JIM CONRAD'S
NATURALIST NEWSLETTER
Issued from the woods a few miles east of
NATCHEZ, MISSISSIPPI, USA

July 15, 2012

FAWN BEING INVISIBLE
Wanting to photograph the hairs on the undersurface of a maple leaf, I carried the leaf into an opening where the light was better, turned on the camera, and for a tiny fraction of a second before the camera was set on macro and focused on the leaf, it seemed that in my viewfinder there stood the image of a spotted fawn -- the young of a White-tailed Deer, ODOCOILEUS VIRGINIANUS. Not ten minutes earlier I'd spooked such a fawn, who had erupted from behind a tree 15 feet (4.5m) away as I walked through the woods, but that fawn had fled like a fox half-flying, half fluttering on willowy legs, taking me a few moments to figure out what it was. But there'd not been time for a picture. How... ?

Reflexively and with my mouth dropped open I looked to where the camera had been pointed, and there ten feet away (3m) was what is shown at http://www.backyardnature.net/n/12/120715fw.jpg.

Beside a fallen log and fairly hidden from view by herbage all around, except for the small opening through which I peered, the fawn moved not at all. The morning was overcast, drizzly and the light was very dim, and that's one reason I'd managed to see the fawn, for its camouflage mimicked a sunlight-dappled forest floor, not a somber, rain-darkened one.

I didn't want the fawn to run away so I snapped the picture and moved on. Only when the image was on my laptop screen could I fully admire what I'd seen. Especially striking was how one of the fawn's ears was pointed exactly toward me monitoring my movements without the fawn having to look at me. On the other ear two ticks could be seen sucking blood. I think the white pattern on the fawn's black snout is a sticky spider web earlier nosed into.

If my camera hadn't by itself framed and focused on the fawn, I don't think I'd have ever seen it, despite being so close and facing toward it. The strategy of not moving is almost magical in the way it renders one "invisible." It seems that dumb luck -- good or bad -- can trump just about any strategy.

*****

SOUTHERN SUGAR MAPLE
Growing up in rural Kentucky I was very familiar with the Sugar Maple, the same species from which maple syrup is processed in the US Northeast and Canada. Sugar Maples line the streets of many little towns up there, breaking your heart with their loveliness on sunny October afternoons. Sugar Maples aren't native this far south, however, mostly petering out in the southern Appalachians of eastern Tennessee and western North Carolina. Knowing all that, the other day on a dry loess ridge near the trailer I was tickled to see what's shown at http://www.backyardnature.net/n/12/120715ac.jpg.

Northerners familiar with their maples will recognize that this isn't a Red or Silver Maple, but there's no reason why it couldn't be the Sugar Maple -- except, maybe, that its leaves are a bit smaller than usual. In fact this is the Southern Sugar Maple, ACER FLORIDANUM, in older books listed as Acer barbatum, and sometimes known as the Florida Maple. Southern Sugar Maples are endemic to the Southeastern US, spottily on the Coastal Plain and much of upland Arkansas. In southern Mississippi it's found here in the Loess Hills along the Mississippi River, for some reason avoiding the vast piney woods to the east.

It's clear that Southern Sugar Maples and northern Sugar Maples share common ancestors. However, there are notable differences. Northern Sugar Maple leaves average three to five inches across (8-13cm), while Southern Sugar Maple leaves are only 1.5-3 inches (4-8cm). Sugar Maple leaf undersurfaces are hairless, or bear hairs only along major veins, while Southern Sugar Maple leaves are hairy, as shown at http://www.backyardnature.net/n/12/120715ae.jpg.

The northern species can grow to 100 feet or so (30m) while Southern Sugar Maples seldom reach 60 feet (18m). You can see our Southern Sugar Maple's smooth, blotchy bark at http://www.backyardnature.net/n/12/120715ad.jpg.

The USDA's Silvics of North America describes Southern Sugar Maple's habitat preference as "fertile, moist but well-well drained soils on stream terraces, in coves, and on adjacent bluffs and ridgetops. It usually grows best on soils underlain by calcareous material such as limestone or marl." In our area it's uncommon and I've found it only on loess ridgetops. The loess is highly calcareous dust, so our trees must feel perfectly at home.

