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

February 23, 2014

LONGJAWED ORBWEAVER
We're having a series of warm days now and butterflies, spiders and other invertebrates are warily making their appearances, though we'll certainly have some frosts later on. One spider catching my attention was a slender-bodied one suspended in its web strung among diffuse branches of a grass's spent panicle, shown at http://www.backyardnature.net/n/14/140223lj.jpg.

It measured only about 2cm from front leg tip to back leg tip (¾inch) and what's curious is how it pulls in its side legs, unlike many species who spread all their legs widely when they perch in their webs. When disturbed, this spider drew in its side legs even more, presumably making it less visible to predators, as shown at http://www.backyardnature.net/n/14/140223lk.jpg.

Something to notice in that picture is that inside the space framed by the bases of the front legs some unusual structures can be seen. If the spider really gets upset, it abandons its narrow-profile strategy, stretches out all its legs, and starts trying to escape. You can see this happening at http://www.backyardnature.net/n/14/140223lm.jpg.

Volunteer Bea in Ontario figures that we have a member of the genus TETRAGNATHA, members of which often are named Longjawed Orbweavers, or Stretch Spiders. The curious structures at the front of the head appear to be two different kinds of mouthparts. The darker, thicker parts nearest the face are "jaws," more technically known as chelicerae, and which bear fangs, while the slenderer and more extended parts are the pedipalps, which serve as "feelers."

About a dozen Tetragnatha species are listed for Texas and I'm not sure which one this is. It's smaller than most.

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FIRST SWALLOWTAIL OF THE YEAR
This week's unusual warmth encouraged several butterfly species to emerge, the largest being the Pipevine Swallowtail shown at http://www.backyardnature.net/n/14/140223sw.jpg.

An abstract close-up of color details of the hindwing can be admired at http://www.backyardnature.net/n/14/140223sx.jpg.

Our Pipevine Swallowtail page has more info on the species, as well as pictures of its caterpillar and pupa, at http://www.backyardnature.net/n/a/pipeswal.htm.

That page makes the point that one of the great mysteries here is why we see so many Pipevine Swallowtails, but so far no Pipevines, said to be the only food of the Pipevine Swallowtail caterpillar.

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MISTLETOE FLOWERING
Mistletoes come in separate male or female plants. The unisexual flowers are tiny and much reduced in structure, as you can see on some spikes with flowers clustered in rings at http://www.backyardnature.net/n/14/140223ms.jpg.

A close-up of three female flowers is shown at http://www.backyardnature.net/n/14/140223mt.jpg.

You can see that the flowers have no petals but rather a fairly fleshy, three-lobed calyx forming a deep bowl around the sexual part. At the bottom of each calyx bowl there's a greenish ovary atop which stands a broad, blunt stigma head, which is where pollen from other flowers needs to land and germinate.

I wouldn't have noticed that the flowers were mature and functioning without the help of some flies. Two fly species were "working" the spikes just like a honeybee might, though they didn't appear to be inserting their mouthparts into the calyx bowls. It looked as if they were being attracted to the flowers but couldn't find what they were looking for.

Seeing this, I wondered whether the flowers might be issuing a carrion odor the way some orchids and other plants do, to attract flies to serve as pollinators. I couldn't smell a carrion odor and I've never read that this might be the case.

Back at Juniper House, some Internet browsing informed me that wind and many kinds of insects pollinate mistletoe. Although hundreds of kinds of insects carry mistletoe pollen, only a few dozen are important pollinators; these include a variety of flies, ants, and beetles.

I'm glad to park this observation here so that future researchers will know that in southern Texas in February it sure looks like mistletoe flowers are attracting flies in more than a casual manner.

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THE ODDBALL RUSTY-GILLED POLYPORE
Way up the canyon along the road years ago someone left on the ground what at one time must have been a pretty good four-by-six board. Now it was weathered and decaying. When I turned it over to see if anyone interesting sheltereded below it, I found sticking to the board's underside what's shown at http://www.backyardnature.net/n/14/140223fu.jpg.

We've all seen shelf or bracket fungi, those sometimes big and sometimes tough mushrooms emerging from the sides of sick or dead trees or logs like huge ears. Normally such fungi are attached by their sides, with a distinct cap above and spore-producing gills or pores below. What's in the picture appears to be nothing but gills, with the cap completely absent. Beneath the board the gills had been pointing downward, as they should to release spores.

Seeing that a fungus could configure itself so strangely was just the beginning of my introduction to a spectacularly nonconformist species. Its features were so inconsistent with my preconceptions about how a fungus should behave that I ended up having to identify it not by its technical features, but by browsing the Internet looking for labeled pictures. And I did find pictures, looking just like ours.

