March 22, 2019

THREE GRASS FUGUES
Though this week we've enjoyed three or so light showers, late March in the Yucatan is always very hot and dry. Last week it was windy, too, the wind like hot air from a hair drier. The woods with its dry-season-leafless trees and scorched-brown herbaceous layer looks wintry to a northerner, even as the heat and dusty air say otherwise.

It's an austere, almost hostile season for living things. Along with drought-killed vegetation and all the plants that have gone into leafless suspended animation, animals also keep a low profile, birds perched in shadows most of the day, often panting with their beaks open, just looking around. Most reptiles and amphibians either are estivating (summer equivalent of winter hibernating) in the ground or leaf litter. Invertebrates may do the same, or simply die, for the continuance of their species leaving behind eggs awaiting the rains.

My own focus on this world shifts to accommodate such changes. Nowadays I've slowed down and contracted, like a toad spending most of the time in his hole, but sometimes coming outside to look closely at close-lying things. It's like abandoning the mood for lush symphonies in grand concert halls, but now hankering instead for elegant fugues played starkly on a simple harpsichord.

Like this, you notice grasses. Grasses are fugues, nothing lush about them, everything about them refined to the barest elements, and submitted for inspection clearly and distinctly. Nowadays, I like grass-looking just as earlier I sought gaudy orchids in secret lushness.

This helps explain why this week I start off with three grasses, each a different fugue on a hot, dry, windy day, each offering details worthy of noticing, and savoring.

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SPRANGLETOP GRASS
In the garden, growing amid my lush bed of daily-watered mustard greens, a distinctive grass was flowering. You can see its many tiny flowers, or spikelets, arrayed in a large, diffuse panicle at https://www.backyardnature.net/n/19/190322lc.jpg

Arrayed along the panicle's terminal segments, the spikelets were unusually small, the less mature ones only about 2mm long, as shown at https://www.backyardnature.net/n/19/190322ld.jpg

More mature spikelets were a little longer, and with them it was more obvious that each spikelet contained two or more florets, as a picture of two spikelets, each with two florets, shows at https://www.backyardnature.net/n/19/190322lf.jpg

These features and some others led me to the genus Leptochloa, but to figure out which species of Leptochloa it was, I had to see what's on display at https://www.backyardnature.net/n/19/190322lg.jpg

The upward pointing, white, papery, jagged-topped item at the top is the ligule, just like Leptochloa is supposed to have, but of the several Leptochloa species listed for the Yucatan, only one bears leaves whose sheathes produce such long, white hairs as this one, and that's LEPTOCHLOA PANICEA. Leptochloa panicea occurs in the tropics, subtropics and warm-temperate zones nearly worldwide. With such a great distribution area, this is a very variable, or "polymorphic," species. Currently three subspecies are recognized, ours being ssp. mucronata.

Up in Texas we've met another Leptochloa species, Leptochloa dubia, which you might enjoy comparing with the present one, because of the "variation on a theme" thing. Our Texas Leptochloa resides at https://www.backyardnature.net/n/h/sprangle.htm

Up there we learned to use the English name "sprangletop" for members of the genus Leptochloa, "sprangle" meaning -- at least in parts of the US -- spread-out, like our grass's flowers. Our current Leptochloa panicea doesn't seem to have a good English name, but I find some authors referring to it as Sprangletop, so that's how I think of it.

In the Yucatan Leptochloa panicea is described as flowering and fruiting during the rainy season from June to September. Our flowering plant can be excused from the rule because my wonderful mustard greens get watered every day, creating a rainy-season microclimate.

This is the first time I've noticed Leptochloa panicea and I don't believe it's very common here. Maybe it got planted in the garden when I sowed my mustard greens. The species isn't particularly favored as a pasture grass. Mainly people just think of it as a weed, despite its handsome panicle of widely dispersed, tiny flowers, and the pleasure small seed-eating animals must have feeding on its plentiful tiny seeds.

