Naturalist Newsletter: Aug 29/ Garden Spider

[Rob]

JIM CONRAD’S NATURALIST NEWSLETTER
Issued from Hacienda Chichén beside the Maya ruin of
Chichén Itzá in the central Yucatán, MÉXICO

August 29, 2010

*****

GARDEN SPIDER
These days up North in gardens and along roadsides
often you see a really big, black-and-yellow spider
suspended in the center of a large web with a
conspicuous, white, zigzagging pattern of silk running
vertically and passing beneath the spider. You can see
such a spider over its zigzagging silk at
http://www.backyardnature.net/n/10/100829gs.jpg

That's a female ARGIOPE AURANTIA, so widely spread and
conspicuous at this time of year that it goes by many
English names, including Garden Spider, Writing
Spider, Signature Spider, Banana Spider and Corn
Spider. We have the same critter here, too, for the
species is distributed from southern Canada through
the US, Mexico and Central America.

The circular part of the female's web stretches about
two feet across (60 cm) and the webs themselves
usually are built between two to eight feet high. The
zigzagging pattern of silk, called the stabilimentum,
is variously thought to camouflage the spider or
attract insect prey, but my favorite theory is that
it's mainly to make it easy for birds to see the web
so they won't destroy it by flying through it.

That's a female in the picture, her body minus legs
being about an inch long (2.5 cm). The slender little
brownish males are about a third as large. Males roam
about looking for females and when they find one they
may build their own much smaller web near or actually
within the female's web, then court the female by
plucking strands on her web.

*****

IGUANA IN THE MARIGOLDS
Next to the chair beside the hut's door where I eat
breakfast a dense thicket of marigolds about four feet
high is just beginning to issue flower buds. In about
a month they'll be a pretty sight. As I sit next to
them their sharp, medicinal odor suffuses the
morning's calm, moist air.

Most mornings, within arm's length of where I'm
sitting, an immature Black Iguana perches motionless,
either waiting for prey, watching me, or both. He's at
http://www.backyardnature.net/n/10/100829ig.jpg

Mature Black Iguanas are gray and black, but the
younger they are, the greener.

This particular iguana, about a foot long, has almost
become a pet. On afternoons when sometimes I read in
the door chair he rushes from the general area of the
marigolds and perches atop a rock about six feet away.
If I get up, he doesn't move. In fact, I can walk
right up to him. He's like a dog, but not enough for
me to tickle him.

Of course, iguanas have reptilian brains, not
mammalian ones, so, theoretically, affection and maybe
curiosity shouldn't be part of this critter's
behavioral repertory. But, who really knows what's
going on in that lizard's brain?

*****

MARIGOLD GLANDS
In the above picture, maybe you noticed the many
little bumps near the marigolds' leaflet edges. A
close-up of some leaflets, with backlighting, is at
http://www.backyardnature.net/n/10/100829mg.jpg

Those are glands filled with oils rich in chemicals
that repel certain insects. You've probably read the
advice to liberally plant marigolds in your garden to
help control pests.

Studies have shown that most marigolds also produce
chemical compounds that are toxic or antagonistic to
certain harmful nematodes -- and you may remember that
my entire tomato crop is being wiped out by nematodes.
I don't know if marigold's chemical compounds will
control the specific kind of nematode killing my
tomatoes, but as soon as I have enough seeds from the
marigolds next to my chair I'm going to sow them where
now my tomatoes are dying.

*****

POCHOTE FLOWERING
Biking the quiet little road running south of Pisté to
Yaxuná I saw a tree very similar to the big Ceibas we
often speak of here. Spiny-trunked Ceibas are one of
the largest, most distinctive and appreciated trees of
the humid American tropics. Our Ceiba Page is at
http://www.backyardnature.net/mexnat/ceiba.htm

The tree on the road to Yaxuná, despite growing to about
the same big size as the Ceiba, despite having a very
spiny, thick trunk like a Ceiba, and despite its
leaves being digitately compound with seven or so
leaflets like a Ceiba, definitely wasn't a Ceiba.
Ceiba flower petals are white or pink and about 1-1/3
inches long (3.3 cm). This tree's petals were brown on
the outside and white inside, and were an impressive
4-1/3 inches long (11 cm)! You can see two big
blossoms reaching for the sun at
http://www.backyardnature.net/n/10/100829cb.jpg

