JIM CONRAD'S
NATURALIST NEWSLETTER
Issued from the valley of the Dry Frio River on the
southern slope of the Edwards Plateau, northern
Uvalde County, southwestern Texas, USA

July 21, 2013

GOPHERSNAKE
It was one of those times when your reflexes take over and you find yourself doing something that surprises you. What I was doing was sliding my bike sidewise on loose gravel because an awfully big snake lay where my tires soon were to pass. Once I was standing astraddle the bike I found myself so close to the snake and the snake so long that I couldn't get his entire body into my camera's viewfinder. You can see the snake's front end at http://www.backyardnature.net/n/13/130721sn.jpg.

The bold patterning was similar to that of a rattlesnake but being so close I could easily see the eye's round pupil, and of course rattler pupils are cat-eyed, like vertical slits. A close-up of the head showing the eye and facial scales better -- and the snake inflating his throat -- is at http://www.backyardnature.net/n/13/130721so.jpg.

Taking into account that big snakes always look larger than they really are, I figured that this one was between six and seven feet long (2m). The back's dark blotches reminded me of a rat snake, but upon noticing the series of slender, black, vertical lines both above and below the mouth, and the snake's unusual thickness, I remembered the Gophersnake, PITUOPHIS CATENIFER, which we last met in California's Sierra Nevadas. That was the subspecies catenifer, however; this is a slightly different looking one, subspecies sayi. Gophersnakes are sometimes called Bullsnakes.

I read that when Gophersnakes feel threatened they coil themselves into the strike pose of rattlesnakes, but then attack with their mouths closed, hitting with their blunt noses -- a gesture that might scare off most predators. Sometimes they shake their tails like rattlesnakes, and if they're in loose gravel or dry leaves it might even sound like a rattler rattling. Also, Gophersnakes sometimes gulp air and loudly hiss it out. Except for the inflated throat, which probably was gulping of air in preparation for hissing, I didn't witness any of these warnings. My snake just lay there, but when I dismounted the bike he began snaking through the grass, speeding up the closer he came to a thicket, until he disappeared there.

Gophersnakes are some of the nicest snakes you'd ever want to meet. Not only do they go to great ends to not actually bite their assailants, but also they eat lots of rodents. Sometimes they venture into ponds to hunt frogs. They're among our largest snakes, reaching eight feet or so (2.4m). In our area the Indigo Snake is bigger.

*****

A HORSEFLY'S HEAD
Of all the places I've settled at during the last few decades, except in chilly Europe, the little Dry Frio River Valley has the least numbers of ticks, mosquitoes and biting flies. We do have prodigious numbers of stinging fire ants, but they're in a special category. Other than the fire ants, the most pestiferous critters for me personally are gnats that as soon as I settle anyplace dive-bomb into my ears and eyes.

However, lately horseflies have been moving up on the bothersome scale. Sometimes even while peddling the bicycle down the road they land on my legs and start sawing at my flesh. You can see one on my leg at http://www.backyardnature.net/n/13/130721tb.jpg.

Goodwin and Drees's 1996 The horse and deer flies (Diptera: Tabanidae) of Texas tells us that just in Texas we have 109 species belonging to the Horsefly/Deerfly Family, the Tabanidae, so you can imagine that volunteer identifier Bea in Ontario couldn't go much further than to agree that our picture shows a fly in that family, except to say that "it is a 'she,' by the way, because of the space between her eyes." The compound eyes of male horseflies have no spacing between them, while you can see that our female's eyes are definitely separated. Only the females "bite," because they need nutrients in blood for their eggs.

The horsefly's compound eyes are composed of tiny units called ommatidia, and there may be as many as 30,000 of them per compound eye. You can see our fly's ommatidia beneath the dissecting scope at http://www.backyardnature.net/n/13/130721ta.jpg.

I happened to get an interesting picture of our fly's head, shown at http://www.backyardnature.net/n/13/130721tc.jpg.

The antler-like projections pointing toward the image's right side are the antennae. The downward-directed item is the mouthpart, the labium. When a fly lands on you and sops up sweat, you can watch how he directs the labium's oval, spongy tip to this and that wet spot. The labium is like a sheath wrapping around slender, sharp blades with which the fly can slash into our flesh to get at blood. In the picture, the sharply pointed, brown item between the labium and the antennae is one of two maxillary palps, which help the fly feel and maybe smell/taste whatever they touch.