Maple syrup has been made from Southern Sugar Maples, but only to a very limited extent. The wood is as useful and pretty as Sugar Maple's, but its smaller, more shrubby form keeps it from being sought. In many southern towns it does perform the same street-tree service as its northern counterpart, displaying brilliant orange-yellow hues in the fall.

*****

PAWPAWS
Notes from my days as a hermit near here indicate that pawpaw fruits in this area mature in mid August or so. However, my experience is that if I want a picture of pawpaws hanging on a tree I'd best take the picture before the fruits ripen, else critters will pick them before I get to them. Therefore, you can see an immature pawpaw about 2-½ inches long (7cm) hanging on a Pawpaw tree on a rainy morning in mid July at http://www.backyardnature.net/n/12/120715pp.jpg.

If you were with me in the Yucatan you may recognize the similarity between this pawpaw fruit and the various annonas, soursops and custard apples we sampled down there. That's because Pawpaw trees are members of the same mostly-tropical plant family, the Custard Apple Family or Annonaceae, as the trees producing those delicious fruits. Our pawpaw fruits share with those tropical fruits their general size, the sweet taste of their soft flesh, the largeness of their many seeds embedded throughout the flesh, the small size of the trees, and many technical features. In fact, Pawpaws can be thought of as Temperate-Zone outliers of a family much more developed in the world's tropics.

Certainly as a farm kid in Kentucky when I was lucky enough to get a ripe pawpaw fruit it seemed that I was tasting something so lavishly musky-sweet, syrupy and messy that it felt exotic and over-the-top in comparison to the surrounding more understated and parsimonious oaks, hickories, maples and ashes. Now I know it was true: Pawpaws were simply otherworldly.

Pawpaw trees are an understory species living their whole lives in shade beneath taller trees, and they like rich, moist soil. Here they don't occur on ridge tops, but on valley floors and lower slopes where sometimes they form dense colonies. Fruiting trees usually are about 15 to 20 feet tall (5-6m). Sometimes during fruiting season you find large populations occupying whole little valleys but not a single tree will bear a fruit. Other times nearly every mature tree will be fruiting.

The common Pawpaw found throughout most of the eastern US and southernmost Canada is Asimina triloba. I'm supposing that what's in the picture is ASIMINA PARVIFLORA, sometimes known as the Small-flowered, Small-fruited, and Dwarf Pawpaw, native to the US Deep South, mostly on the Coastal Plain from southeastern Virginia to eastern Texas. Its distribution overlaps considerably that of the Common Pawpaw of farther north. In Mississippi the Common Pawpaw, Asimina triloba, is mostly limited to the northern two-thirds of the state, while the Small-flowered species, Asimina parviflora, occurs throughout the state, extending no farther north than about the Tennessee border. The main difference between the two species is seen in the flowers, but I have no flowers. However, the University of Mississippi's Pullen Herbarium documents collections of the Small-flowered species from our southwestern corner of the state, but not of the Common.

*****

REDBUDS FRUITING
Eastern Redbuds, CERCIS CANADENSIS, get plenty of press when the smallish but elegantly formed and leafless trees blossom so prettily in spring, but nowadays I'm enjoying seeing their abundant, black fruits dangling from the trees' sun-glowing, heart-shaped leaves, as seen at http://www.backyardnature.net/n/12/120715rb.jpg.

Redbuds are members of the Bean Family, so the fruits are legumes and the hard, black seeds inside them are beans. The legumes hang on the branches for a long time, sometimes through most of winter. During that time the pods' sutures split or the walls simply rot away, enabling the seeds to escape. On windy fall or early-winter days when the fruits flap wildly in the breezes, some seeds get thrown fair distances from their trees. Other fruits fall off and are blown even farther, with seeds still inside them. It's a sloppy, hit-or-miss seed dispersal strategy and that may explain why so many pods are produced, in the "hopes" that at least one or two beans among thousands will land someplace useful.

Redbud seeds have hard seed-coats, so the seeds need certain things to happen to them before they germinate. In nature germination is enhanced by fire, digestion by a bird or mammal, or partial breakdown of the seed coat by fungi or insects. Further, growth-inhibiting substances are present in the seed coat, the interior of the seed, and tissue surrounding it. Artificial breaking of the seeds' dormancy can be brought about by a 30-minute soak in sulfuric acid followed by a period of cold to break embryo dormancy.