One of the tree's digitately compound leaves is at
http://www.backyardnature.net/n/10/100829cc.jpg

A small section of its very spiny trunk is shown at
http://www.backyardnature.net/n/10/100829cd.jpg

The Maya call this tree Piim but in most of Mexico the
Spanish name is Pochote, and I don't think it has a
decent English name. It's CEIBA AESCULIFOLIA -- the
species name aesculifolia meaning "having leaves like
a Horse-chestnut or Buckeye tree." You can see that
Piim or Pochote belongs to the same genus as the
Ceiba, the genus Ceiba, but regular Ceibas are Ceiba
pentandra. In other words, the Ceiba aesculifolia
along the road to Yaxuná is very closely related to
the famous Ceiba, but it's something else.

On our Ceiba page there's a picture of a Ceiba fruit
releasing lots of white, cottony fiber. That fiber
once was sold commercially under the name of kapok,
and before cheap synthetic fibers came along was much
used for stuffing pillows, cushions, life-saving
vests, etc. In the Flora of Yucatan (1947), Paul
Standley reports that in southern Yucatan the Maya
once made large numbers of mantas, or capes, from
Pochote's fruit fibers, and they were regarded as
superior to those of the Ceiba. He also says that
Pochote's fibers were used for starting fire, while
Ceiba's fibers won't easily catch fire.

Pochote's fibers are still in demand nowadays as
stuffing for cushions and such for people with
allergies to wool and feathers.

Pochote, which in rainy tropical lowlands can reach
100 feet tall (30 m), and whose thick trunks often
flair broadly with buttresses, is distributed through
much of humid, lowland Mexico, to Costa Rica. As with
Ceiba, it's a member of the Bombax subfamily of the
Hibiscus Family, the Malvaceae.

*****

STAR-APPLE FLOWERING
Next to the Hacienda's bathroom the big Star-Apple
tree, CHRYSOPHULLUM CAINITO, with its five-inch-long
(13 cm), evergreen leaves -- glossy green above and
silky golden-brown below -- is flowering. Its leaves
and 3/16ths-inch-long (4 mm) flowers are shown at
http://www.backyardnature.net/n/10/100829st.jpg

Besides being a very shapely, fair-sized tree (up to
50 feet, or 15 m) with unusually attractive leaves,
the main thing about Star-Apples is their fruits,
which are apple-sized, spherical, covered with a
smooth purple or light green skin, and contain a
translucent, whitish pulp with 3-8 shining seeds. And
that flesh is very tasty. Star-Apple fruits were
falling about a month ago, but they all hung too high
to photograph, and the ones that fell were all half-
eaten by Kinkajous, so I missed showing them to you.

Still, the current flowers are worth looking at. You
can see one much magnified at
http://www.backyardnature.net/n/10/100829su.jpg

Books say that Star-Apple flowers have five corolla
lobes and stamens but you can see that this one,
picked at random, bears seven of each. In the first
photo you can make out that there's a general mix of
five-lobed, six-lobed and seven-lobed flowers in the
inflorescences. Well, Star-Apples have been cultivated
for a long time and it often happens among cultivars
of long standing that genes get a bit scrambled and
funny things occur -- random spots on cattle, for
instance, and flowers with seven corolla lobes.

Another unusual thing about the blossom shown in the
close-up is that its pollen-producing stamens arise
opposite the corolla lobes, at their bases. Stamens in
most flowers alternate with their corolla lobes. Also,
it's a little unusual for stamens to simply arise from
a corolla wall instead of beneath the ovary.

However, having stamens exactly like these is a
general feature of the family to which Star-Apples
belong, the Sapodilla Family, the Sapotaceae. Other
members of that family include the Chicozapote or
Chicle tree, the Mamey, and Canistel, all trees
producing large, delicious fruits much sought in
tropical markets.

Star-Apples are native tropical American trees planted
widely throughout the Earth's tropics.

*****

ZINNIAS BY THE HUT
Often I sit just outside the hut door reading,
watching the critters, or just looking around. Each
day it's more pleasant there because my springtime
plantings are producing a gardeny feeling.