*****

GUM BUMELIA
Nowadays on thin soil atop limestone bedrock a much-branched, thorny bush or small tree with distinctively small, simple leaves broader toward their tips than their bases occasionally is seen issuing globular clusters of tiny, white flowers, as shown at http://www.backyardnature.net/n/13/130721bm.jpg.

Though the flowers, only about 1/8th inch wide (3mm) are so small and simple that it's hard to make much of them, if you look very closely you do see something unusual, which is apparent at http://www.backyardnature.net/n/13/130721bl.jpg.

There you can barely make out the greenish calyx below the corolla's five white petals, as well as whitish stamens with their oblong anthers suspended above the flower's interior. It's the stamens' position that's unusual. For, in the vast majority of flowers with five calyx lobes, five petals, and five stamens, the corolla lobes arise between the calyx lobes, as they do in this flower, but also the stamens arise between the corolla lobes. In this blossom the stamens arise opposite the petals, not between them.

This is such an unusual feature that it considerably helps us narrow down the plant families the tree possibly could belong to. In our area, if you find a woody shrub or tree with flower parts in five, and the stamens are opposite the petals, the plant families that come to mind are the Buckthorn Family (Rhamnaceae), the Ebony Family (Ebonaceae), and the Sapodilla Family (Sapotaceae).

The Buckthorn Family holds the Hogplum we looked at awhile back, but that tree's flowers were very different. The Ebony Family is home to the Texas Persimmons we've looked at, but these aren't persimmon flowers, either. In fact, our spiny, roadside tree belongs to the Sapodilla Family. It's SIDEROXYLON LANUGINOSUM, known variously as Gum Bumelia, Gum Bully, Woollybucket Bumelia, Chittamwood, Gum Elastic and Coma.

In Mexico often we admired the Sapodilla Family because some of tropical America's most cherished fruit trees belong to this family. There's the Chicozapote or Sapodilla, Mamey, Star-apple or Caimito and Canistel, all trees providing deliciously sweet and juicy, fair-sized fruits. In phytogeographical terms, our roadside Gum Bumelia can be thought of as a runty representative of a predominantly tropical family trying to invade the northern Temperate Zone.

Like many of its cohorts, Gum Bumelia's fruits are edible and fairly good tasting, but they're so small that few people bother with them, only about 3/8ths of an inch long (1cm). However, such fruits, which are oval, blue to black berries, are perfect for birds and other critters.

The book Native American Food Plants: An Ethnobotanical Dictionary says that the Kiowa people used a "mucilaginous substance in the outer bark" as chewing gum. This sounds right, since in earlier times Mexico's Chicozapote or Sapodilla, in the same family, was the source of the latex from which the first chewing gum was made. Modern gum in the US is made from synthetic materials.

*****

GULF COAST SPIKERUSH
On the upstream side of a concrete culvert on the little Dry Frio River a garage-size community of knee-high spikerushes looked very pretty in the dazzling sunlight, their golden flower spikes pointed skyward like stiff little fingers. You can see a small portion of the community at http://www.backyardnature.net/n/13/130721el.jpg.

A close-up of a flowering spike showing slender styles deployed to catch pollen swirling around them in the morning air appears at http://www.backyardnature.net/n/13/130721em.jpg.

With the single, fingerlike flowering spike atop a cylindrical stem, it's easy to recognize this as a spikerush, spikerushes being species of the genus Eleocharis in the big Sedge Family, the Cyperaceae. Some spikerush species are larger or smaller than our culvert species, some bear shorter, thicker spikes much broader than the slender, apparently leafless stems below them -- which is unlike our species -- but, in general, they are all structured pretty much like our culvert one. Once you have met two or three spikerush species, henceforward you'll always recognize any spikerush as a spikerush.

But, knowing which species of spikerush you have of the 200 or so known ones -- of which 67 occur in North America -- can be harder to figure out. Still, when you "do the botany" on our culvert spikerush you find that it is distinctive enough to be relatively easily figured out.

Besides the fact that it's larger than most species, our culvert spikerush produces an unusually thick, spongy stem. If you peel back the stem covering you can see that the sponginess is produced by squarish cells, as shown at http://www.backyardnature.net/n/13/130721ek.jpg.

Behind each scale on the flowering head there resides a flower. Once the flower is pollinated, its ovary begins maturing into an achene-type fruit -- an achene being a kind of dry, one-seeded fruit. Spikerush achenes are highly distinctive. You can see one of our culvert spikerush's at http://www.backyardnature.net/n/13/130721ej.jpg.