Redbuds are mostly understory trees liking rich, moist soil, though often you see them invading abandoned farmlands. They're common throughout the eastern US, except for the northern states, and along the Gulf Coast. In southern Texas and much of northeastern Mexico there's an outlying population.

*****

MUSCADINES IN JULY
There's a picture that at first looks a bit uninteresting, but which shows some surprising details when analyzed, at http://www.backyardnature.net/n/12/120715vk.jpg.

That's the dry, sandy bottom of a deep ravine, or bayou as it's known here, with steep loess walls on both sides, not far downslope from my trailer. You can walk down such streambeds for miles here, hindered only by fallen trees.

Notice the green leaves occupying the picture's bottom, right. They're the same kind of leaf borne by the vine draping the tree trunk fallen across the streambed and they're the same on the vines massively covering vegetation in the background, occupying the entire upper center part of the picture. These are leaves of a woody-stemmed grapevine, and though I searched diligently among the leaves I couldn't find a single grape among all that viny foliage. However, around the bend, an otherwise undistinguished, low-hanging vine of the same kind but not nearly as robustly proliferating did bear some green, immature fruits -- and they were unusually large ones -- as shown at http://www.backyardnature.net/n/12/120715vi.jpg.

This is the famous Muscadine, VITIS ROTUNDIFOLIA, which since the 1500s has been used for making muscadine wine. Over 300 muscadine cultivars are grown in the US Southeast, known by such names as Black Beauty, Carlos, Cowart, Flowers, Fry, Granny Val, Ison, James, Jumbo, Magnolia and Memory, and they're all derived from this species, native from southern Delaware to Florida west to Kansas and Texas. The common wine-producing grape of history, the Wine Grape, is another species -- Vitis vinifera. In this area our Mascadine is the most common naturally occurring grapevine species, especially noticeable at woods edges, along streams, sometimes even scrambling into fields. The grapevine-dominated scene in our picture isn't unusual at all.

About 60 grapevine species -- members of the genus Vitis -- are recognized, nearly all native to the Northern Temperate Zone. Seven species are listed for Mississippi. Among all the grapevine species, the Muscadine is one of the easiest to recognize.

Typical grape species bear much larger, softer leaves. Also, usually they produce many more grapes grouped in elongated fruit clusters, not in few-fruited, rounded clusters like the Muscadine's. The bark of most grapevine stems shreds into long flakes but our Muscadine's stems are smooth, as shown at http://www.backyardnature.net/n/12/120715vj.jpg.

Maybe the most distinctive Muscadine grapevine feature of all is shown at http://www.backyardnature.net/n/12/120715vl.jpg.

That's a Muscadine stem groping into the emptiness above the bayou's dry streambed. The thing to notice is that the tendrils are not forked. Tendrils of Mississippi's other six grapevine species are forked, their tips being like the slender toes of a skinny crow's foot.

These distinctions between the Muscadine and other grapevine species reflect the fact that the Muscadine species branched off the grapevine evolutionary Tree of Life very early -- so early that the vast majority of grapevine species have 38 chromosomes, but Muscadines have 40. Two other wild grape species also have 40 chromosomes, so the along with the Muscadine form a subgenus, with some experts saying they need to be separated into their own genus. Because of the difference in chromosome numbers our Muscadine species mostly cannot hybridize with other grapevine species, and when they do cross-pollinate, the hybrids typically are sterile.

Interestingly, a week before I took these pictures, in the same bayou, many green to dark purple grapes littered the dry streambed, and every grape I opened had a worm inside it. This week I could find no such grapes. This means that something was eating them, which is to be expected, but it also indicates that at a certain rather precise time in the season the vines shed fruits with worms in them.

