June 16, 2013
COWBIRD EGG IN A PHOEBE NEST
Last week we looked at a nest of a pair of Eastern Phoebes on my neighbor Phred's back porch. This week, wanting to see if eggs had been laid, I pressed a downward-pointing camera against the porch ceiling about three inches (8cm) above the nest and took the picture at http://www.backyardnature.net/n/13/130616eg.jpg.
Eggs of the Eastern Phoebe are about ¾ inch long (2cm) and normally are white, sometimes speckled with reddish brown. But they're not as speckled as the very speckled egg in the center. That center egg, which also lacks the other eggs more pointed end, is an egg of the Brown-head Cowbird. Cowbird eggs are described as having a ground color varying from an almost pure white to grayish white, or sometimes pale bluish or milky white, with specks and blotches varying from brown or tawny to reddish brown.
Nests of Eastern Phoebes are known to be particularly heavily parasitized by Brown-headed Cowbirds. The female cowbird spots another bird species, such as our phoebes, building a nest, then the cowbird lays a single egg -- rarely more -- in the "host nest." The female cowbird may remove or destroy one of the original nest eggs. Sometimes the parents in whose nest the cowbird has laid her egg recognize that there's a problem and remove the cowbird egg, or build a new nest over the old nest, or abandon the nest entirely. Usually, though, the adopted parents continue with their nesting as if nothing has happened. Cowbird eggs normally hatch before other eggs in the nest. The cowbird nestling typically is larger than the other nestlings and grows so much faster that sometimes the smaller nestlings are crowded from the nest. The cowbird nestling may so aggressively beg for food that other nestlings starve.
Cowbirds mostly inhabit forest edges. During most of songbird evolution, forests were extensive with relatively limited "edges," so cowbird nest parasitization wasn't a huge problem. However, nowadays forests are so fragmented into tiny parcels that nearly everything is "edges," and the effect of cowbirds is more pronounced than before.
Still, a good case can be made that various "cowbird control programs" are useless and ethically questionable. A good discussion of the issue is provided in a PDF document you can download from the American Birding Association after using a search engine on the title "Brown-headed Cowbird: Villain or Scapegoat?"
That document argues that the effects of cowbirds are negligible in comparison to habitat destruction. That's a point I heartily agree with.
"BAROMETER BUSH" FLOWERING
In front of the cabin there's a ten-ft-high (2m) shrub much branched from the base with somewhat spindly stems bearing smallish, silver leaves. This week the bush has produced pretty, magenta flowers, as shown at http://www.backyardnature.net/n/13/130616cd.jpg.
Blossoms crowded among branch-tip tufts of leaves can be seen at http://www.backyardnature.net/n/13/130616ce.jpg.
In that picture notice that the leaves are two-toned; their upper surfaces are greener than their more silvery lower surfaces. A close-up of a single flower appears at http://www.backyardnature.net/n/13/130616cc.jpg.
In that picture notice that the corolla displays bilateral symmetry, which means that there's only plane across which you could cut the blossom so that each resulting half would be a mirror image of the other. Only certain plant families produce blossoms with bilateral symmetry -- with "zygomorphic" flowers, as we say -- so that's an important field mark. The blossoms, vaguely similar to snapdragon flowers, are about the size of a finger's last joint. You can see how nicely designed they are for bee pollinators.
The reason for the similarity with snapdragon flowers is that this bush or small tree is closely related to the snapdragons. Until recently they were both included in the Figwort Family, the Scrophulariaceae, but now, on the basis of DNA studies, snapdragons have been ejected from the family, while the tree in the front yard remains one of a few species remaining in the once large family.
The front-yard tree is commonly known by its Spanish name, Cenizo, but it's so abundant in some places and well regarded as a pretty shrub able to handle long periods of drought, that it's well known enough to go by several English names, including Barometer Bush, Texas Ranger, Texas Rain Sage, Texas Silverleaf, Ash-bush, Wild Lilac, and Purple Sage. It's LEUCOPHYLLUM FRUTESCENS, mostly found in arid northern Mexico, but entering the US in Texas, where mostly it shows up in the southwestern counties.