The surface of our spikerush's somewhat flattened, oval achene is ornamented with a net-like pattern, while the surfaces of many spikerush species are smooth, or the pattern is different, maybe the cells much longer, or of different size. Notice that the top 1/3 of the achene is a little different in color and texture than the lower 2/3rds, and that there's a slight constriction at the boundary between the two parts. The top part is referred to as the tubercle, and among spikerushes tubercles also come in many shapes and sizes, so their appearance helps a lot with identification.

I'd seen this species before: in a mangrove swamp on the Caribbean Coast of the eastern Yucatan. This is ELEOCHARIS CELLULOSA, the Gulf Coast Spikerush, occurring in Mexico, Central America, the Caribbean area in general, along the US Gulf coast and, for some reason, a bit inland in Texas, to here. The online Flora of North America describes its habitat as "brackish to saline marshes, shores, ditches," but here we are far from salty water. However, our stream water contains a high concentration of dissolved calcium carbonate, so maybe that's good enough for the Gulf Coast Spikerush.

What a pleasure finding this old friend from the Yucatan here, as pretty here as it was there in its dense, close-packed colonies with all its little golden fingers pointing skyward.

*****

WOOLLY IRONWEED
In a prairie patch on the floor of the Dry Frio Valley the sun glared, the wind whipped the knee-high grass and mostly lanky, scraggly wildflowers into fast-moving waves, and the heat hammered on head and shoulders. Through eyes burning with sweat a cluster of bean-sized, purplish orbs showed up amidst the swirl of grass and stems, so I wiped the sweat from my eyes and looked closer. The plant body was almost lost in visual clutter of highly animated sun-glints and shadows, but the purplish orbs were something real holding their places there before me, something smiling there in the prairie; you can see a frozen moment of what I saw, the purple orbs at the top, right, at http://www.backyardnature.net/n/13/130721vn.jpg.

Kneeling down I found purple flower heads signaling yet another member of the huge Composite, Daisy or Sunflower Family, one of that subgroup of genera whose flowering heads bear no petal-like ray flowers along their margins, but rather are like cups or goblets holding only cylindrical disc flowers, as you can see at http://www.backyardnature.net/n/13/130721vo.jpg.

Already at this point of "doing the botany," three conspicuous field marks were apparent: the flowers' purplish color; the cottony hairs mantling the cuplike involucre below the flowers, and; the brownish tufts of hair poking from the involucre as seen in the picture's bottom, left corner. The brownish hairs are the pappi atop the cypsela-type fruits; they're the future "parachutes" on wind-disseminated fruits. A longitudinal section of a head better showing the pappi atop their closely packed cypselae within the involucre is at http://www.backyardnature.net/n/13/130721vp.jpg.

When I saw what's shown in the last picture I felt sure I knew which genus we had. Notice that at the base of each tuft of purple pappus hairs there's a circle of much shorter hairs or hairy scales forming a crown around the cypsela's top. In other words, in this genus the pappus consists of two distinct kinds of hairs. At the base of each pappus there's a ring of short scales or hairs, then inside the ring there's the usual long hairs that will form the parachute on the mature fruits.

These field marks distinguish the genus Vernonia, among which we find species known as ironweeds, and which are favorite wildflowers throughout much of North America. Some ironweed species are tall, robust plants that in late summer lead the onrush of fall wildflowers with large, pretty inflorescences of purplish flowers -- a purplish hue exactly like that of our prairie species.

Our prairie species is VERNONIA LINDHEIMERI, known as the Woolly Ironweed because of the white-woolly hairs covering their involucres and stems. The Wooly Ironweed is endemic just to central Texas, possibly a corner or Arkansas, and a bit of the contiguous Mexican state of Coahuila. It's described as living on calcareous soils and rocky banks, so our prairie on thin soil atop limestone is a good place for it.

Another good field mark for this herbaceous perennial is its narrow, slender leaves that protrude rather stiffly away from the rodlike stem, as shown at http://www.backyardnature.net/n/13/130721vq.jpg.

Both the narrow, stiff leaves and the woolly hairs are adaptations enabling the Woolly Ironweed to live in habitats drier than other ironweed can, so the Woolly Ironweed is a fine candidate for xeriscaping.

*****

SWALLOW-WORT
Occasionally you find dense tangles of a delicate-looking, small, wiry-stemmed vine bearing two slender leaves per stem node, the leaves being only about half an inch long (15mm), and often the vine is flowering profusely with tiny, white, star-shaped blossoms about the size of a mouse's eye, as shown at http://www.backyardnature.net/n/13/130721mt.jpg.