*****

PINEAPPLE PEARS
For the last couple of weeks my cuisine has been dominated by pears because trees in the orchard here are loaded with them. I eat them raw but mostly each day I cut at least six into my cornbread batter, so that now my main carbohydrate is more pear cobbler than cornbread. These pears are unlike those found in markets. I'd never seen anything like them until I came into this area. They're more spherical than "pear shaped," and even when ripe they are more greenish than yellow. They are so hard and gritty that most local people I've talked to don't eat them. However, they're juicy and sweet, are delicious when cooked, and soften into an appealing texture. You can see two typically green-mottled, only slightly yellowish fruits on a tree at http://www.backyardnature.net/n/12/120715pr.jpg.

During my hermit days in the woods of an old, historical plantation near Natchez, in a very old orchard where records showed that once a remarkable variety of fruit trees were grown, when I was there everything had died back except the figs, two or three apple varieties who were diseased and just hanging on, and this hard, green, spherical, gritty pear cultivar, which produced as prodigiously there as here. All along I've guessed that this pear is an old heirloom with disease resistance and toughness enough to thrive in our hot summers, but I've never been able to identify its cultivar name. This week I set about to learn its identity.

The first step was to ask Karen if she remembered what the guy told her who provided the saplings when she planted them here many years ago. "Pineapple Pear," she replied, admitting in the same breath that she's never been able to detect anything pineapplish about the fruit. I looked the name up on the Internet.

Many businesses sell "Pineapple Pear Trees" but the fruits produced by those trees are yellow and pear-shaped. Some pages give the technical name for that yellow, pear-shaped "Pineapple Pear" as Pyrus communis 'pineapple.' Still, among the dozens of Pineapple-Pear pages showing this yellow, pear-shaped fruit, a very few show what appears to be ours. Those pictures are mostly posted by others who have heard their pears called Pineapple Pears, but who are confused by seeing Internet pictures of Pineapple Pears that are yellow and pear-shaped.

Finally I found a grower in Florida, Chestnut Hill Tree Farm, featuring our pear, designating it as a hybrid between Pyrus communis and Pyrus pyrifolia. Its technical name therefore would be PYRUS COMMUNIS x PYRIFOLIA. Pyrus communis is the basic pear most pear from which most pear cultivars are developed, while Pyrus pyrifolia is a much less known species variously called the Asian, Chinese, Japanese or Sand Pear. Both species are native to Eurasia. The Asian Pear's fruits are spherical like ours, but golden instead of greenish. Chestnut Hill describes the hybrid between the two species as "a hard pear, that bears heavy crops of large, tangy pineapple-like flavored fruit -- good for cooking, canning or fresh eating. Fire blight resistant. Self-pollinating. Low chill (250 hours) for the coasts south to central Florida and coastal Texas. Bears in August."

That all sounds right for our pear, except that ours doesn't taste like pineapple and it's bearing in July. But here this year everything has developed weeks earlier than normal. One blogger apparently referring to our green pear says that it's called Pineapple because its mottled greenness with a slight tinge of yellowness is similar to that of a pineapple.

So, on the basis of having found this cultivar in an old-time orchard, and on what the Chestnut Hill folks say, here's what I'm guessing to be our pear's history: In the old days our green, spherical, hard, gritty pear was the original Pineapple Pear, planted mostly for canning and cooking. That original cultivar, a simple hybrid, gained fame as thriving in the US Deep South. Later horticulturalists came up with a new, only distantly related cultivar that also thrived in the Deep South, and they called it Pineapple Pear, maybe wanting to benefit from the fame of the original Pineapple Pear's name. Apparently the old Pineapple Pear name was purely traditional and never was formalized or protected by law.

In our picture, the hole in the pear at the right is typical; maybe 95% of our trees' almost-mature pears bear such holes, which are drilled by Red-breasted Woodpeckers who prefer drilling new holes in unblemished pears over continuing pecking in already-made holes. The trees are also much visited by Mockingbirds, Cardinals and Blue Jays, whom I suspect of pecking in woodpecker holes.

Here's one last bit of information relating to pear growing in the Natchez area: A neighbor said that of all the cultivars he's tried the only one that survives here is the LeConte. He didn't know about our Pineapple Pear heirloom, however, having learned his pomology at local garden centers.

*****

THE FIG-FLOWER SITUATION
The last two weeks have been fig season around here, which means that I've eaten two or three figs each day somehow overlooked by the birds. Now the figs are just about all gone.