Two hours west of here, in the Rio Grande Valley at Del Rio, sometimes you see vast spreads of Cenizo. I've not found it growing wild here at the edge of the Edwards Plateau, but it does occur in the scrub of southern Uvalde County just to our south and lower in elevation. I can't say whether the one in front of the cabin is transplanted from the wild or is a horticultural cultivar. It might be the latter, because I'm used to seeing them paler, lower and wider than this one, but that's in more desert conditions.
Several cultivars of this fine shrub have been developed, graced with such names as 'Green Cloud', 'White Cloud', 'Compacta', 'Convent', and 'Bert-Star.'
Its names Barometer Plant and Texas Rain Sage reflect the local belief that the bush "knows" when it's about to rain and issues its flowers a few days in advance of a rain. The shrub in front of the cabin began flowering about a week ago. Last Sunday night we had the best rain of the year, over an inch, and this week we've enjoyed several showers, so this time our bush got it right.
PRICKLYPEAR CACTUS SEEDLING
In very thin, dry soil exactly at the lip of a limestone cliff dropping to the little Dry Frio River behind the cabin a couple of cylindrical, four-inch tall (10cm) cactuses showed up, one of which is shown at http://www.backyardnature.net/n/13/130616op.jpg.
A close-up of the cactus's clusters of spines appears at http://www.backyardnature.net/n/13/130616oq.jpg.
In our area we have cylindrical cactus species bearing clusters of numerous slender spines radiating from a point, as shown above, but I've not seen them in the wild, despite our being in their area of natural distribution. You see them in people's yards, and I'm guessing that basically that species has gone extinct in this area because of people digging them up.
However, even mature pricklypear cactuses with flat, beavertail-shaped stem segments, or pads, start out as cylindrical seedlings, and that's what I think is shown in the picture. Since several large, prolifically fruiting Texas Pricklypears, Opuntia engelmannii var. lindheimeri, were growing just a few feet away, so I'm supposing that that's what is shown in the picture.
In the last picture notice toward the cactus body's top, in each spine cluster a single spine is pinkish and more robust than the surrounding paler and much smaller spines. Mature spine clusters of the Texas Pricklypear normally develop only one or two large spines per cluster, as you can see on our Texas Pricklypear page at http://www.backyardnature.net/n/h/tx-prick.htm.
Nowadays early each morning, in disturbed, grassy areas such as lawns and roadsides, it looks almost like dandelions are flowering, until you get up close. Then you see that these plants' flowering heads arise on stems that not only are branched but also bear leaves, and you know that dandelion flower stems aren't branched and don't bear leaves. This is something else, as you can see at http://www.backyardnature.net/n/13/130616py.jpg.
In that picture the item below and to the left of the flower is an old head from which cypsela-type fruits already have been lost, and even that looks very much like a spent dandelion head. So, what is this almost-dandelion?
At http://www.backyardnature.net/n/13/130616pz.jpg you see that our plant's flower head seen from above sure looks like a dandelion. The head bears no disk flowers in an "eye," and each ray flower is tipped with five little teeth, which are vestigial corolla lobes -- all just as with dandelions. If you look at the flower head from below you see that the green bracts, or phyllaries, are in two series, a row of short outer ones at the bottom and a row of much longer, inner ones above the shorter ones, also pretty much as with the Dandelion. You can see them at http://www.backyardnature.net/n/13/130616px.jpg.
Breaking open a flower head you find that atop each cypsela-type fruit there's a white "parachute" consisting of many very slender, white hairs, shown at http://www.backyardnature.net/n/13/130616pw.jpg.
The white hairs make up the pappus. Notice that each cypsela's top narrows to a short neck. As the cypsela matures and grows, the neck will elongate and the white-haired pappus will become a white parachute carrying the fruit on the wind, just as with Dandelions.
