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

May 19, 2013

The mulberry trees are producing, which means that mulberry-eating birds create a colorful circus inside the trees. The most brightly colored bird, one who seems to stay inside the trees most of the daylight hours, is a male Summer Tanager, shown after flitting from a mulberry into the garden Chinaberry at http://www.backyardnature.net/n/13/130519tg.jpg.

Summer Tanagers are common here during the warm months, overwintering from the southern half of Mexico south through Central America into the northern quarter of South America. During recent years they've been one of my prime birdbath visitors during winters in the Yucatan.

But, here, nowadays you hear them all through the landscape, their easy going, rambling, sweet warble of 15-30 syllables somehow a harmonious uttering for our peaceful summer days. Sometimes they also erupt with a fast, low, down-to-business chicky-tucky-tuk call.

I read that their prime food consists of bees and wasps, but the ones behind the cabin, at least for a few days, simply have been gorging on mulberries.


When the neighbor's two boys on their oversized four-wheeler roared up to my backdoor carrying a gallon jar stuffed with grass I figured they'd caught another critter, and I was right. This time it was the green snake shown at http://www.backyardnature.net/n/13/130519gn.jpg.

The boys said the snake hadn't been stomped, beaten or run over, but it bore some bumps and kinks and moved awfully slowly to be a healthy snake, so I felt sorry for it from the beginning. You can see a close-up of the head, looking like it's been mashed into the ground sometime, at http://www.backyardnature.net/n/13/130519go.jpg.

I took the head picture because more than one species of green snake exists, and often it's the configuration of scales on the head that enable you to distinguish otherwise look-alike species. However, in this case the scales weren't needed, since there's only one green snake in southwestern Texas, the Rough Green Snake, OPHEODRYS AESTIVUS, distributed throughout the entire Southeastern US, as far north as southern New Jersey and eastern Kansas, and south into eastern Mexico. The Eastern and Western Smooth Green Snake species with which our snake might be confused occur much farther to the north, mostly in the northeastern US and adjacent Canada.

Rough Green Snakes are graceful, mild-tempered tree-dwellers that during the day move slowly through vegetation, often trees and bushes, searching for grasshoppers, crickets, caterpillars and spiders. You couldn't want a more peaceful and agreeable snake, but when I was a kid on the Kentucky farm we figured that any reptile that was green had to be poisonous and they didn't last long around our house. When green snakes die they turn blue or black, and in our mind that surprising metamorphosis only confirmed the diabolical nature of the peaceful little being.

In a 1923 issue of Journal of American Folklore, Frank Speck writes that certain indigenous Americans in the northern regions believed that gently biting along the body of a green snake would cure a toothache.


Behind the cabin the little Dry Frio River comes up to a vertical wall about 20 feet high and the upper part of that wall is composed of gravel embedded in marly mud that has solidified into rock -- apparently millions of years ago. The mud was so high in calcium carbonate that basically it hardened into a cement wall.. Such a wall wouldn't seem to be much of a place for a bush to grow from, but several do issue from cracks. You can see such a bush with its freshly emerged leaves on zigzagging branches at http://www.backyardnature.net/n/13/130519rh.jpg.

Just by looking at this bush you can see that it's tough and wiry. A close-up of its pale stems and surprisingly small leaves is at http://www.backyardnature.net/n/13/130519ri.jpg.

In arid areas like ours, whenever I encounter a particularly tough, maybe spiny, much-branched bush like this, the first plant family to come to mind is the Buckthorn Family, the Rhamnaceae, because that family produces lots of dryness-loving, smallish, scratchy-type bushes and small trees. Therefore, I wasn't much surprised when flowers on the above plant turned out to be unmistakably of the Buckthorn Family, as you can see at http://www.backyardnature.net/n/13/130519rj.jpg.