In the Yucatan we had several fig species, all producing small, spherical figs, and the trees often grew to gigantic proportions. The fig species I'm talking about here is the Common Fig, FICUS CARICA, native to the Mediterranean region. It's a small tree with soft, sweet, golfball-size, pear-shaped figs.

Fig "fruits" are not fruits. When you bite into a fig you can see how unfuitlike the fig's interior is, as shown at http://www.backyardnature.net/n/12/120715fg.jpg.

The fig "fruit" is a fruiting structure called a syconium. Imagine a plate with many tiny flowers growing atop it, packed very close to one another. Now fold the plate's edges up to form a U, which brings the flowers to the inside of the U. Now bend in the top of the U until it's almost an O, but with a tiny hole in the O's top, the ostiole. This places all the flowers inside the O. That's a syconium. In the above picture, the pinkish, spaghetti-like structures attached to the fig wall, the receptacle, and growing inward toward the fig's center are flowers or the remains of flowers.

In Nature, a tiny "fig wasp" enters the ostiole at the fig's top and walks around inside atop the flowers, pollinating them.

Common Figs come in two sexual forms. Trees producing edible figs like ours are all female trees. Therefore, in the above picture, notice that the spaghetti-like structures bear spherical enlargements at their tops. Those spheres are ovaries. Immediately beneath the ovaries in some cases you can make out toothed calyxes just as in normal flowers. Below the calyxes the slender stems are pedicels, also exactly as in normal flowers.

The female flowers in our figs don't get pollinated and produce seeds, so in the figs I've been eating there's none of the "grittiness" found in some store-bought fig products.

In fact, Common Fig sexuality is pretty complex. A good place to delve more deeply into it is at http://waynesword.palomar.edu/pljun99b.htm.

*****

SOUTHWESTERN MISSISSIPPI'S RAVINE-BOTTOM SAND
About a year ago when we were staying at Mayan Beach Garden Inn on the Caribbean coast north of Mahahual on the Yucatan Peninsula's eastern coast we looked closely at the sand forming the white beaches there. You can see that "shell sand" at http://www.backyardnature.net/yucatan/shellsnd.htm.

Here in southwestern Mississippi the bottoms of deep ravines (locally called bayous) cut into deep loess deposits along the Mississippi River are floored with sand and gravel. You can see a close-up of that sand, which is very different from the above shell sand, at http://www.backyardnature.net/n/12/120715sa.jpg.

I understand the sand in our Loess Hill ravines as belonging to the Citronelle Formation, which was deposited here by being washed from hundreds of miles to the north approximately 1.5 to 3.7 million years ago, during the early Pleistocene and Pliocene epochs. A geological publication on the Internet describes Citronelle sand studied about 50 miles south of here in Louisiana as "subangular to well rounded, quartzarenite to sublitharenite sand containing about 90 to 95 percent quartz." In typical samples of sand in that study neither the minerals feldspar nor mica was noted.

Quartzarenite sand is basically sand formed of nearly pure quartz grains. Sublitharenite sand is sand with very little or no feldspar.

In other words, in Citronelle sand the vast majority of the grains are composed of quartz crystals. That's what we're seeing in the above photo. Quartz crystals are transparent, as are most of the grains. A fair percentage of the grains are tinged with amber color, indicating iron oxide content, making them the chert form of quartz. Feldspar usually is opaquely white or pinkish and I don't see such grains in the picture, or maybe just one or two pinkish ones. I recall that sand around my home in western Kentucky contained tiny, flat, thin, black or transparent, sheetlike grains, which were mica particles. There might be a very few tiny fragments of mica in our view, but not many.

So, I would say that here we have fairly unspectacular sand. However, as we continue to move about, it'll be interesting to see if more interesting grain types start turning up.

Sand along the Mississippi River not far away would be much younger and come from different places, so I'd expect it to be different.

*****

FEATURED ESSAYS FROM THE PAST:

"Sitting in the Rain Naked" from the June 27, 2004 Newsletter, at http://www.backyardnature.net/n/p/040627.htm.

"Raindrops" from the September 2, 2001 Newsletter, at http://www.backyardnature.net/n/p/010902.htm.

*****

Best wishes to all Newsletter readers,

Jim

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

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Visit Jim's backyard nature site at www.backyardnature.net