillars, despite their English name, occur in many habitats other than salt marshes, and in places far from salt marshes. They're found all across the US, from southern Canada south through Mexico into Central America. They eat a wide variety of foods, including cabbage, cotton, leaves of walnut and apple trees, tobacco, pea vines, potato plants, corn and clover, and in some places they damage crops, especially the US Southwest. So, I'm glad I removed this one from my potted plant and I hope it found a nice clover someplace to eat on instead.

Salt Marsh Caterpillars defoliate the plants they feed on. Young larvae feed gregariously and "skeletonize" leaves, eating the blades but leaving the midrib and main veins. Older larvae are solitary and eat large holes in leaves. Older larvae may disperse long distances looking for food, sometimes moving in large numbers.


One of the most eye-catching wildflowers blooming nowadays is shown with its flowers, fruiting heads and wiry-looking leaves at http://www.backyardnature.net/n/12/121021rb.jpg .

A closer look at that bodacious blossom is provided at http://www.backyardnature.net/n/12/121021rc.jpg.

Those yellow-margined, reddish-brown, petal-like ray flowers are enough to cause you to stop and admire, but what's unusual is that tall, cylindrical item in the flower-head's center. Here we're dealing with a member of the Composite, or Sunflower Family, so the bumps on the cylindrical item surrounded by yellow-fringed ray flowers are disk flowers. This wildflower was already flowering when I arrived here in late August, so some heads are mature now, bearing only clusters of achene-type fruits. You can see such a head with one side stripped of achenes -- maybe by a feeding bird -- at http://www.backyardnature.net/n/12/121021re.jpg.

The plant's pinnate leaves with very slender, hairy, gland-dotted lobes are shown at http://www.backyardnature.net/n/12/121021rd.jpg.

This spectacular wildflower often is called the Redspike Mexican Hat, also Upright Prairie Coneflower, or just Mexican Hat. It's RATIBIDA COLUMNIFERA, widely distributed in North America but mostly in the central prairie states and provinces from Canada deep into arid northern Mexico. It's mainly a prairie wildflower, but as a species it's adaptable enough to occur along roadsides and in other disturbed, fairly weedy sites. Though around here I've seen only plants with mostly reddish-brown ray flowers, blossoms on plants in other areas may have much more yellow on them, or be entirely yellow.

Not only is Redspike Mexican Hat a beautiful plant, but also it's easily grown in average, dry to medium, well-drained soils in full sun, so it's a favorite in wildflower gardens. It can be grown from seeds, though the plant requires two years to bloom.

Indigenous Americans are known to have made pleasant-tasting teas from Mexican Hat's leaves and flowers. Medicinally the plant's leaves and stems are said to relieve pain. The tea has been used for headaches, stomach aches and fevers, as well as for several other pains and miseries.


Though its individual pale to dark pink flowering heads aren't particularly spectacular, averaging only about 7/16ths-inch across (1cm), nowadays a certain wildflower is so abundant in certain spots and producing so many flowers that you can't avoid noticing them. A cluster of one plant's flowering heads, looking like miniature Carnations, is shown at http://www.backyardnature.net/n/12/121021pf.jpg.

A close-up of one of the heads is at http://www.backyardnature.net/n/12/121021pe.jpg.

That picture shows that the plant is a member of the Composite or Sunflower Family, but that the heads lack petal-like ray flowers around their perimeters, so that the heads consist only of deeply lobed disk flowers. In most composite flowers, disk flowers are found only in the head's "eye."

A close-up showing a broken-apart head in which the individual flowers' maturing achene-type fruits are shown packed closely together is shown at http://www.backyardnature.net/n/12/121021pg.jpg.