It's the Rusty-gilled Polypore, GLOEOPHYLLUM SEPIARIUM, and if you know the basics about mushroom classification probably calling this a polypore sounds wrong. Polypores release their spores from pores on the mushroom's undersurface, not from gills such as those shown by our polypore. All decent mushroom hunters know that you just don't get polypore-type mushrooms with gills.

However, our Rusty-gilled Polypore is a polypore with gills. Gene sequencers have confirmed that the species is a genuine member of the Polypore Order, the Polyporales. Many eons ago, during the course of mushroom evolution, polypores diverged from gilled mushrooms in the order Agaricales, and it's true that the vast majority of polypores do have pores, not gills, but the Rusty-gilled Polypore has gills anyway. A closely related species, Gloeophyllum trabeum, produces a mixture of gills, pores, and maze-like areas.

It's a matter of convergent evolution -- of gills evolving independently in fungi on different branches of the Tree of Life. You can see why gills would be such good adaptations: Because they so dramatically increase a fungus's spore-producing surface area relative to its mass.

Beyond all that, the Rusty-gilled Polypore's job in Nature is to decompose deadwood, especially of conifers such as pines, but sometimes also of hardwoods such as oaks. The board our fungus was attached to looked like pine; notice the black, shiny resin that's oozed from splits and hardened. The Rusty-gilled Polypore often occurs on lumber that's been stored too long, and old house decks constructed of pinewood, where its effects are said to constitute brown rot. Wood with brown rot looks brown, dry, and crumbly.

Rusty-gilled Polypores occur throughout most of North America and Europe, especially in the conifer zones. In the Dry Frio Valley we have no conifers except for a very few Pinyon Pines atop some isolated hills, so it's pretty impressive that our fungus managed to find a pine board in such an out-of-the-way spot.

*****

PORE LICHEN
On a stem of a Mesquite tree standing alone on the valley floor several lichen species had found a home, and one of them looked new for us. On the dark stem it presented itself as a smooth, white patch only about the size of a thumbprint. The center of the white patch was cracked into irregular blocks and each block bore one or two black dots, as shown at http://www.backyardnature.net/n/14/140223pp.jpg.

Several lichen species appear in that picture. Clearly there's fierce competition for twig space. If you study the picture you can see where other lichen species are encroaching onto our subject's body, and where our subject appears to be expanding itself. A close-up of is black-dotted center blocks is at http://www.backyardnature.net/n/14/140223pq.jpg.

Among most easily visible, or "macroscopic," lichens the typical fruiting body producing sexually derived spores is a cuplike structure known as the apothecium. This lichen's black dots are apothecia, but they're unlike most apothecia in that they're less like cups or bowls than blisters with holes in their tops. This is unusual, and it's a good field mark for this species. Another good field mark is that the lichen body and its apothecia are so tiny. The apothecia holes are at most only 0.8mm across (1/32nd inch).

This species works out as PERTUSARIA PUSTULATA, sometimes known as the Pore Lichen, occurring on tree bark in Temperate Zones worldwide. Lichens living on tree bark are said to be "corticolous."

On the Mesquite tree, Pore Lichen occupied only twigs that were three or so years old. It was absent from branch tips, as well as branches thicker than approximately a pencil. Larger branches were occupied by bigger lichen species, especially of the foliose and fruticose types, which easily grew over our low, humble Pore Lichen.

Whenever confronted with a tree loaded with lichens, it's fun to notice how the various species specialize in particular niches.

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AN OFFICIAL LICHEN MYSTERY
Exposed in the face of a cliff wall along the Dry Frio River a couple miles south of here there's a thin layer of conglomerate rock composed of pebbles and rounded stones cemented together with calcium-rich muck that hardened about 110 million years ago. A certain conspicuous lichen species I've not seen elsewhere occurs on this outcrop. The lichen presents itself as a pale greenish blotch with white fringes, but with no spore-producing, cuplike apothecia, as shown at http://www.backyardnature.net/n/14/140223le.jpg.

After comparing the lichen with literally thousands of pictures on the Internet, finally I found a match. However, the picture was on a page entitled "Lichen Mysteries," and it bore no name. The photographer, Stephen Sharnoff, annotated it with the remark, "A species of Lepraria?"

The Internet abounds in pictures of unnamed lichens, but Stephen Sharnoff's picture really got my attention. First, of all the places in the world it could have been photographed, it was found in Lost Maples State Natural Area just a few miles north of us in Real County.

Second, the photographer, Stephen Sharnoff, is not just any photographer of unnamed lichens. He's coauthor of the monumental, prize winning Lichens of North America, and sole author of the new A Field Guide to California Lichens. If he can't name our lichen, then I certainly can't, and there's a fair chance that what we have here is something "new to science." I wrote to Stephen and he put me in contact with an expert of the genus Lepraria, to which this species probably belongs. Lepraria species sometimes are known as dust lichens.