Notice how the five stamens with their globular, pollen-producing anthers rise opposite the five small petals. In the vast majority of blossoms, stamens alternate with the petals, not rise opposite them. Also, the stamen bases emerge from below the margins of a conspicuous, fleshy disc that in our picture is shiny with nectar it exudes to attract pollinators; it's a "nectariferous disc." The disc sits atop the ovary, which is semi-inferior.

This tough little bush goes by several common names, including Hog Plum, Texas Snakewood, Texas Colubrina, Purple Haw and Guajalote. It's COLUBRINA TEXENSIS, endemic mostly to arid northeastern Mexico and across the border into the southwestern quarter of Texas. I read that it forms dense thickets in which the zigzagging branches fairly lock onto one another. I could find no spines on our bush.

Hog Plum thickets make important wildlife cover. Gardeners appreciate the shrub's ability to survive extreme drought conditions. I'm looking forward to tasting its fruits, or "hog plums."


A common, native, knee-high wildflower now blossoming splendiferously in the grassy area around the cabin is the one with gorgeous, two-inch-broad (5cm) heads shown at http://www.backyardnature.net/n/13/130519ga.jpg.

A study of just a head in all its glory is shown at http://www.backyardnature.net/n/13/130519gb.jpg.

This is one of the most beautiful and best known of all North American wildflowers, and as such it's known by several common names, including Indian Blanket, Firewheel, Blanket Flower, Sundance and Gaillardia. A member of the Daisy or Composite Family, it's GAILLARDIA PULCHELLA, and judging by its frequency around the cabin wherever water has run off roofs or I've watered ornamental plants, if we'd had normal rainfall this spring the Dry Frio Valley floor would now be resplendent with them, but instead they're just here and there, but even still a riveting presence.

Three Gaillardia species are recorded from Uvalde County, and we had one of them last week, the humble little Pincushion Daisy, Gaillardia suavis, which in our area this season don't even bear ray flowers -- the "petals" radiating from the head's "eye." You might enjoy seeing how the gross appearance of two species in the same genus can be so different by reviewing the Pincushion Daisy at http://www.backyardnature.net/n/h/pincushn.htm.

With such distinctive flower heads as Indian Blanket produces you don't need special field marks to identify it. Still, it's fun to take note of one feature setting this species apart from other Gaillardia species found here. You can see that field mark at http://www.backyardnature.net/n/13/130519gc.jpg.

In that broken-open blossom, do you see the needle-like "setae" poking up from the pale, convex-shaped receptacle from which several disc flowers have been removed? The other two Gaillardia species found here lack such setae.

Traditionally a tea brewed of Indian Blanket roots has been used for gastroenteritis. The root also has been ground into powder, chewed, and applied to the skin for various disorders. Nursing mothers with sore nipples bathed the nipples in tea made from the plant, and sometimes the same tea was used for sore eyes. Indigenous Americans of the Kiowa nation considered the presence of Indian Blanket as good luck.

I'll bet that over the years a million cars traversing our region from northern and western states have pulled to the side of the road so that someone could jump out and uproot some Indian Blankets for planting in the garden back home. Of course the uprooted plants soon died, for Indian Blankets are annuals, only sometimes lasting through mild winters to flower into a second year.

Indian Blanket thrives best on sandy or calcareous soil, even in disturbed places, but mostly in grasslands or open places. It's native to most of arid northern Mexico and the US southern states from Arizona to North Carolina, north in the central area to South Dakota, and here and there farther north elsewhere.


Each morning I jog down the valley as the sun rises, and that's a kind of meditation I enjoy, my body on autopilot, deer out in the fields watching like statues, the light changing moment by moment, cloud colors like slow-motion kaleidoscopes. A pasture along the road was broken up a few weeks ago in preparation for sowing grass for cows to eat. So far no grass has been sown, maybe because of the lack of spring rain, but the field has produced a bounteous crop of wildflowers with exceedingly large, white blossoms that in the pre-dawn light glow as if a kind of mysterious radiance were within them. You can see what I mean in a picture taken in predawn light at http://www.backyardnature.net/n/13/130519po.jpg.

