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

March 30, 2014

Last Monday I slid my mountain bike into the back of neighbor Phred's truck and we headed to Uvalde 35 miles to the south, and 781 feet (238m) lower in elevation, where I was let out, and began biking back north to Juniper House. Spring down there is far in advance of what it is at our higher and more drought-stricken elevation. In the scrub forest along US 83 as I pedaled north, the most spectacularly flowering plant was the yucca shown at http://www.backyardnature.net/n/14/140330yu.jpg.

Many yucca species produce their leaves in spiky tufts at ground level, so one good field mark for this species is that its leaves issue from a trunk, which would be easily visible if the lower dead leaves and brush were cleared away. Another good field mark is that the large panicle of flowers is nestled among upper leaves and not held well above the plant on a clearly visible stem, or peduncle. Also, the panicle itself is broad, almost spherical, instead of tall and slender. A closer look at how the stiff blades attach to the stem is at http://www.backyardnature.net/n/14/140330yw.jpg.

A look inside the flower showing six oddly shaped stamens is at http://www.backyardnature.net/n/14/140330yv.jpg.

Seven or so yucca species are to be looked for in Uvalde County. Part of the uncertainty as to how many species we have is that the experts are in disagreement as to whether ours with trunks and roundish flower clusters, like the one in our picture, are represented by two species or one. The online Flora of North America, which I normally accept as the last word on what's what, lumps the two species, so if we accept the Flora's philosophy, our picture shows YUCCA TRECULEANA, which goes by such common names as Spanish Dagger, Spanish Bayonet, Trecul Yucca, Palma Pita, and Palma de Datil.

However, other experts, such as possibly most Texas botanists, and those advising the Wildflower.Org website, recognize Yucca torrei, usually known as the Torrey's Yucca. Shinners & Mahler's Illustrated Flora of North Central Texas recognizes both species, but admits that they hybridize. Based on descriptions, drawings and photographs, I can't be sure which species is in our photo, so I'm sticking with the Flora of North America, and filing this page under, Yucca treculeana. The name Spanish Dagger is applied to several species, some of them not even yuccas, but around here thata seems to be what everyone calls our tall yuccas.

Yucca treculeana mostly occurs in arid northern Mexico, but it extends into the US in southern Arizona, southern New Mexico and southern Texas; the questionable Yucca torrei covers much of the same territory.

Whatever our plants' "true name," this is a spectacular species, one that when in bloom in an ocean of gray-brown, wintry scrub draws attention to itself like a candle in a dark room. Those big, white panicles seem to hover in the scrub, ghostlike, beautiful.


In the scrub forest north of Uvalde, flowering Spanish Daggers are the most spectacular presences, but a close second is one of several acacia species found in the area, which right now is flowering in gorgeous, bee-hummed bountifulness. Some flowery branches at the edge of the scrub reaching toward US 83 are shown at http://www.backyardnature.net/n/14/140330ac.jpg.

Up close you see that the flowers are tiny, but multitudes of them are crammed onto spikes, and the spikes themselves cluster tightly, as seen at http://www.backyardnature.net/n/14/140330ad.jpg.

A close-up of a few individual flowers at the tip of a spike shows that from the bowl formed of calyx and corolla, more than ten stamens with their slender, white filaments and tiny, yellow, spherical anthers arise from each flower, at http://www.backyardnature.net/n/14/140330ae.jpg.

Each leaf of this small tree is twice-pinnate, as shown at http://www.backyardnature.net/n/14/140330af.jpg.

That picture shows one leaf. Its first division produces two segments which are attached to their common petiole extending from the picture's upper, left corner. Then each of those two divisions is further divided into six individual leaflets, or pinnae.

When you see this combination of features -- numerous stamens arising from each flower, and twice-pinnate leaves -- probably you're dealing with an acacia. In he old days, acacias belonged to the genus Acacia, but in 2005 someone screwed up a good thing so that now most serious institutions place them in the genus Vachellia. However, older field guides and most experts in Texas seem to continue using Acacia, so you're likely to find our magnificent little tree designated either as Acacia rigidula, or VACHELLIA RIGIDULA. Commonly it goes by the names Blackbush, Blackbush Acacia, Catclaw, Chaparro Prieto, Gavia and other names.