So, this is pretty good. I'll let you know if something comes of our genuine Lichen Mystery. Stephen's Lichen Mystery page, with our unknown appearing fourth from the top, is at http://www.sharnoffphotos.com/lichensH/lichen_mysteries_9.html.

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GREEN SCUM TURNING RED
With warmer weather more algae are returning to the little Dry Frio River, though it's contained a good bit all winter. Some algae species encrust rocks and aquatic plants, some form long, green strands trailing downstream, other species form submerged, basketball-sized masses, and others create blobs of bubbly scum floating at the water's surface. This week it was a scum blob bubbly with photosynthesized oxygen that caught my attention. You can see it at http://www.backyardnature.net/n/14/140223al.jpg.

What's interesting is that this otherwise green or greenish yellow alga has a reddish part. Until now I've not seen such reddishness in such a greenish blob, so I guessed that the reddish area consisted of algal cells that were under stress, or maybe coming to the end of their life cycle. I transferred some of the red part and some of the green part to a container, took the collection to Juniper House, and looked under the microscope.

The green part was composed mostly of filaments of Zygnema alga. You can see what normal Zygnema filaments look like on our Zygnema page at http://www.backyardnature.net/n/x/zygnema.htm.

Maybe 20% of the filaments were of Mougeotia alga, which we document at, at http://www.backyardnature.net/n/x/mougeoti.htm.

Examining the red part of the scum I found what's shown at http://www.backyardnature.net/n/14/140223am.jpg.

The spherical things are zygospores. Two algal filaments of different mating strains come into physical contact, the filaments' cell walls bulge toward one another at the point of contact, the bulges fuse and a tube forms between the two filaments. Genetic material from cells in both filaments flows into the connecting tube and sexually combines to form a zygospore. Eventually the zygospore breaks from the now-empty filaments, drops to the stream floor, and later germinates to form a new filament. This form of sexual reproduction is known as conjugation. In the picture not only do we see masses of zygospores but also some of the discarded, empty parent filaments.

Once I understood that the red part of the green scum consisted of zygospores and discarded filament sheaths, I began surveying the slide, looking for conjugation taking place. An interesting peep into this alga's conjugal life did turn up, shown at http://www.backyardnature.net/n/14/140223an.jpg.

The zygospore at the top, left is fully formed and ready to disassociate from its two empty parent filaments. At the far right another zygospore hasn't yet completely formed and you can see dark areas inside both parent filaments where material still is streaming into the zygospore tube. In the picture's lower, left corner, another zygospore is just beginning to form, with most of the material destined for making it still inside the parent cells, but a small part of it already in the tube between the filaments.

So, how about that? Who'd have thought that such fascinating stuff could be going on in the little Dry Frio these days?

*****

GARLIC CLOVE THERAPY
After building a new raised bed next to the greenhouse something had to be planted in it, and that thing was garlic, which can stand late frosts. It was regular garlic bought for eating from the supermarket. Just break apart the bulbs, plant individual cloves bottom down, four to six inches apart, cover them, water, and wait. The neighbor's wandering cattle keep us supplied with manure, which was mixed into the bed's soil, ensuring outrageously large and luscious garlic later on.

It's good seeing the cloves' smooth, glossy-green sprouts emerge from rich, crumbly, earthy smelling soil. In fact, just seeing them come up somehow is therapeutic.

It's especially therapeutic on mornings after listening to the news. You hear about the growing rate of elephant poaching for ivory, religious wars in Africa, the growing educational divide between the rich and non-rich... and then you go outside and see that during the night the garlic sprouts have added a little height, that wet with morning dew they're radiant in morning light, and you feel OK, maybe even a little hopeful.

Sometimes I think that the positive, restorative effects of beholding sprouting garlic cloves and other such gardening miracles are so immediate and so profound that there must be some deep, fundamental reason behind it.

A good guess is that it's because during the course of early primate and human evolution, those who survived to pass on their genes to us were the ones who most successfully and efficiently interacted with the plants and animals around them. Those early hominids and humans were self reliant, and kept things simple, so having a little garden beside one's house -- or even a potted plant in the window -- resonates with humanity's deeply rooted experience with Nature, self reliance and simplicity.

It's easy enough to test this theory. Just bury a garlic clove in a pot of soil set in the window, keep it warm and watered, and see what blossoms within you as the little green sprout rises from the rich, brown soil.

You can see one of my own perfect sprouts at http://www.backyardnature.net/n/14/140223gc.jpg.

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FEATURED ESSAYS FROM THE PAST:

"Self Discipline & Simplification --> Enrichment" from the April 26, 2009 Newsletter, at http://www.backyardnature.net/n/p/090426.htm

"Complexity & Simplicity" from the January 23, 2011 Newsletter, at http://www.backyardnature.net/n/p/110123.htm

*****

Best wishes to all Newsletter readers,

Jim

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