At http://www.backyardnature.net/n/10/100829hu.jpg
you can see my chair with strawberry-red-flowered
zinnias in the foreground, a tuft of lemongrass just
beyond them, some basil beyond that, then just beyond
the chair and walkingstick is the big clump of
marigolds in which the iguana perches each morning.

The zinnias -- these are Common Zinnias, ZINNIA
ELEGANS -- are reaching their blooming peak about now.
A very red flowerhead three inches across (7.5 cm),
with opposite, stemless leaves arising below is at
http://www.backyardnature.net/n/10/100829zh.jpg

I say flowerhead instead of flower since zinnias are
members of the Composite or Sunflower Family, so
what's shown in the last image is a head consisting of
many packed-together, tiny flowers. If you need to be
refreshed on what composite flowers are like, check
out http://www.backyardnature.net/fl_comps.htm

Now look at the medial section of a zinnia head shown
at http://www.backyardnature.net/n/10/100829zk.jpg

At the top, right corner of that picture what looks
like a golden, upside-down starfish is one of the
head's many disk flowers -- the five starfish arms
being five corolla lobes. Follow the corolla tube down
from the starfish and you'll see that a long, slender
thing shaped a little like a shoehorn partly wraps
around the corolla tube's base. That's a bract, or
modified leaf, separating each flower from the other.
Many kinds of Composite Family flower heads have no
bracts, so their presence here is a feature helping us
know that this as a zinnia. The fact that the bracts'
crimson tops have jagged margins also is notable
because the genus Zinnia embraces 20 or so species,
and the jagged margins help distinguish our species
elegans.

Another feature of zinnias is that their "involucral
bracts" are rounded instead of having the more common
sharp points, plus they overlap one another in several
series instead of standing side-by-side as in many
genera. You can see the zinnias' involucral bracts at
http://www.backyardnature.net/n/10/100829zl.jpg

Some of our zinnias' flowers are long past their
glory, as you can see in the dried, brown bulk shown
at http://www.backyardnature.net/n/10/100829zj.jpg

I've been picking these heads and saving "seeds" from
them, some of which lie in the palm of my hand at
http://www.backyardnature.net/n/10/100829zi.jpg

The best-formed and probably the only fertile "seed"
in that image is the one at the bottom, right.
Immediately above it, the scoop-shaped thing is a
dried involucral bract. I put quotation marks around
seed because the "seed" is actually a special dry,
one-seeded fruit typical of the Composite Family,
known as an achene.

Common Zinnias are native to Mexico, but not to the
Yucatán. They're so loved by gardeners worldwide that
many forms have been developed. There are zinnias with
white, cream, green, yellow, apricot, orange, red,
bronze, crimson, purple, and lilac flowers, those with
striped, speckled and bicolored blossoms, there are
zinnias with double, semi-double and dahlia-like
"pompon" heads, and zinnia forms that range from
dwarfs not exceeding 6 inches tall (15 cm) to those
well over a yard tall (1 m), like mine.

*****

LUSTY PICA-PICA
Maybe you remember from a Newsletter issued around
last Christmas when I introduced you to the vine
called Velvetbean, Pica-Pica in Spanish, famous for
its large legumes being covered with a thick, brown
mat of sharp hairs that can make you itch like crazy.
You can see Pica-Pica and read all about it at
http://www.backyardnature.net/yucatan/mucuna-p.htm

It's way too early for Pica-Pica to be flowering or
fruiting, but it's definitely making its presence
felt, at least to Luis the milpa planter, as shown at
http://www.backyardnature.net/n/10/100829pp.jpg

That picture shows a very discouraged and disgusted
Luis. On Saturday he'd cleaned every weed from the
area he's standing in, but now on Monday morning the
ground is littered with hundreds of vigorous, new
green shoots, and that's Pica-Pica. Before this area
was cleared for the milpa, actually Pica-Pica hadn't
been among the most conspicuous species. However, you
can see that now, if left untended, in a day or two
there'll be a rampant, garden-choking carpet of Pica-
Pica.

Pica-Pica, MUCUNA PRURIENS, is such a tough, vigorous
plant that you just have to admire it -- unless you're
Luis.

