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

September14, 2014

Nowadays late-summer and fall wildflowers are starting to flower, and among the most noticeable is the Lateflowering Boneset, Eupatorium serotinus, a shoulder-high member of the Composite or Daisy Family, with basketball-size heads of white, very fragrant compound flowers. The odor is like honey with a touch of freshly cut hay field in it. You poke your face down among the blossoms and you almost swoon from all the perfume. Of course butterflies and other insects are drawn to the flowers in large numbers. Among them at this season is a certain soldier beetle with a dark spot on each of its long, hard outer wings, or elytra (singular elytron). You can see a very satisfied looking soldier lounging amidst all the flowers' slender, tickling style arms and the heady perfume and sweet nectar at http://www.backyardnature.net/n/14/140914bt.jpg.

A view from the side of a nearby beetle is at http://www.backyardnature.net/n/14/140914bu.jpg.

Past experience shows that soldier beetles can be hard to identify, but volunteer identifier Bea in Ontario managed to cut down possibilities to the genus Chauliognathus, of which about 19 species are listed for North America. Of those, Bea thought it was one of two species, but wouldn't say which. It especially looked like Chauliognathus discus, but the pictures she found of that species lacked the dark spots on their elytra.

In reading about the species, however, a quote from K.M. Fender's "The Chauliognathini of America North of Mexico" turned up saying about Chauliognathus discus that the "Size of subapical elytral spots varies from immaculate to apical third of elytra being black." In other words, to be Chauliognathus discus, having spots is OK, and they can even have the whole end third of their outer wings black.

CHAULIOGNATHUS DISCUS is listed for Texas and New Mexico, but mostly is a Mexican beetle, occurring at least as far south as south-central Mexico. The species isn't known well enough to have its own common name, so it's just referred to as "Soldier Beetle," along with several other Chauliognathus species.

Just to enjoy the esthetic buzz of seeing "a variation on the soldier beetle theme," you might enjoy comparing our above picture with another soldier beetle found in our area, Chauliognathus scutellaris, at http://www.backyardnature.net/n/14/140517bt.jpg.

Soldier beetle adults typically are found on flowers, especially Composite Family members, where they mate and feed on pollen and nectar. The larvae range along the ground or among debris feeding mostly on eggs or larvae of other insects. Adults normally are seen in summer and early fall and the various species are mostly distributed in eastern North America.

It's said that the name soldier beetle derives from some of the species being red and black, like certain early military uniforms.


Here in late summer many plants are beginning to produce fruits and grains that birds love to eat. You can see a Lesser Goldfinch, common in the US's drier southwestern and coastal Pacific parts, at http://www.backyardnature.net/n/14/140914gf.jpg.

That one spent several minutes reaching into the chaff of the mature Common Sunflower flower-head below him, bringing out one cypsela-type, one-seeded fruit at a time, slowly grinding away at each one, swallowing, and then reaching for another. That's a pretty sight on a nice summer morning.

Adult male Lesser Goldfinches in our area have black backs, while the better known American Goldfinch, occurring coast to coast, displays only a black forehead but yellow nape, back and rump.


After being in southwestern Texas for nearly two years, finding wildflowers new to me is hard, and usually the new ones I do find are so small and inconspicuous that it's understandable why they were overlooked earlier. That's probably the case with the scrappy little plant almost unnoticeable amidst grass and dry leaves rooted in very thin, dry soil atop limestone shown at http://www.backyardnature.net/n/14/140914vb.jpg.

Most of the slender stems in the picture are actually flowering spikes whose flowers are so small that they don't show in the picture. In fact, the whole plant is smaller than other plants of its species seen on the Internet, apparently because of the very thin, dry soil it was growing in. Its undersized leaves are shown at http://www.backyardnature.net/n/14/140914vc.jpg.

In that picture you see two leaves -- the one on the left a bit bug-eaten. Three important field marks to notice are:

the leaves are two per stem node (opposite); the leaves are deeply lobed and the lobes are narrow leaves and stems are very hairy with white, stiff-looking, spreading hairs.