Ranchers in this area are likely to grub Blackbush from their land because grass for cattle could grow where it grows, and because it's been noticed that livestock grazing on Blackbush leaves in the fall sometimes show erratic behavior, such as "limber leg," where the animals stumble around. Noting this, researchers at Texas A & M University analyzed Blackbush and found it to contain toxic substances such as amphetamines. Amphetamines often are used by humans as weight-control supplements, so a whole new industry was born. If you Google "Acacia rigidula," the top of the resulting page will feature bottles of various herbal medicines for sale, all saying they contain Acacia rigidula. The pills not only are sold for for weight loss, but also to boost energy and stabilize moods.

Blackbush occupies disturbed sites such as fencerows, as well as rocky slopes and bluffs, and along arroyos mostly in arid northeastern Mexico, but extending into the US in southern Texas. It's common on the flat, Coastal Plain around Uvalde, but I've not seen it here on the limy soils of the southern slope of the Edwards Plateau.


Spring flowers are still very sparse in our part of the upper Dry Frio Valley, but down below, just north of Uvalde where large fields of Mesquite/ Acacia scrub have been cleared for irrigated agriculture, there are large, fallow fields mantled with prodigious numbers of flowering plants, as you can see at http://www.backyardnature.net/n/14/140330bv.jpg.

A single knee-high, somewhat scraggly plant is shown next to a fence at http://www.backyardnature.net/n/14/140330br.jpg.

A stem-tip cluster of blossoms is shown at http://www.backyardnature.net/n/14/140330bs.jpg.

In that picture notice that immediately below the opened, fully intact blossoms at the cluster's top, flowers that blossomed earlier are losing their sepals, petals and stamens, and that at the picture's extreme lower, left corner there's a naked ovary, the future fruit, from which all sepals, petals and stamens have been shed. On farther down the raceme the ovaries are from older and older flowers, so the lower you go the more mature and larger the ovaries are, until it is better to refer to them as immature or almost mature fruits. Notice that the maturing ovaries are held close to the main flowering stem, instead of spreading away from it, for that's a good field mark for this group of plants.

A single flower is highlighted at http://www.backyardnature.net/n/14/140330bt.jpg.

This side view shows a flower with four slender, greenish-yellow sepals, four yellow petals with broad outer parts narrowing to slender bases, or "claws," that attach just below the ovary. There are six yellowish stamens, of which two are shorter than the other four.

Well, every serious wildflower sniffer knows that these features point to the big Mustard Family, the Brassicaceae. And with such plump-looking ovaries (not long and very slender) on short stems, and pedicels held close to the main stem, we're directed to the mustard genus itself, Brassica. Though eight Brassica species are listed for North America, Brassica is an Old World genus, so all our Brassica species are invasive non-Americans.

An important field mark distinguishing our Brassica species from the other seven found in North America, are the lower leaves, of which a fungusy one is shown at http://www.backyardnature.net/n/14/140330bu.jpg.

Notice that where the leaf's petiole, attaches to the plant's stem at the picture's far right, no leafy material is in contact with the stem. Leafy bases of some mustard species wrap around the stem, or form leafy "ears" projecting backward from the leaf, but here there's just the naked petiole attaching to the stem.

This is the Black Mustard, BRASSICA NIGRA, an early-spring "weed" throughout much of the world, but precisely because it presents such pretty shows of yellowness at a season when folks are ready for bright colors in the landscape, they're not much resented. In fact, Black Mustard is a fair source of nectar for pollinating insects, so in some places it's welcome.

Traditionally, Black Mustard seeds have been the source of yellow mustard spread. If you have dried seeds, soak them a couple of hours, grind or mash them into a pulp, then stir in water while beating until you get yellow hot-dog mustard. You can do this with several mustard species, but Black Mustard is the tangiest.

The leaves also can be boiled like regular mustard greens, though they're so pungent that most people prefer to mix them into other dishes to soften their very mustardy flavor.

In traditional medicine, poultices have been made of paste made from ground Black Mustard seeds. The poultice is applied to the skin over aching joints or parts of the body just feeling bad, and can be applied to the chest for colds. Whole seeds mixed with molasses have been swallowed as a laxative, and in general mustard spice is said to stimulate appetites and serve as a tonic. There are so many uses that later in the spring, if the field in the picture hasn't been plowed under, I hope to collect sacks of seeds for my own use.


Thanks largely to the efforts of Lady Bird Johnson and her love of wildflowers, certain larger Texas highways are justly famed for the gorgeous displays of spring wildflowers along their sides. On smaller roads the usual policies of mowing and herbicide use produce the usual grass deserts.