In that picture it's worth looking at the tops of each achene, to see pappi a bit different from those we usually encounter. Most often when we pay attention to an achene's pappus it's composed of a ring of slender, white hairs surrounding the cylindrical base of the corolla. Such pappi will mature into "parachutes" atop the achene fruits -- such as the white fuzz atop a Dandelion's achene. That fuzz helps the achene disseminate on the wind. This wildflower's pappus, very different from that, consists of a ring of papery, hairy scales. In wildflower identification, pappus type is very important. Seeing these scales, we can automatically omit many other Composite Family members with heads consisting only of pink, deeply lobed disk flowers, but with different kinds of pappi.

Another good field mark for this species is that its stems are heavily invested with glandular hairs. A microscopic shot of a peduncle right below a flower head shows dark, flat-topped glands atop stubby hairs mingled with sharply pointed, segmented hairs, or trichomes, bent at their bases so that they point upward, as seen at http://www.backyardnature.net/n/12/121021ph.jpg.

The most common English name for this attractive and locally abundant wildflower is Small Palafoxia. It's PALAFOXIA CALLOSA, distributed mostly on soils derived from limestone throughout most of Texas, up into Arkansas and Missouri, and south into northern Mexico. Around here Small Palafoxia is specially abundant on gravel bars of the little Dry Frio River.

During all my years of wildflowering this is the first time I've run across the genus Palafoxia, despite the genus embracing twelve species, of which ten occur in the US. Palafoxias in general are thought of as drought-tolerant, annual herbs growing on sandy plains, dunes, deserts (Mojave and Sonoran Deserts) rangeland and, in our case, limestone soils. Bees, butterflies and birds are attracted to them, and certain butterfly caterpillars feed on them. The genus is named in honor of General José Palafox, 1776–1847, Duke of Zaragoza, Spain, who fought against Napoleon's armies.


If you wade upstream for about ten minutes in the little Dry Frio River behind the cabin you arrive at the pretty spot shown at http://www.backyardnature.net/n/12/121021mu.jpg.

What's that big, pretty clumpgrass along the banks? Nowadays its slender, diffuse, pale, panicle-type inflorescences glow brightly in the sunlight, accenting the Dry Frio's borders very prettily. You can get a better idea of the grass's dimensions in a picture also featuring my Estonian lady-friend Malle at http://www.backyardnature.net/n/12/121021mv.jpg.

A close-up of the flowers with their purplish anthers dangling out is at http://www.backyardnature.net/n/12/121021mw.jpg.

In that picture you see that each 1/8th-inch-long (3mm) floral unit, or spikelet, has white glumes at the base, and contains one or two florets with white lemmas and paleas, all about the same length. The lemmas bear slender, sharp, needlelike awns at their tips. These special grass-anatomy terms are covered at http://www.backyardnature.net/fl_grass.htm.

This wonderful grass is variously called Big Muhly, Blue Muhly Grass, Lindheimer Muhly and other names. It's MUHLENBERGIA LINDHEIMERI, native to arid northern Mexico, plus in the US it's limited to southwestern Texas's Edwards Plateau area.

It's a shame that such a beautiful grass doesn't occur in more of North America. However, horticulturalists have recognized its esthetic value so sometimes you can find it in garden centers in USDA Zones 7-11 -- basically the US Deep South and the West Coast. Named cultivars have even been developed, such as the 'Garden Leader Muhly Blue,' described at the About.com Gardening site as "a fairly well behaved clump former that only grows about 2' high, but makes a big splash with its bushy 5' flower spikes. The foliage is a subtle bluish gray that blends well with other plants. The blue gives way to a purplish color in fall, then ages to a shiny gray and persists all winter."

I see a few smaller plants scattered here and there on rocky slopes but around here Big Muhly is a streamside specialist. Wander just a few feet from the Dry Frio's banks and there's no Big Muhly. Big Muhly's ample seed crop feeds many birds and rodents, but the main ecological service the species provides here is provided by it dense clumps of slender leaves, which protect the river's low, vertical banks from erosion.