Obviously, on the Evolutionary Tree of Life, this plant occupies a twig tip very near the dandelions. In fact, it's what often is called the Texas Dandelion, but outside of Texas maybe it's better known as the Smallflower Desert-chicory. It's PYRRHOPAPPUS PAUCIFLORUS, fairly closely related to the dandelion, but in a different genus. The Texas Dandelion occurs in arid northern Mexico and in the US south-central states from Arizona to Florida.
Each morning the Texas Dandelion's flower heads boldly show up yellow on green grass, but if it's sunny the heads close up after three or four hours and by noon it's hard to locate a single plant because not a trace of yellowness shows anywhere.
In a paper appearing in the Papers of the Peabody Museum of American Archaeology and Ethnology it's reported that the Navajo used Texas Dandelion's branched, leafy flower-stalks as a ceremonial emetic.
Behind the cabin there's a population of small herbs so short and ground-hugging that the landowner's lawnmower didn't get them, and the plants are so thickly woolly with cobwebby hairs that you can't make much of them. You can see what they look like at http://www.backyardnature.net/n/13/130616di.jpg.
I've been watching the plants for weeks, expecting flowers to emerge from the cottony balls, but when they didn't I took a close look and decided that maybe they'd already flowered, down in the fuzz. You can see a 3/8ths-inch-wide (7mm) cluster of what I figured were flower heads at http://www.backyardnature.net/n/13/130616dl.jpg.
The same structure is viewed from the side at http://www.backyardnature.net/n/13/130616dk.jpg.
Teasing apart several such heads, I couldn't really find anything that looked like flowers, everything being obscured by white cotton. One feature about the plant I could indeed determine was that the stems branched in a somewhat "dichasiform" manner -- the stem makes a Y, then each arm of the Y also splits to form a Y. The branching isn't perfectly dichasiform, just generally so, as you can see at http://www.backyardnature.net/n/13/130616dj.jpg.
The super woolly stems and leaves reminded me of the Rabbit Tobacco we looked at in our November 25th Newsletter. You can see Rabbit Tobacco at http://www.backyardnature.net/n/h/rabbit-t.htm.
Therefore, guessing that this Lilliputian backyard plant might be related to Rabbit Tobacco, in the online Flora of North America I went to the group, or "tribe," of the Composite or Daisy Family in which Rabbit Tobacco is a member, and eventually figured out that our mysterious, super-woolly little plant is something listed in books as Spring Pygmycudweed or Many-stemmed Rabbit Tobacco. It's DIAPERIA VERNA, occurring in arid northern Mexico and the southernmost tier of US states, from coast to coast.
I suppose that beneath a dissecting scope and using needle-tipped probes one could eventually identify the flowers' parts. However, with my weak eyes and fumbling fingers, this is one plant I'm learning by the habit of its body, and not the geometry of its blossoms.
A SMALLER FOURNERVED DAISY
Among the spring wildflowers of eastern North America many different plant families are represented, such as the Lily, Iris, Rose, Buttercup, Mustard and Geranium Families, and many others. The fall flora, however, is heavy on members of the Composite or Daisy Family -- in which are found asters, goldenrods, sunflowers, coneflowers, eupatoriums, etc. Here in southwestern Texas the spring wildflower species have mostly been members of the Composite or Daisy Family. A more diverse selection of plant families occurs in disturbed sites in the valley, along roads and in weedy areas around houses, but on the thin soils of our limestone hills the Composite or Daisy Family reigns supreme in spring, summer and fall.
In fact, it's hard to keep all the little golden-flowered and white-flowered composites straight, especially because many of them belong to genera I've never heard of.
For example, in our recent Newsletter of April 21 we looked at the Four-nerve Daisy, Tetraneuris scaposa, abundantly occurring on thin soil of our hills' lower slopes. You can meet that little yellow-flowered daisy, and see that the four nerves are on its petal-like ray flowers, at http://www.backyardnature.net/n/h/4nerve-d.htm.