Maybe the most cherished of Texas's roadside wildflowers is the Texas Bluebonnet, LUPINUS TEXENSIS, which is a lupine and a member of the vast Bean Family. Last year I didn't see a single Texas Bluebonnet, though I'm told that sometimes here their flowers turn large fields completely blue. At our spot on the upper Dry Frio it was too dry for them last year, people said. Since this year our area is much drier than last year, I figured another year would pass without my seeing a Texas Bluebonnet.

However, Monday when I biked the 35 miles from Uvalde to Juniper House, in several low spots in ditches along US 83 a few Texas Bluebonnets finally turned up. You can see part of a bathtub-size colony at http://www.backyardnature.net/n/14/140330lu.jpg.

Most bluebonnet species I've met were much larger than these. You can judge their size with my hand for scale at http://www.backyardnature.net/n/14/140330lv.jpg.

In that picture, notice that the flowering racemes' tops consist of immature, white flowers crammed close together, giving the racemes distinct "white tops." This is an important field mark to distinguish the Texas Bluebonnet from certain other species, especially the Sandyland Bluebonnet, Lupinus subcarnosus, which otherwise is similar and also produces vast displays of blueness, and which occurs in southeastern Texas, not quite reaching this far west. Racemes of the Sandyland Bluebonnet may produce one or two small white flowers at their tops, but nothing compared to the large white zone of several immature flowers seen on Texas Bluebonnets.

A close-up of some Texas Bluebonnet blossoms is at http://www.backyardnature.net/n/14/140330lw.jpg.

Notice that the upper flowers have white centers but the lower ones have purplish centers. To an insect's eyes, the flowers with purplish centers look all dark and uninviting, while the upper, more newly opened flowers with their white centers brightly attract pollinators exactly to their nectar zone. Once the flowers with white centers are pollinated, the white spots turn purplish, causing pollinators to stop visiting them and start paying attention to more newly opened, white-centered flowers above them, needing to be pollinated.

The Texas Bluebonnet, also called Texas Lupine, Buffalo Clover and Wolf-flower, is planted extensively along roadsides in Texas and Oklahoma, and is one of six lupine species designated as "the" state flower of Texas. Texas Bluebonnets occur in most of southern and central Texas, parts of Louisiana, and are planted in Oklahoma. They also grow wild in arid northeastern Mexico.


More common along US 83 north of Uvalde were the pretty wildflowers shown at http://www.backyardnature.net/n/14/140330al.jpg.

At first I thought they might be camas lilies or wild hyacinths, but camas lily/wild hyacinth flowers are arranged in a more slender raceme, while these flowers have their stems, or pedicels, arising close together atop the raceme stem, or peduncle. When hyacinth-type flowers are arranged like those in the picture, you need to crush one of the plant's leaves and smell. Very likely the odor will be that of onion, and that's what this plant is, a wild onion of the genus Allium. A close-up of a flower appears at http://www.backyardnature.net/n/14/140330am.jpg.

Lots of onion species are recognized -- between 550 and 700, depending on your expert. The Flora of North America lists 96 for our continent.

In our area we have two very similar wild onions species: Allium canadense occurs throughout the eastern half of North America, and; Allium drummondii is limited to the south-central states, extending into arid northeastern Mexico. Both species often produce onion bulbs, or "bulbils," in the flower cluster itself, but our roadside plants had none. Our pictures show ALLIUM DRUMMONDII, also known as Drummond's Onion, Wild Garlic and Prairie Onion.

In general, Drummond's Onion is larger and more robust that Allium canadense. Otherwise they're so similar that technical features are needed to distinguish them. One technical difference is that on Allium canadense the small, papery bracts, or scales, immediately below each flower cluster bear 3-7 pink veins, while on Drummond's Onion there's only one vein. I didn't know about that trick when I was photographing so I can't show it. However, looking at flower pictures of both species, it can be seen that the petal-like sepals of Allium canadense are slightly narrower, especially at their bases, than those of Drummond's Onion, and our flowers match the latter.

Both species arise from acorn-size onion bulbs, and those onions are not only edible but delicious if properly prepared and used. Many indigenous American groups ate them, and at certain seasons may have used them as a main food source, for often Wild Onion grows in huge populations.


Speaking of onions, you might be interested in seeing a commercial field of them just north of Uvalde, irrigated with aquifer water, shown at http://www.backyardnature.net/n/14/140330on.jpg.

A close-up showing how far apart the young plants are planated is at http://www.backyardnature.net/n/14/140330op.jpg.