By the way, in the background and to the right notice
the low earthen beds framed with rocks and stems of
fallen trees. The Maya call those "eras," and they're
special for this culture. The Yucatán's soil is so
thin and often impoverished that sometimes good soil
must be collected here and there and collected in
"eras" so that plants will have something to root in.
In some places in the Yucatán I've seen people sneak
onto private property at night and rob topsoil,
carrying it home in bags. The Maya here also put such
earthen beds on wooden platforms with legs, and those
structures are called "canchés."

Beyond the eras you can make out Luis's knee-high
corn, among which also are planted squash and beans.

*****

HOES NO, COAS SÍ
The average Northern gardener will see all those
seedling Pica-Picas and immediately think that the
best way to deal with them would be chop them down
with a hoe. Here the hoe is an alien concept.

Apparently there's no word in Maya for the hoe, and
I've seen myself that if you use the Spanish word for
hoe, azadón, they'll never have heard of it. You can
see how Luis deals with weeds without a hoe at
http://www.backyardnature.net/n/10/100829ko.jpg

Luis's implement, rather like a short machete with a
curved pointed tip, is known as a coa in Maya, and
every Maya man who works with the land has one, as
well as a machete. You can get a better look at a coa
at http://www.backyardnature.net/n/10/100829kp.jpg

For me, the advantage of a hoe over a coa or machete
when used for something like cutting down all those
Pica-Pica seedlings is that you don't have squat or
bend over. However, when I explain the concept to the
Maya, usually drawing a hoe on the ground with a
stick, the skepticism on people's faces is clear.

Hoes are just another instance of gringos using
something complex to accomplish what a simple machete
or coa can do so easily. I've seen men spend long,
long days squatting with their coas, waddling across
the ground they clear like legless ducks, doing what I
figure a hoe could accomplish much faster and much
less painfully.

*****

ON THE BEAUTY OF RAISING HELL
The human species became Earth's most dynamic lifeform
by outcompeting other species. Our brains enabled us
to outthink the species we hunted, and to domesticate
other animal and plant species. Our ancestors
struggled for dominance aggressively, self-servingly
and piteously. Had a race of flower-sniffing,
nonviolent vegetarians like me mutated into existence,
we wouldn't have lasted long; instantly we'd have
succumbed to neighboring clans coveting what we had,
and maybe wanting to eat us.

With humanity's evolutionary history, it's amazing
that on the average today we're such a docile,
peaceable species. Only occasionally, as when we're
under stress or experiencing mass hysteria, does our
aggressiveness break out.

That's not saying that we're all just waiting to tear
one another apart. Our instincts for aggression are
strong, but our social programming is stronger. Also,
I believe that once the Sixth Miracle of Nature enters
one's life -- the Miracle of inspired thinking,
feeling and behaving beyond mere instinct-driven
impulses -- there's something new in a being's life,
maybe something not yet named (unless it's "love-for-
all-things"), that's even stronger.

Since we all have this inborn urge to raise hell, it's
worth thinking systematically about the matter.

To my mind, hell raising by definition is shocking and
disruptive. Therefore, drunken or drug-induced
behavior, reckless driving, public cursing -- none of
that is hell raising because it's so commonplace and
therefore not shocking. Society even gives a wink and
a smile to such behaviors through its mass marketing
and entertainment.

When Beethoven wrote his Ninth Symphony with that
final movement the most stirring and revolutionary in
all music history, that was raising hell.

When a spontaneous mutation occurs in a species and a
new feature arises to be passed on to future
generations, that's Nature raising hell, shockingly
and disruptively foregoing the usual step-by-step
approach, willing to gamble with life while knowing
that probably the mutation will be maladaptive or even
lethal, but just possibly it might be something grand.

A form of hell raising that's particularly pretty to
me is when somebody challenges and refuses to go along
with humanity's comfortable, established but
biosphere-shattering and Life-On-Earth-threatening
traditions and agreed-on social mindsets and
behaviors.

In fact, the most beautiful forms of hell raising are
those arising when one thinks and thinks, and feels
and feels, and loves and loves, and in doing so gets
so mad that he or she actually does something creative
and decisive in response. Maybe something like wearing
lighter clothing when it's hot, or just putting up
with the heat, instead of using an air conditioner.

That's shocking or at least weird to "normal behaving
people," and it's certainly disruptive to society's
dominant power structures and vested interests, and it
really is beautiful.

*****

Best wishes to all Newsletter Readers.

Jim

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