Most of the little Dry Frio River behind the cabin is only ankle deep and the submerged limestone pebbles or bedrock are coated with a pale kind of loose, lime-rich mud that's very slippery. However, here and there waist-deep pools of clear water occur and sometimes interesting aquatic plants and animals take up residence in these pools. That's the case at a certain swimming hole where a frayed, yellow swinging-rope dangles from the limb of an overhanging Sycamore. At the edge of this tranquil pool there's a picturesque colony of submerged, leg-long, three-finger-wide aquatic plants with their wormlike bodies slowly undulating in the weak current and their tips pointed downstream, as you can see at http://www.backyardnature.net/n/12/121021my.jpg.

Some of the underwater stems approach the bank close enough for you to see their whorls of green, feathery leaves arising from thick, succulent, reddish stems, as shown at http://www.backyardnature.net/n/12/121021mz.jpg.

If you pluck at the stem, it fragments easily. You can see a stem fragment with detached leaves in my hand at http://www.backyardnature.net/n/12/121021mx.jpg.

In this year's May 27 Newsletter we profiled a similar aquatic choking a ditch in bottomland Mississippi. That was Parrotfeather, Myriophyllum aquaticum, native to the Amazon River Basin but now a serious aquatic weed in much of the world with warmer weather. You can see how it's similar, but different, from what we have here at http://www.backyardnature.net/n/h/parrot-f.htm.

Our Texas plant is a member of the same genus as Parrotfeather, but it's a different species, and it's native to the US Southeast, from Florida to Texas. It's MYRIOPHYLLUM HETEROPHYLLUM, variously known as the Variable-leaf Watermilfoil, Two-leaved Watermilfoil, also as Parrotfeather, and by other names as well. It's a member of the Watermilfoil Family, the Haloragaceae.

The watermilfoils, or genus Myriophyllum, embrace about 69 species of freshwater aquatic plants. Six or so species can be found in Texas, and in some lakes, streams and irrigation canals different species are causing problems by choking waterways. Three species in North America are considered serious invasives. Our Brazilian Parrotfeather in Mississippi was one of them, and our peaceful-looking Dry Frio watermilfoil, despite being native here, is another.

The problem is that in recent years Variable-leaf Watermilfoil has extended its distribution area northward, maybe helped along by global warming. A website based in New England, where it wasn't noticed until 1932, says that it can "... completely congest waterways and crowd out other species of aquatic plants. It also hinders recreational activities such as boating, swimming and fishing. The dense growth that forms also provides breeding areas for mosquitoes and degrades the quality of the water for fish and other aquatic wildlife."

State governments differ in their opinions about Variable-leaf Watermilfoil. In Ohio and Pennsylvania it's listed as Endangered, but in Vermont it's listed as a Class A noxious weed, and in Massachusetts and Connecticut it's banned.

However, down at the swimming hole below the cabin, the Bluegill fish seem to love the environment the plant creates, hiding among its slowly undulating stems, nibbling at snails and other tiny critters on its stems and leaves.


Immediately after gaining access to a microscope with a camera attachment, I hiked down to the little Dry Frio River behind the cabin, scooped some water with a little mud in it into a cup, brought it home and looked at it. It was like going to a zoo with lots of moving things I couldn't identify, but one that I could. You can see the thing I knew at http://www.backyardnature.net/n/12/121021sp.jpg.

That's the filamentous green alga known as Spirogyra. No algal genus is easier to identify microscopically than Spirogyra, because of the unique and beautiful helical or spiral arrangement of the chloroplasts. In the above picture each segment is a cell connected end-to-end with other cells. The black blob at the top, right is just debris. Again, the spiraling things are chloroplasts, which are cell bodies, or organelles, containing chlorophyll used for photosynthesis. Spiraling chloroplasts are very different from the spiraling DNA found in cell nuclei and visible only with very much higher magnification. In other algal cells chloroplasts may be scattered randomly or in other configurations. Many algal cells contain only one chloroplast.

Interestingly, chloroplasts have their own DNA. It's thought that that's because early during the evolution of Life on Earth a free-living cell such as an algal cell took into its body a similarly free-living cyanobacteria -- the bigger cell "ate" the smaller cyanobacteria cell -- but instead of the cyanobacteria being absorbed into the larger cell's body, the cyanobacteria survived and began sharing its photosynthesized products with its new "host cell," and ever since then the offspring of that first ingested cyanobacteria have lived as chloroplasts in algal and plant cells.