Nowadays Four-nerve Daisies are still flowering, but during the last couple of weeks a very similar but noticeably smaller version of what appears to be Four-nerve Daisies has suddenly appeared along roads, on hillsides and at woods edges. At first I thought they were just drought-stunted Four-nerve Daisies, but finally so many consistently small plants turned up that I had to check them out. You can see a small part of a house-size population along a road at http://www.backyardnature.net/n/13/130616t4.jpg.
A close-up of a single plant showing that -- unlike the Four-nerve Daisy -- its stem branches well above its base, appears at http://www.backyardnature.net/n/13/130616t5.jpg.
Therefore, this didn't seem to be a runty Four-nerve Daisy after all. However, the special field mark for Four-nerve Daisies consists of the four conspicuous nerves on the rays, so I wanted to confirm that our smaller plant didn't have those four nerves. Well, it did, exactly like the Four-nerve Daisy, as shown at http://www.backyardnature.net/n/13/130616t8.jpg.
These conflicting signals indicated that I needed to "do the botany," so I checked out the involucre beneath the flowering head, finding it consisting of two or three rows of very hairy scales, or phyllaries, of similar lengths, just like the Four-nerve Daisy's, as shown at http://www.backyardnature.net/n/13/130616t6.jpg.
Breaking open the head, no scale-like paleae were found separating the disk flowers forming the head's "eye," and the crownlike "pappus" atop each future cypsela-type fruit consisted of several low scales with needlelike tips -- all exactly as with the Four-nerve Daisy.
So, the story is that here is a second species of four-nerve daisy, one usually listed by wildflower-book authors as the Fineleaf Fournerved Daisy. It's TETRANEURIS LINEARIFOLIA, occurring throughout most of Texas, southern Oklahoma and southeastern New Mexico, and arid northeastern Mexico. The earlier, larger species was Tetraneuris scaposa.
The genus Tetraneuris is one I never heard of before coming here, but now here we have two species of fournerved daisies abundantly flowering in both the valley and on hillsides. Our present Fineleaf Fournerved Daisy is an annual with stems branching well above the base, while the stem of the earlier, larger Four-nerve Daisy branched only near the base, and it was a perennial.
But, unless you're paying particular attention, you'd probably never notice the difference between them.
All winter several basketball-size bunches of Parsley plants flourished beside the cabin. Their ferny leaves graced many delicious soups and salads. Now some of those plants have "bolted" producing impressive flower-heads. You can see one at http://www.backyardnature.net/n/13/130616pa.jpg.
Parsley, PETROSELINUM CRISPUM, is a member of the large and important Parsley Family, the Apiaceae, with more than 3,700 species distributed across 434 genera. As the families of flowering plants are interpreted now, the Apiaceae is the 16th-largest, being home to such well known plants as Anise, Caraway, Carrot, Celery, Coriander or Cilantro, Cumin, Dill, Fennel, Hemlock, Queen Anne's Lace, and Parsnip. You can see Parsley's distinctive, ferny leaves at http://www.backyardnature.net/n/13/130616pd.jpg.
A good field mark for the Parsley Family is that its species produce flowers clustered in umbel-type heads. An umbel is a flat-topped or rounded -- umbrella shaped -- flower cluster in which individual flower stalks arise from about the same point. One of our Parsley's umbels is shown at http://www.backyardnature.net/n/13/130616pb.jpg.
That picture shows one big umbel composed of several smaller umbels, or "umbelets" -- like an exploding fireworks rocket that issues smaller bombs that themselves explode.
Early in the morning, at the edge of younger umbelets, tiny flowers are seen with five male stamens alternating with petals, as shown at http://www.backyardnature.net/n/13/130616pe.jpg.