At http://www.backyardnature.net/n/13/130721mu.jpg a close-up of two flowers shows that from the sinuses between the five petals' bases, slender, sharp-pointed, fingerlike appendages arise, which don't appear in most other kinds of flowers. Also, in the flowers' centers, instead of the usual oval ovary topped by a slender style and pollen-grabbing stigma, there's some kind of thick, round-headed structure.

This week the vines' first pod-type fruits began splitting open, releasing white-parachuted seeds into the wind. An empty pod and a pod about to open are shown at http://www.backyardnature.net/n/13/130721mv.jpg.

While examining the vine, if you accidentally tear a leaf, the wound bleeds white latex, and that's an important field mark. Along with the flower type, opposite leaves, pod with parachuted seeds, the milky latex points us to the old Milkweed and Dogbane Families. The question of which of those two families our vine belongs to is moot because the Milkweed Family has been sunk into the Dogbane Family.

So, here we have a member of what used to be the Milkweed Family, but now is the Dogbane Family, the Apocynaceae. It's the MacCart's Swallow-wort, CYNANCHUM MACCARTII, a rather uncommon little vine occurring only in southwestern Texas and adjacent northeastern Mexico. It's common here, just not found in other places.

The name swallow-wort is applied to several species in different families.

I'll bet that in the old days this vine was used medicinally, because members of the Dogbane Family often contain very powerful alkaloids in their milky sap, plus nearly always plants oozing white latex are regarded as medicinal by various cultures.

*****

SPEARMINT
When I arrived in the Dry Frio River Valley last year, behind the red cabin in which I lived there was a leaky faucet next to a tree, beneath which someone thoughtfully had planted mint, so all winter we enjoyed many cups of steamy mint tea. The mint plant was spreading into the grassy lawn despite regularly being mowed down. It was the same kind of mint that during my Yucatan years was grown in prodigious quantities in a kitchen-size, daily-watered bed by Don Filomeno, for use in the resort's kitchen. It's a tough, easy-to-grow, even aggressive mint, one that spreads fast by leafy stolons. It's amazing to have such a pleasingly aromatic herb that can not only defend itself but even grow like a weed when given half a chance. You can see a sprig of the red cabin's faucet mint at http://www.backyardnature.net/n/13/130721md.jpg.

Calling something a mint isn't being very exact. In doing so, are we referring to any member of the big Mint Family, the Lamiaceae, which embraces about 3500 species in 220 genera? Many Mint Family members don't smell minty or look much like the herb in our picture. There's a "mint genus," Mentha, to which belong such classic mints as Spearmint and Peppermint, but if we limit our concept of mint to Mentha, that leaves out such famously minty herbs as Catnip, Horse-Mint, Marjoram and Thyme. To be honest, many minty plants are so similar that often I confuse them. For example, during these years of having the kind of mint in our picture as a neighbor, I've never been perfectly certain which mint it was.

That's because mainly a flowering plant's identity is revealed by its flowers and fruits, but all during my years next to Don Filomeno's mint bed in the Yucatan, and for the last year here, the mints haven't flowered. All this time I've been waiting for at least one sprout to produce flowers, so I could identify with certainty which mint it really was.

Last fall, hearing that the lawn mower was preparing for a visit, I dug much of the mint next to the water faucet and transplanted stem segments into pots so I could give mint plants to anyone who wanted them. Now I have several dozen pots growing and I'm looking for takers. Thing is, none of the plants have produced flowers -- except for one in a pot off in the corner that maybe didn't get watered enough. Maybe that plant got stressed and the stress caused the plant to flower. Whatever the case, you can see its much-awaited inflorescence at http://www.backyardnature.net/n/13/130721me.jpg.

A close-up of one of its 1/8th-inch-long flowers (3mm) is at http://www.backyardnature.net/n/13/130721mf.jpg.

Having a flower, now I could "do the botany." Significant field marks include the following: The slender inflorescence arises at a stem tip, not from leaf axils; The flower bears four stamens (some in the Mint Family, like Rosemary and Sage, have only two), and; The corolla is almost but not quite radially symmetrical (most Mint Family members produce conspicuously bilaterally symmetrical flowers). Notice that the flower's top corolla lobe is not only a little wider than the other three lobes, but it bears a shallow notch at its tip (Actually it's two lobes fused along most of their common margin). These features and the plant's herbaceous, non-woody form lead us to the mint genus, Mentha, so now we figure out which species of Mentha it is.

The inflorescence's slender form, the leaves' having practically no petiole, and bearing saw-like teeth along their margins, and the hairless (glabrous) leaves and stems all direct us to: MENTHA SPICATA, the Spearmint.