The opposite leaves already greatly narrow down the possibilities of the plant's identification and when you see the tiny flowers you pretty much know what group they belong to. Flowers with their very hairy calyxes, each arising above a conspicuous, leaf-like bract, can be seen at http://www.backyardnature.net/n/14/140914vd.jpg.

Besides all the hairs and the bracts, important field marks to note here are the corolla's lavender color and the fact that they're asymmetrical -- the corolla lobes are of different sizes and not equally distributed atop the corolla tube. A side view shows the curved tube's asymmetry better at http://www.backyardnature.net/n/14/140914ve.jpg.

When you see herbs like this with opposite leaves and asymmetrical corollas your first thought needs to be of two plant families: the Mint and the Vervain or Verbena Families. Once you're reminded of the Verbena Family you remember that vervains themselves ,genus Verbena, often look just like this, with small, dog-faced, lavender or purplish flowers arranged in long, slender flowering spikes.

And that's what we have, one of about 250 species of the genus Verbena, most species of which occur in the Americas and Europe.

Verbena species can be hard to distinguish, especially because the flowers are so similar. This is one plant group where vegetative features are especially important to note, which is a different situation from most cases.

Our spindly-looking little plant is the Gray Vervain, VERBENA CANESCENS, which can be separated from other species by is extreme hairiness, its especially long, slender flowering spikes, and its leaves bearing such slender lobes. The narrow leaf lobes are more noticeable on larger plants with better developed leaves. The Gray Vervain gets its name from its coating of hairs, which gives the entire plant a grayish cast. When such hairs produce this kind of grayness they are said to be canescent, which explains the species name, canescens.

In the US Gray Vervain is mainly a Texas plant, but it also turns up spottily in California, Nevada, Oklahoma and Alabama. In Mexico it occurs throughout most of the northern and central regions.


Lately we've been encountering interesting members of the Spurge or Euphorbia Family, the Euphorbiaceae. That's not too surprising, since the Spurge Family is big, holding about 7500 mostly tropical, mostly American species, and generally members of the family produce small, greenish, easy-to-overlook flowers. Last year I probably walked right past them, with my out for gaudier fare.

This week's knee-high, unspectacular but interesting attraction, growing in rocky soil on a slope in a limestone area, is shown at http://www.backyardnature.net/n/14/140914ar.jpg.

With one leaf per stem node (alternate arrangement) and the leaves with no lobes, no teeth on the margins, no hairiness -- at first glance this plant couldn't be more nondescript. However, notice the very slender items arising from the angles between the upper leaf bases and the stem -- the "upper leaf axils." Those are flowering, spike-like racemes, and clearly any flowers there are very small. However, notice on the left side of the picture a second, shorter stem leaning toward the image's border. At the very tip of that stem there's a pea-sized, roundish, greenish thing. A close-up shows what it is at http://www.backyardnature.net/n/14/140914at.jpg.

That's a three-lobed fruit, and the moment it came in view I knew we had another member of the Spurge Family. Flowers and fruits of most dicot wildflowers have their parts in 4s, 5s, or multiples thereof, but the big Spurge Family does things in 3s. Three-parted fruits are common among monocot-type wildflowers, such as lilies and orchids, but not dicot ones. A view of our three-lobed fruit from the front, showing a greenish, forked stigma arising at the top where the parts come together is shown at http://www.backyardnature.net/n/14/140914au.jpg.

Members of the Spurge Family -- "euphorbs," as botanists refer to them -- produce unisexual flowers, either at separate places on the same plant (monoecious), or on different plants (dioecious). Our plant is monoecious. Those slender items seen earlier at the top of the plant were racemes of male flowers from which most flowers had fallen after their pollen had been released. You can see the racemes with a few male flowers still attached at their tips at http://www.backyardnature.net/n/14/140914as.jpg.

A leaf with three major veins arising at its base and a male-flower raceme emerging from the leaf axis is at http://www.backyardnature.net/n/14/140914av.jpg.