By mid-morning the stamens and petals fall off, leaving the female part, the pistil, which will become the future fruit, as seen at http://www.backyardnature.net/n/13/130616pc.jpg.
In that picture the white, finger-like items pointed upward are styles. The Yellowish, shiny bases beneath the styles are stylopodia, which are glandular disks whose secretions attract pollinators. Stylopodia occur only in the Parsley Family.
All sources I've seen describe Parsley plants as biennials, meaning that during the first growing season the plant forms a low rosette of leaves, the leaves overwinter, than on the second year flowers appear, and once mature fruits are produced, the plants die. However, I received these plants from Phred across the river, and he swears that this is at least these plants' third year. Moreover, some of the roots of this plant appear to have sprouts prepared to form rosettes this winter. I just don't know what to say about this.
I will say, however, that Parsley is a wonderful plant, not only because of its tasty herbage, but because it's so nutritious, containing unusual amounts of vitamins and minerals. It's even considered medicinal by many, maybe its most powerful service being as a diuretic. There's a belief that if something makes you pee a lot, it's cleaning out your body, plus the peeing helps with urinary infections. Pregnant women shouldn't use Parsley medicinally, however, because too much can cause problems. It's even stated that Parsley can be used to get rid of head lice. Make a Parsley tea by infusing it in hot water, let it cool, soak a towel with it, and after shampooing wrap the wet town around the head for 30 minutes and allow to dry naturally.
My neighbor Phred told me about a strange vine near his house that each year issues long stems across the ground, It produces large, yellow flowers like a watermelon or winter squash vine, but its leaves aren't like either of those, and its fruit, while a little similar to a watermelon, never gets much bigger than a softball. I'd never heard of such a thing so we went to take a look. You can see Phred feeling a leaf's rough surface at http://www.backyardnature.net/n/13/130616cu.jpg.
A close-up showing a tough, musky-smelling, sandpaper-surfaced, crooked-based leaf with a half-mature fruit below it is at http://www.backyardnature.net/n/13/130616cv.jpg.
The big, orange-yellow flowers were indeed very similar to those of my garden squash, so I wasn't surprised when the plant revealed itself to be a member not only of the Gourd/Cucumber/Squash Family, the Cucurbitaceae, but also belonging to the pumpkin/squash genus Cucurbita. It was CUCURBITA FOETIDISSIMA, commonly known as the Stinking Gourd, Coyote Melon, Buffalo Gourd, Missouri Gourd, Calabazilla, and other such names. It occurs in about the southwestern quarter of the US south to central Mexico.
This is such an extraordinary and potentially useful plant that it's surprizing that indigenous Americans didn't domesticate it as they did corn, squash and potatoes. Stinking Gourd's seeds are rich in oil (25-42% fat) and protein (22-35%), and its herbaceous shoots arise from a large storage root containing amazing quantities of carbohydrate in the form of calorie-rich starch.
An article entitled "The Feral Buffalo Gourd, Cucurbita foetidissima," by WP Bemis et al, and appearing in Economic Botany, Vol. 32: 87-95. January-March, 1978, describes a Stinking Gourd taproot whose top had a circumference of 4.7 ft (1.4m), and from which 60 perennial stems arose producing 360 annual shoots. The shoots spread out forming a circle like ours in the picture 40 feet across (12.2m). One taproot studied weighed 159 pounds (72kg).
In terms of eating Stinking Gourd's taproot, the problem is that the whole plant contains high levels of the triterpenoid glycoside called cucurbitacin, which imparts a very bitter taste and can be toxic in high concentrations. The plant also contains saponins in such high quantities that its sap when added to water and beaten makes a foamy soap for washing. The Western Apache mashed the stem, leaves and root, mixed with hot water, and used the resulting mass for treating saddle sores on horses.
Indigenous Americans also ate the seeds, but only after roasting or boiling them. The seeds can be eaten alone or ground into meal, which can be added to water to make a nutritious mush.