Seeing the species name "spicata," meaning "spearlike," we realize that the name Spearmint means "the mint that bears spears" because the spears are the slender inflorescences tipping the herb's branches. If the flowers had been in more or less spherical clusters separated from one another along the stem and occurring in leaf axils, our plant might have been Peppermint. Spearmint's "spears" mean something!

Not only does Spearmint tea taste good but it has a long history of being used medicinally against such ailments as indigestion, cramps, flatulence, nausea, vomiting, colic and intestinal worms.

My impression is that many folks who have Spearmint in their gardens see how lustily it grows and lose some of their admiration for the plant, even to the point of mowing it down. That's a shame because this is a spectacular species -- a native of Eurasia -- worth taking care of, and remembering to use from time to time. Just grab a handful of stems and leaves, drop into a pot of boiling water, and drink, with or without sweetener.

At http://www.backyardnature.net/n/13/130721mc.jpg, see if that picture of a Spearmint leaf glowing in morning sunlight doesn't strike you as emanating some kind of transcendent benevolence just by being itself, right now.

*****

YARDLONG BEAN
My fence-climbing Yardlong Bean vines are producing, as shown at http://www.backyardnature.net/n/13/130721yd.jpg.

A close-up of a Yardlong Bean's pretty, papilionaceous flower is at http://www.backyardnature.net/n/13/130721ye.jpg.

Yardlong Beans are VIGNA UNGUICULATA ssp. SESQUIPEDALIS, and they're known by other common names such as Asparagus Bean, Snake Bean, Chinese Long Bean, Pea Bean and Long-podded Cowpea.

Yardlong Bean's subspecies name, sesquipedalis, is Latin for “a foot and a half long,” which is a more honest description of the Yardlong Bean's pods than the common name, for the legumes average not a yard long but rather about a foot and a half. The Latin "sesquipedalis," by the way, also is the root for the word "sesquipedalian," which means "tending to use long words."

Anyway, noticing that Yardlong Beans are members of the genus Vigna, and not the green bean or snap bean genus Phaseolus, we're alerted to the fact that, despite their outward similarities, Yardlong Beans aren't very closely related to green or snap beans. Last week we looked at green beans so maybe you remember that an important field mark for flowers of species in the genus Phaseolus is that the "keel" part of the blossom is coiled -- the keel being the scoop-shaped structure formed by the flower's two lower petals fusing at their common margin. Our picture of a green bean flower with its side petals, or "wings," pulled back to show the coiled keel remains at http://www.backyardnature.net/n/13/130714bp.jpg.

You can compare that with a Yardlong Bean flower with its wings pulled back to show the flower's keel at http://www.backyardnature.net/n/13/130721yf.jpg.

That keel is not at all coiled. The non-coiled keel plus some other more obscure features are significant enough to ban Yardlong Beans from the green bean genus Phaseolus, and assign them to Vigna.

The genus Vigna is worthy to know because it's also the home of mung beans, known by those who sprout beans to eat, and Azuki beans, known to certain discriminating gardeners, as well as black-eyed peas, sometimes called cowpeas. In fact, black-eyed peas are just a different subspecies of the same species that the Yardlong Bean belongs to. Black-eyed Pea plants are Vigna unguiculata ssp. unguiculata.

I first saw Yardlong Beans growing in an isolated Maya village on a mountain slope in southern Guatemala, so I've always figured that they were native to Mexico and Central America. However, genetic sequencing suggests that the wild, ancestral species' home may have been central Africa, perhaps Ghana. The Yardlong Bean subspecies, however, is a cultivar thought to have been developed in eastern Asia. Guatemala's Maya people may have received the cultivar from their Spanish conquerors 500 years ago, time enough for them to have developed their own strains.

Nutritionally, Yardlong Bean pods are regarded as very good sources for vitamin C, folate, magnesium, and manganese. 100 grams of them, providing only 47 calories, gives 23% of the daily requirement of vitamin C needed by an average person. Personally I don't see that Yardlong Beans are any more desirable than regular 'Kentucky Wonder' pole beans, except for the novelty of growing such unusual pods.

*****

FEATURED ESSAYS FROM THE PAST:

"Right Brain, Left Brain," from the July 7, 2008 Newsletter, at http://www.backyardnature.net/n/p/080707.htm.

"Religion, Atheism & The Middle Path" from the October 25, 2009 Newsletter, at http://www.backyardnature.net/n/p/091025.htm.

*****

Best wishes to all Newsletter readers,

Jim

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