Up close you see that with such bodacious blossoms and profoundly spiny herbage they can't be anything other than prickly poppies. One with a flower about four inches across (10cm) is shown at http://www.backyardnature.net/n/13/130519pp.jpg.

In that picture the yellow "eye" is composed of about 120 stamens, which are the blossom's pollen-producing male parts. In the center of the bouquet of stamens there's a tiny orange object deserving close inspection, which is done at http://www.backyardnature.net/n/13/130519ps.jpg.

The yellow things are the stamens, with granular pollen adhering to the open anthers atop their slender filaments. The orange-and-white thing is the stigma, which is the pollen-receiving part of the female pistil, the place where pollen grains germinate. I've never seen such a two-colored, ornately structured stigma as this. What a thing it would be to be that yellow critter so beautifully camouflaged at the picture's upper left corner, working your way through the forest of stamens and coming upon this otherworldly stigma head nestled in the forest center.

Once the blossoms are pollinated, the petals fall off and the ovary, which is also very spiny, rapidly expands, forming the item shown at http://www.backyardnature.net/n/13/130519pq.jpg,

That'll become a capsular fruit, but right now it's just a maturing ovary not worrying too much about critters biting into it.

Prickly poppies are members of the Poppy Family, the Papaveraceae, but they're not "real poppies." Real poppies are members of the genus Papaver; Prickly poppies belong to the genus Argemone. Presently 32 Argemone species are recognized, of which 15 occur in North America, mostly in the southern and western states. So, which of the 15 do we have here?

Because I've seen prickly poppies with large, white flowers in much of arid Mexico and the western US, and because ours grow so profusely in plowed fields and along roads, I figured my jogging-road ones would turn out to be rank weeds found over a broad area. Happily, however, the taxonomic treatment of prickly poppies is finished in the Flora of North America, so I could identify our plants with certainty, and they turned out to be something special.

They're narrowly endemic Texas Prickly Poppies, ARGEMONE AURANTIACA, in the whole world occurring naturally only in a few counties in central and southwestern Texas. The Flora of North America describes their habitats as "Fields, pastures, hills; 150-500 m (transition zone between lowlands and plateau)." That's us exactly, and what an exciting discovery.

One important field mark separating the Texas Prickly Poppy from other Argemone species in the region is the fact that the stem is copiously prickly with close-together spines, plus at least the bottom of the plant's leaves bear substantial, sometimes branched spines on their veins, and between the veins there are smaller stiff hairs or spines, as shown at http://www.backyardnature.net/n/13/130519pt.jpg.

Of course "real poppies" are medicinal -- morphine being derived from opium, which is made from the milky latex of the Opium Poppy, Papaver somniferum. Texas Prickly Poppies also produce a milky latex, orange in color, as you can see exuding from veins of a broken leaf at http://www.backyardnature.net/n/13/130519pr.jpg.

Native American cultures historically used prickly poppy latex for a wide variety of medicinal purposes. For example, the Seri people of Sonora, Mexico made an infusion, or tea, from the entire plant of a species found in their area (Argemone mexicana) both to relieve kidney pain, to help expel a torn placenta, and in general to help cleanse the mother's body after giving birth. The Texas Prickly Poppy wasn't recognized science until 1958 -- until then it was considered a variation of other species -- so little ethnobotanical information has been attributed to it. It can be assumed, however, that indigenous people in our area, not worried about the plant's taxonomy, had a very high regard for the magical properties -- whether real or imagined -- of the plant's startlingly orange latex.


Behind the cabin this winter saucer-sized rosettes of ferny leaves kept their greenness and fuzziness all through our freezes, hails and long periods without rain. Not long ago leafy stems bolted up from the taproots beneath the rosettes, and this week, atop knee-high stems, pretty, flat-topped, corymb-type inflorescences appeared, as shown in a scenic view of my backyard at http://www.backyardnature.net/n/13/130519yw.jpg.