When keying out the genus, these field marks are noted:

These and other features lead us to the genus Argythamnia, which in the old days was called a more memorable Ditaxis. Members of the genus are commonly known as silverbushes.

Four Argythamnia species occur in Texas, and this one separates from the others easily with its long, slender racemes of male flowers overtopping the leaves below them by a long shot. It's the Plateau Silverbush, sometimes also called Tall Wild-mercury; it's ARGYTHAMNIA SIMULANS. The "Plateau" in the first name alludes to the fact that in the whole world the plant occurs only in Texas, mostly in the south-central part of the state known as the Edwards Plateau. We're on the Pleateau's southern slope.

Since it's so uncommonly encountered, not much is known about the Plateau Silverbush. I'm tickled to provide what little information we have on it here.


My neighbor Phred keeps numerous pretty and interesting potted plants around his house. In the spring he buys them in town when small, re-pots them, keeps them watered, and now after months of growth they're spectacular. One such ornamental potted plant not seen much outside our hot zone is shown on his steps at http://www.backyardnature.net/n/14/140914sv.jpg.

Up close the purplish flowers are surprisingly hairy, the calyxes actually woolly, as shown at http://www.backyardnature.net/n/14/140914sw.jpg.

Notice that the leaves are deeply wrinkled, or "rugose," and that they occur two per stem node (opposite). Also, the flowers arise several together at separate points along the tall, slender, spike-like raceme's central stem, or rachis. Noticing these features, the gardener might be reminded of Garden Sage, whose leaves and flowering heads are just like this. You can compare Phred's potted plant with Garden Sage on our page at http://www.backyardnature.net/n/h/gardsage.htm.

Everything looks similar except the flowers, and they're very different. Phred's plant is by no means Garden Sage. However, the above picture also shows that the flowers display bilateral symmetry -- only one way to cut them lengthwise so that both sides show mirror images of the other -- and that's also like sage.

If you've been with me through several sage species you might remember that sages, which are members of the Mint Family genus Salvia, do something tricky and distinctive with their stamens. The stamens in flowers of the vast majority of plants consist of two bag-like, pollen-producing cells side by side, like two frankfurters side by side at the end of a stick. Salvia widely separates its two anther cells, putting a long, slender "connective" between them, so that the filament is a little like a Y, each long arm of the Y bearing one anther cell. One cell on one end of the connective produces pollen normally but the other cell at the connective's opposite end is either rudimentary or completely lacking. The connective where the second cell may or may not exist then functions as a kind of lever that pollinators push against as they enter the corolla tube searching for pollen or nectar. The design is such that by pushing the lever, the anther cell full of pollen is swiveled down so that it daubs pollen on the pollinator's rear end.

So, do the flowers on Phred's potted plant display such amazing stamens? A broken-open flower shows us at http://www.backyardnature.net/n/14/140914sx.jpg.

That picture, showing two stamens, is a little hard to interpret, but at least you can see that the filament is branched in a strange way, and that the anther cells appear to be single ones well separated from one another. In other words, we do have a sage, genus Salvia.

Keying out this species goes fast because very few sages produce such densely hairy flowers. Its the Mexican Bush Sage, SALVIA LEUCANTHA, a native of Mexico, but now planted widely in warmer areas. In the US it's suggested for areas as far north as USDA Hardiness Zone 8A, which includes the US Gulf Coastal Plain, California, the Pacific Coast and southern Arizona. Phred's plant look a bit spindly, but numerous plants in a garden produce spectacular masses of purple flowering spikes, which are much visited by pollinators. Different cultivars exist, with corollas ranging from white to purple.

In Mexico, wild plants of the species are used medicinally for lung ailments.


In the parking lot of Uvalde's fine El Progreso Memorial Library a certain much-branched, head-high bush struck me as both unfamiliar and familiar. It was unfamiliar at a distance where all that was apparent was its density and large number of fairly good sized yellow flowers, as seen at http://www.backyardnature.net/n/14/140914tc.jpg.