If indigenous folk and modern plant breeders haven't been able to remove Stinking Gourd's bitterness and toxicity, the developing market for biofuels has engendered a new interest in the plant as a potential biofuel crop for arid land. A four-year-old root grown under cultivation can attain a fresh weight of 99 pounds (45kg), which represents a fair amount of renewable energy.
When Malle the Estonian lady friend returned to Estonia a few weeks ago, as a going-away present she presented me with a potted squash plant bought at the Uvalde Wal-Mart. The plant didn't have a name on it, just a tag saying that all summer it'd produce large, yellow squash.
Transferred to the garden, the plant grew fast, soon becoming the most eye-catching and robust citizen of the garden. You can see the knee-high plant spreading its kite-size leaves over cardboard spread across the garden to conserve moisture, in lieu of having enough compost, at http://www.backyardnature.net/n/13/130616sq.jpg.
A close-up of flowers and a ten-inch-long (25cm) fruit is shown at http://www.backyardnature.net/n/13/130616sr.jpg.
The plant with its enormous, deeply divided, silvery-mottled leaves is very unlike other squash plants in the garden, and the squash fruits look a bit strange being so cylindrical and with faint ribs, so what is this?
We can all see that it's a member of the Squash/Gourd/Melon Family, the Cucurbitaceae. But that's a big, important family, embracing some 125 genera and 960 species. Of all plant families, a webpage sponsored by Purdue University says that the Cucurbitaceae produces the most species used as human food.
If you "key out" which Cucurbit genus our plant belongs to, when you notice that the fruit is fleshy and not splitting open when mature, that the fruit contains many seeds, that the corolla's lobes join together to form a bell-shaped corolla, and that the stamens' baglike, pollen-producing anthers attach to one another forming a single anther mass, you find that you have the genus Cucurbita, in which occur pumpkins, squashes, certain gourds, and the like. Cucurbitaceous species not in the genus Cucurbita include the cucumber (genus Cucumis), luffa gourds, and a large number of wild vines producing fruits you'd never think of eating.
By the way, you may be interested in seeing what the grown-together anthers of a squash flower's stamens look like. You can see it, with a Cucumber Beetle mugging for us, at http://www.backyardnature.net/n/13/130616ss.jpg.
So, we have something in the pumpkin/squash arena, but what is the species? Making the same kind of analysis and noting that the squash fruit produces white seeds, and that the leaves are deeply lobed and rather rough or scratchy feeling, we come to Cucurbita pepo, one of the most horticulturally important of all plants, a species from which many dissimilar fruits have been coaxed. Field pumpkins, yellow crookneck squash, acorn squash, egg squash, Zucchini, spaghetti, 'Delicata' squash and many other squashes all derive from this single polymorphic species. Cucurbita pepo is thought to have been domesticated first in Mexico. But, even in Mexico I've never seen anything like the one in our pictures.
Cucurbita pepo is regarded as being divisible into several varieties, including:
Of these varieties, the one producing large, fast-growing, cylindrical fruits with low, angular ridges or ribs is the variety cylindrica. Therefore, what we have is something very like a zucchini, maybe even just a yellow form of zucchini, which normally is dark green.
Figuring that out, on the Internet you can find squash fruits looking like ours labeled "Yellow Zucchinis" and "Golden Squash." They're hybrids, and different companies sell them under different names.
Whatever the name, this robust and beautiful plant is a wonderful gift, one that evokes pleasant memories and the prospect of some good eating this summer.
FEATURED ESSAYS FROM THE PAST:
"A Tree Not Far Away," from the November 14, 2010 Newsletter, at http://www.backyardnature.net/n/p/101114.htm.
"A Song in Every Tree," from the June 29, 2006 Newsletter, at http://www.backyardnature.net/n/p/060629.htm.
Best wishes to all Newsletter readers,
All previous Newsletters are archived at http://www.backyardnature.net/n/.
Visit Jim's backyard nature site at http://www.backyardnature.net