A close-up of the thrice pinnately compound, eminently soft, fuzzy and odoriferous leaves is at http://www.backyardnature.net/n/13/130519yz.jpg.

A corymb-type inflorescence is one that is short and broad, more or less flat-topped, and with no particular limitation on the number of flowers the corymb might eventually produce. In a corymb, outer flowers open before inner ones. You can see our plant's corymbs atop ferny-leafed stems at http://www.backyardnature.net/n/13/130519yx.jpg.

A close-up of a corymb section is shown at http://www.backyardnature.net/n/13/130519yy.jpg.

Seeing how individual tiny flowers are held in tight clusters subtended by green, scaly, urn-shaped "involucres," we know we have a member of the enormous Daisy or Composite Family here. However, most of this Newsletter's readers won't need to "do the botany" to already know that here we're dealing with one of the most common, weedy, and best known of roadside plants, the Yarrow, ACHILLEA MILLEFOLIUM.

Having seen Yarrow in weedy places all across North America and Mexico, and remembering how it looked so at home in natural meadows at high elevations in the Alps, I've always assumed that Yarrow was a Eurasian invasive weed. However, the Flora of North America describes it as a very variable species native to practically the entire Northern Hemisphere's Temperate Zone. Its variability has resulted in at least 58 published technical binomial names just for North American plants, but the Flora treats all the variations as just the same "polymorphic" species. The Flora also says that European forms introduced several times into the Americas resulted in hybridization and the formation of various levels of polyploidy.

If you've smelled Yarrow's pungent leaves you can imagine that many medicinal uses have been proposed for the plant. One web page claims that Yarrow stops bleeding, makes tissues contract and helps them to heal, is antiseptic, is anti-inflammatory, and slightly anesthetic. It's used for coughs and to relieve muscle spasms. It's a traditional "women’s herb," used to ease the pain of menstrual cramping. And Yarrow supposedly lowers blood pressure and slows one’s heartbeat.

Yarrow can be collected for medicinal uses right now while it's flowering, or before the flowers appear. I'm collecting some to dry from the laundry shed's rafters, beside the Rabbit Tobacco and Horehound already there.


In certain spots in the grassy area around the cabin, nowadays a certain small, low-growing, daisy-type wildflower is profusely blossoming with ¾-inch broad (2cm) flower heads with yellow "eyes" and white rays. You can see a small part of the resulting spectacle at http://www.backyardnature.net/n/13/130519dy.jpg.

A close-up of a flowering head shows that the eye's yellow disc flowers are stacked atop a little mound in the flower's center at http://www.backyardnature.net/n/13/130519dz.jpg.

Being a small, low-growing, daisy-type plant with a yellow eye and white rays must constitute an exceedingly good survival strategy because plenty of species have evolved to look and behave like this one. In other words, this species is so similar to others that it can be hard to figure out which one it is. Therefore, with this plant I really had to "do the botany."

First I looked at the involucre with its collection of bract-like phyllaries below the flower head, and saw what's shown at http://www.backyardnature.net/n/13/130519dx.jpg.

Nothing unusual here, just that the phyllaries are hairy, have thin, cellophane-like (scarious) margins, and are arranged in only three or so series. Hoping for some surprises, I broke open a head and found what's seen at http://www.backyardnature.net/n/13/130519dw.jpg.

No bract-like items, or paleae, separate the individual disc flowers, so that's a little interesting. Most flowers looking like this have tiny, slender, white hairs constituting the pappus atop the future fruit, or cypsela, but I could see nothing like that here. However, these details are so miniscule, and my hand lens seemed to show something unusual atop the cypsela, so I put some almost-mature cypsela beneath the dissecting scope and saw what's shown at http://www.backyardnature.net/n/13/130519dv.jpg.

So, here's something special. Atop the cypselae -- the dun-colored items entering the image at the bottom -- there are no slender hairs of the usual kind, but rather there's a hairy "crown." In the picture, greenish bases of disc flowers emerge from inside the crowns and continue upward and out of the picture to become yellow disc corollas.