Anyway, what's in the photograph is an alga of the genus Spirogyra, of which more than 400 species have been recognized around the world. Species are identified largely on their conjugation pattern (sexual practices) and reproductive stages. I don't know what species is shown in the photograph but it looks like SPIROGYRA COMMUNIS, an exceptionally widespread (worldwide), common species.

Our little strand of Spirogyra was so small that I didn't see it when I placed a drop of water on the slide. In nature Spirogyra presents itself as very fine, bright, dark-green filaments moving gently with the water currents in the water. Masses of Spirogyra feel slimy, the slime deterring creatures which otherwise might attach themselves to it.

I had expected most pages on the Internet dealing with Spirogyra to be praising its beauty and ecological importance, but I should have guessed: Most deal with how to get rid of Spirogyra -- pages sponsored by dredging contractors, pond liner companies, fish stocking companies, etc. Spirogyra doesn't cause problems in low, natural concentrations but water with a heavy nutrient load, such as streams with fertilizer runoff or lots of phosphorus from urban-based detergents, can "bloom," clogging water filters and turning streams or aquaria into green soup.

You can see a variety of Spirogyra species at http://protist.i.hosei.ac.jp/pdb/Images/Chlorophyta/Spirogyra/.


In this arid country both mushrooms and ferns are uncommon, so when you spot one it's worth taking notice. This week as I waded upstream in the ankle-deep, very slippery-bottomed little Dry Frio River behind the cabin I found a fern. It grew in the dark shade of overhanging shrubs on a little limestone ledge at the water's edge about a yard (meter) above the water. The combination of dry limestone outcrop and high humidity just inches above the river's surface was just what this fern needed. You can see its dangling, three-times-pinnate fronds at http://www.backyardnature.net/n/12/121021ad.jpg.

A close-up of individual leaflets, or pinnae, is at http://www.backyardnature.net/n/12/121021ae.jpg.

With the frond divided like that into so many individual segments, and the stem slender, brittle and very dark, you might recognize this as a kind of maidenhair fern -- as a member of the genus Adiantum. But about 200 maidenhair species are recognized, so which is this one?

In most of eastern North America, except for the US Deep South, the common maidenhair species is the Northern Maidenhair, which we profiled just a couple of months ago in Mississippi, shown at http://www.backyardnature.net/n/x/adiantum.htm.

Our Texas maidenhair's pinnae are not organized on long stems, or rachillas, like that species', but rather cascade like random confetti tumbling from the shadows. Our Texas species is the Venus's-Hair Fern, sometimes also called the Southern Maidenhair. It's ADIANTUM CAPILLUS-VENERIS, a species that craves moist limestone cliffs, banks, and ledges along streams and rivers, so we found it exactly in its favorite kind of haunt. Venus's-Hair Ferns are distributed from Amazonia in South America up through Central America and Mexico into the southern half of the US, from coast to coast, plus it's found in Eurasia and Africa.

No rigorous scientific studies support use of the Venus's-Hair Fern for medicinal purposes, but traditionally many cultures have regarded "teas" or syrups made from its leaves and roots as strong medicine. Many herbal stores -- which often market it as Avenca, a name from Brazil -- sell it for respiratory disorders, hair loss, gallstones, and to regulate menstruation. Certain Amazon tribes use it for the same reasons, and other societies have employed it to reduce cholesterol and blood pressure, lower blood sugar, to detoxify the body, and for other cures.



"On the Pleasures of Simple Tastes," from the November 10, 2002 Newsletter, at http://www.backyardnature.net/n/p/021110.htm.

"Colors of Simplicity" from the October 4, 2009 Newsletter, at http://www.backyardnature.net/n/p/091004.htm.


Best wishes to all Newsletter readers,


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