Up close, however, its pinnately compound leaves with conspicuously toothed leaflet margins, and its basketball-size panicles of large, trumpet-shaped, yellow blossoms, all seemed very familiar, as seen at http://www.backyardnature.net/n/14/140914td.jpg.

A shot of the pinnately compound leaf is at http://www.backyardnature.net/n/14/140914te.jpg.

A close-up of two flowers is at http://www.backyardnature.net/n/14/140914tf.jpg.

In much of Mexico as well as southern and western Texas and southern Arizona and New Mexico -- in fact throughout most of tropical America as far south as Argentina -- there's a common small tree or bush looking exactly like this, except that it's a regular small tree with one or a few regular trunks, instead of consisting of very many short, slender stems arising from the bush's base.

What we have here in the library parking lot is a cultivar of the wild plant I'm remembering. Because the species is so pretty and in some places so common it goes by several English names, including Yellow Bells, Yellow Trumpetbush, Yellow Trumpet-flower and Yellow Elder. In Texas often the Spanish name is used, Esperanza.

Yellow Bells is TECOMA STANS, a member of the mostly tropical Bignonia or Trumpet Creeper Family, the Bignoniaceae. This family is especially rich in woody vines, or lianas, and usually but not always its leaves are compound and occur two to the stem node -- they're "opposite." Fruits are dry pods, often long and woody, that split on both sides to release many flattened seeds which usually bear papery "wings" helping with wind dispersal.

In the wild, Yellow Bells is partial to rocky hillsides and foothills, but also often grows in disturbed sites such as roadsides. It's also frequently cultivated for its prettiness, and in warmer areas it may escape and sometimes becomes a troublesome "weed tree."

Robert Vines in his book Trees, Shrubs & Woody Vines of the Southwest writes that Yellow Bells was long used by indigenous folks of the US Southwest and Mexico for bowmaking, bee fodder and medicines.

On the Internet many pages state that Yellow Bells is poisonous, and though bees may collect the plant's nectar and make honey, the honey is poisonous. However, these pages are mostly at garden forums and small, one-person web sites, and often the wording is the same from page to page, suggesting that the information has been copied and recopied. In fact, at the usual academic sites dealing with toxic plants, I can't find any mention of Yellow Bells' toxicity, or that honey produced from its nectar is bad.

Van Dersal in a 1942 piece writes that in Mexico the flowers yield honey, the roots a type of beer, and medicinally the plant is regarded as having diuretic, antisyphilitic, vermifuge and anti-diabetic properties -- though later studies disproved the anti-diabetic part.

I rather suspect the reports of Yellow Bells' "toxic honey," and hold with the opinion of the great L.H. Bailey, author of my precious Manual of Culivated Plants, that "The value of this shrub ... cannot be overestimated."


Despite the lateness of the season, branches of American Sycamores along the little Dry Frio River still have small, silvery leaves unfolding at their branch tips, as shown at http://www.backyardnature.net/n/14/140914sz.jpg.

The immature leaves are heavily invested with a whitish, mealy kind of hairiness. Remembering that we have microscopes at Juniper House, I snipped off a freshly emerged leaf about the size of my thumbnail, put it beneath the dissecting scope, and saw what's shown at http://www.backyardnature.net/n/14/140914sy.jpg.

That's the bottom and side of a recently emerged leaf. Looking at the hairs flat-on, they looked like the kind of hair called "stellate," or "star-like," where several sharp hairs originate in various directions from a common base, like half of a sea urchin on the blade surface. However, hairs at the leaf's margins, seen from their side, reveal that they're actually "plumose," or "feather-like," consisting of a slender stem bearing numerous side branches.

Such hairs certainly do protect the developing leaf's delicate tissue from water evaporation, intense sunlight, temperature extremes and physical damage. Maybe a caterpillar would think twice about chewing into all that fluffy stuff, too.



"On Turning Sixty" from the December 3, 2007 Newsletter, at http://www.backyardnature.net/n/p/071203.htm

"On the Beauty of Convergent Evolution" from the April 13, 2003 Newsletter, at http://www.backyardnature.net/n/p/030413.htm


Best wishes to all Newsletter readers,


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