Such cypsela crowns are not unique to this plant, but they are rare enough that knowing about them and keeping in mind the other features we've mentioned, you can figure out what genus you have. Happily, the Daisy Family is already online at the unfinished Flora of North America, and there our cabin-side plant "keyed out" to the genus Aphanostephus, a genus that in the whole world embraces only four species found almost exclusively in the southwestern US and northern Mexico. Aphanostephus species are known generally as Lazy Daisies, also Doze Daisies, apparently because they make little effort to rise far above the ground.

Our species is ASPHANOSTEPHUS RIDDELLII, the only perennial in the genus, ascertained by digging up a plant and seeing and feeling the hard, woody taproot. Asphanostephus riddellii also differs from other species by bearing slender, unlobed upper leaves, but larger lower leaves that typically are deeply lobed.

As you've seen, Lazy Daisies are pretty enough to be welcome in any lawn. Some sources sell the seeds just for that.


Along the entrance road the most handsome as well as the most despised wild plant is the one shown being visited by a Pipevine Swallowtail at http://www.backyardnature.net/n/13/130519cd.jpg.

A close-up of a head in full flower is at http://www.backyardnature.net/n/13/130519ce.jpg.

This is a member of the huge Daisy or Composite Family, a species that bears no flat, petal-like ray flowers, only cylindrical disc flowers that constitute the head's round "eye." The slender, threadlike items radiating above the spherical head's surface are style branches

Everyone recognizes this surpassingly spiny plant as a thistle. However, there are lots of thistles, since the word thistle is a very general one applied to species in fifteen or more genera. Most people think of any very spiny plant that's a member of the Daisy or Composite Family as a thistle.

In North America's arid central grasslands and scrublands we have several native thistle species that are abundantly spiny, having evolved with herds of grazing Bison in the neighborhood. With their pretty blossoms and special adaptations for the prairies, they are real wildflowers worthy of protection. Mainly these belong to the genus Cirsium, of which maybe 60 species occur in North America. Therefore, here, when you meet a thistle like the one in the photograph, a good first guess is that it's a Cirsium.

However, our Pipevine Swallowtail's thistle isn't a Cirsium. It's a member of the genus Carduus, which embraces about 90 species native to Europe, Asia and Africa. The word carduus is Latin for thistle. Our plant is CARDUUS NUTANS, known as the Nodding or Musk Thistle. And Nodding Thistles are famous as one of the worst weeds in North America. It's the spines that make the plant so undesirable because livestock can't eat the plant, or else injure their mouths trying, and Nodding Thistles can soon take over a pasture as cattle eat everything except them. Nodding Thistles are prodigious reproducers, too, a single large terminal head capable of releasing as many as 1200 parachuted, cypsela-type fruits into the wind. A single plant with several flowers may begat up to 120,000 fruits, which can be carried on the wind for miles. Seed can remain viable in the soil for over ten years.

There's been such concern over the Nodding Thistle invasion that efforts have been made to control it biologically. Two weevil species, the Thistlehead-feeding Weevil and the Rosette Weevil, were introduced in several western US states with some success in killing the thistles. The problem was that the introduced weevils attacked our native thistles as well, including some rare wildflower thistles.

The main botanical distinction between Nodding Thistles and our native thistles in the genus Cirsium is that the hairs forming the fuzz parachute atop the cypsela-type fruits are branched, or feather-like, instead of being simple and unbranched.

Also, notice how broad and backward turned are the bracts, or phyllaries, below the flower head. In our native thistles the bracts are similarly spine-tipped, but their green bodies usually are closely pressed against the head base so that they point upward, not backward as in our Nodding Thistle. Also, among our native thistles of the genus Cirsium the purple-flowered part of the flower head normally is much less expansive than with our Nodding Thistle. A Cirsium flower head is usually urn-shaped, with the purple flowers arranged atop the green, bract-covered involucre below them. You can see that the flowers in our Nodding Thistle overtop the involucre, practically hiding it.