I think the onion normally planted in this area is ALLLIUM CEPA 'Texas 1015 SuperSweet,' developed at Texas A & M University by Leonard Pike in 1980.


The above onion field was irrigated by water running down the troughs between raised beds. Many fields in the Uvalde area are irrigated by large sprinkler systems such as the one shown in a wheat field at http://www.backyardnature.net/n/14/140330ir.jpg.

Water enters the sprinkler system through the large pipes up front, then is sprayed downward through the nozzles dangling from the machine's arching "backbone." The whole system moves about in a large arc, pivoting at the tepee up front. That means that the most distant nozzles travel much faster than the nearest ones, and I guess it must be a challenge to ensure that the same amount of water is distributed across the field. It also means that looking down on the region from above, you see many green circles and partial circles in the otherwise brown landscape.

In the past, sprinkler systems of this type often sprayed water under high pressure into the air, like a lawn sprinkler. However, enormous amounts of water were wasted that way, through evaporation and wind-drift. The picture shows a low-pressure system that sprays as close to the crop as possible, to cut down on evaporation and drift, though in our arid climate much is still wasted. Drip or trickle systems are much more efficient, but those cost more and are more difficult to maintain.


Both the onion and wheat fields shown above are on ground that originally was "scrub" in which such trees as Mesquite and various species of acacia were dominant. You can see a general view of such nearby scrub as it appears now, with a nice Spanish Dagger flowering, and cholla and pricklypear cacti on the ground between mostly leafless small trees, at http://www.backyardnature.net/n/14/140330vw.jpg.


Each day I spend at least two or three hours doing physical labor, and that's a good time for thinking. For example, this week while scraping old paint and caulking a building to get ready for painting, my rambling thoughts followed this path:

Ever since the Big Bang some 13.8 billion years ago, the Universe has been expanding and evolving. When life on Earth arose about 3.5 billion years ago, it similarly began evolving and diversifying. Moreover, the crowning accomplishment of evolving life on Earth, human mentality, also has evolved and diversified.

Something interesting to notice is that the evolution of the Universe, of life on Earth and human mentality all developed along the same path: In each realm, things started out simple and became more complex and diverse. The Universe evolved into galaxies with stars and planets, Nature became a biosphere supporting enormous diversity, and human mentality diversified from brutish attention to moment-by-moment survival, into rainbows of mental perspectives, predispositions, emotional states, and esthetic senses.

All three evolutionary realms also share this feature: As evolution produced ever greater diversification, the resulting diverse parts interrelated with ever greater intimacy, and ever more sophisticated patterns of mutual influence. The Universe's stars and planets fell into a great dance based on interacting gravitational fields; Nature's living things grew ever more interdependent, and; now human interactions are expanding into a whole new dimension via such social media as Facebook, and maybe even these Newsletters.

At this point in the thinking process I find myself before blistering-off paint forgetting to chip at it, for it dawns on me that we can go further with this thought. If we accept that the evolutions of the Universe, Nature on Earth and human mentality all follow the same general path, we can "look into Nature" to see what becomes of diverse, interrelating things, to gain insight into what may happen with evolving human mentality. Finding such revelation in the Universe is hard, especially because 96% of it is "dark matter" and "dark energy" we can't see.

However, with life on Earth, the evolution of Nature is an open book. On the matter of what the most highly evolved organisms are like, it makes an interesting point. That is, of all organisms on Earth, the group generally regarded as the most successful and highly evolved is that of... parasites.

From an ecological perspective, what's special about parasites is not that they steal resources from others, but that they have adapted to specialized niches where the resources they need are dependably supplied with little effort of the parasite, and they can reproduce effectively.

If you think about it, that's precisely the way humanity is heading: Toward ensured security and comfort, and obsessive reproduction, just like the worms in our intestines. Already, as humanity consumes resources without returning them, we are weakening the global organism known as the biosphere with our parasitization.

Personally, thinking of humanity trending toward being like intestinal worms gives me the creeps, though I think there may be something to the insight.

I hope that, in the end, humanity follows "The Middle Path" -- neither continuing the unsustainable behaviors we indulge in now, nor becoming so absorbed in mental interplay that physically and psychically we end up withering to the condition of happily communing intestinal worms.



"Heat's Long-wavelength Thoughts" from the August 2, 2009 Newsletter, at http://www.backyardnature.net/n/p/090802.htm

"Thought Tangent of a Rainy Day" from the May 10, 2009 Newsletter, at http://www.backyardnature.net/n/p/090510.htm


Best wishes to all Newsletter readers,


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