One good thing about Nodding Thistles, though, is that if you put your nose right up to a flowering head, it smells good. Butterflies and other pollinators love the plant. Also, North America's Nodding Thistles don't survive well in habitats that are not highly disturbed.


Despite the temperature in Uvalde already breaking 100° this week (38°C), around the cabin most of the grass is still winter brown, the drought suppressing all but modest sprouting of green shoots. However, where water from a few small showers has dripped off roofs and where laundry water escapes onto the ground, there are spots of lush grass. Nowadays one common grass citizen in these spots already has produced its flowers and now is drying up, with its fruiting heads ready to distribute seeds, as shown at http://www.backyardnature.net/n/13/130519br.jpg.

An inflorescence displaying the grass's large, flattish spikelets on slender, curving pedicels is at http://www.backyardnature.net/n/13/130519bs.jpg.

The individual spikelets are handsome, even elegant, as shown at http://www.backyardnature.net/n/13/130519bt.jpg.

Notice that the bract-like "lemmas" of each of the spikelet's florets is tipped with a slender, needle-like "awn."

When a spikelet is mature, it dries pale dun color and its florets break from one another -- they disarticulate -- so that each floret falls to the ground carrying a grain inside it, and a short section of its disarticulated stem, or "rachilla." Such disarticulated florets are shown at http://www.backyardnature.net/n/13/130519bu.jpg.

In grass identification, often it's important to look where the blades attach to the cylindrical stem, to see if there are "ligules" present and, if so, what the ligules look like. You can see a silvery, cellophane-like, jagged-edged ligule at a blade base pulled away from the stem of our grass at http://www.backyardnature.net/n/13/130519bv.jpg.

With our grass, however, as soon as I saw how large and flattish the long-pediceled spikelets were, and that the lemmas were tipped with slender awns, I had a hunch what group of grasses, or genus, we had here, so looking for a ligule wasn't important. There's a large, commonly occurring genus (over 50 species listed for North America) producing big, flattish, long-pediceled spikelets just like the ones in our photo. To make sure you have a species of that large, commonly occurring genus you need to take a very close look at the awns. A close-up showing how our grass's awns attach to the tips of its florets' lemmas is shown at http://www.backyardnature.net/n/13/130519bw.jpg.

Can you see that the lemma tips are shallowly notched, and that the short awns arise from inside the notch?

That tiny feature -- lemmas with notched tips and the awn arising from inside the notch -- is the glorious field mark that announces that you have a member of that big, commonly occurring genus, which is Bromus. Species of Bromus are referred to collectively as brome-grasses. So, which of the 50 or so brome-grasses found in North America is this?

"Keying out" this species was fairly easy because it has some unusual features. First, maybe you noticed in the picture of the entire spikelet that each lemma bore a well defined ridge, or "keel," down its back. The lemmas of most Bromus species are more rounded-backed and lack such conspicuous keels. Second, notice that each lemma bears about four parallel "veins" on each side, so with two sides and keel, that's nine veins per lemma. The lemma keels of most Bromus species display fewer than nine veins. Finally, the vast majority of other Bromus species bear much longer awns. The shortness of this species' awns is really remarkable.

So, here we have a grass most commonly known as Rescuegrass. It's BROMUS CATHARTICUS, a native of South America but much introduced in North America and other continents as a forage crop. Nowadays Rescuegrass is firmly established in much of North America, particularly in the southern half of the United States, mostly on disturbed soils. In other words, it's an invasive weed, but one ranchers like to have because it makes good forage for livestock.



"Robins, Mozart and Me," from the April 24, 2011 Newsletter, at http://www.backyardnature.net/n/p/110424.htm.

"Robins Fall Silent," from the July 25, 2010 Newsletter, at http://www.backyardnature.net/n/p/100725.htm.


Best wishes to all Newsletter readers,


All previous Newsletters are archived at http://www.backyardnature.net/n/.

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