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CORAL PASPALUM GRASS
At the weedy edge of a semi-abandoned, irregularly watered papaya planting, beside a limestone rock, there grew a grass so enmeshed in the clutter of its disrupted environment that even looking at it you hardly saw it, as you can believe with the picture at https://www.backyardnature.net/n/19/190322p5.jpg

In that image, notice that the grass's leaves in the picture's bottom half are robust and stiff, looking very perky for such a hot, dry time. At the picture's top, right, the grass's flowering head is so modest it's almost invisible. A picture showing that it consists of four narrow, spike-like branches well separated from one another displays the flowering head better at https://www.backyardnature.net/n/19/190322p6.jpg

The spike-like branches show more character if you look at them closely, as is done at https://www.backyardnature.net/n/19/190322p8.jpg

The branch axis, or rachilla, becomes sinuous toward its tip. The rachilla itself is somewhat flattened, only about 0.7mm wide, and is tipped with a hairy spikelet. Lower down the rachilla, a few spikelets already have fallen off, leaving short, forward-pointing stems, or pedicels. Also, notice that all the spikelets arise on just one side of the rachilla. Among this grass's most telling field marks are two appearing at https://www.backyardnature.net/n/19/190322p7.jpg

First, the spikelets are exceptionally tiny, only about 1mm long (1/32inch). Also, in that picture, notice that the spikelet stems, or pedicels, arise in pairs. It's also worthwhile to pay attention to the white tuft of hairs at the base of each branch, shown at https://www.backyardnature.net/n/19/190322p9.jpg

These details and others pointed us to PASPALUM BLODGETTII, which the online Flora of North America for some reason calls Coral Paspalum. Paspalum blodgettii is granted an English name because it occurs in southern Florida as well as the Caribbean, the Yucatan Peninsula and Belize.

This is another species that normally blossoms during the rainy season, June through September, so apparently our March-blossoming plants appear because of occasional watering.

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PARÁ GRASS
Along the highway to Timozón, all along the pavement one of the most commonly occurring grassy weeds entangles so promiscuously with surrounding vegetation that at this season you just see modestly arrayed flowering heads rising above the weedy clutter atop knee high stiff, slender stems, as shown at https://www.backyardnature.net/n/19/190322uh.jpg

The lush greenness in that picture is in stark contrast to the nearby woods and fallow cornfields, which are scorched brown here in the late dry season. I think this roadside greenness is possible because water from our rare showers runs off the asphalt, giving the near roadside extra watering. Also, these weeds are just tough, adaptable beings putting up a good fight in an extreme environment. Whatever the case, our roadside grass's head consisting of three spike-like branches with all their spikelets arising from just one side of their branch axis, or rachilla, is shown more clearly at https://www.backyardnature.net/n/19/190322ui.jpg

Those narrow, stiff, spike-like branches are similar to what was seen on the Paspalum just looked at. In fact, I kept thinking we had another Paspalum species as I took the following pictures. First, look at the grass's Paspalum-like spikelets at the peak of their sexual activity, at https://www.backyardnature.net/n/19/190322uj.jpg

The dangling, yellow, banana-like items are the stamens' anthers. Notice that the anther at the right has a hole at its bottom, where pollen dribbles out. Above the anthers, the dark purple, feathery items are stigmas, the pollen-receiving part of a pistil. The stigmas' broad featheriness provides plenty of surface area for catching air-borne pollen. Other very important identification features are shown at https://www.backyardnature.net/n/19/190322ul.jpg

As with the previous Paspalum species, besides the spikelets lining up on one side of the rachilla, and the rachilla being somewhat flattened and narrow, the big fieldmark is that the spikelets are about 4mm long (3/16th inch). Theypre longer than almost any Paspalum spikelet, so at this point the Paspalum idea starts getting shaky. A ligule with its associated stem node is shown at https://www.backyardnature.net/n/19/190322uk.jpg

The ligule consists of a jagged-topped, short-hairy membrane split to the bottom here and there. Also note that the stem's node area bears long stiff hairs, which thin out both above and below. And, the sheath and leaf's undersurface are both practically hairless. These seem like gnat-picking details, but they're important for identification.

All these features led me to UROCHLOA MUTICA, thought to be native to northern and central Africa and parts of the Middle East, but now an invasive species throughout much of the rest of the world's tropics, subtropics and warmer Temperate Zones, including Florida and Hawaii in the US. Urochloa mutica goes by many English names, but the one seeming to be catching on most is Pará Grass. One reason for its vast distribution is that it's often planted as fodder and as pasture grass.

We met our first Urochloa species up in Texas, where one name for it was Signalgrass. You may enjoy comparing the details of that Texas species with the current one -- the "variation on a theme" thing -- by visiting https://www.backyardnature.net/n/h/urochloa.htm

I read that some Urochloa species so closely resemble species in either the genus Panicum or Paspalum that at times they have been placed in those genera. I'm not the only one who can confuse these look-alike species. However, even being confused by them and having to look closer and closer at them, I get from them what I want.

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STORED CARROTS DEVELOPING BLACK SPLOTCHES
By the time the fruterías in our backcountry area receive their fruits and vegetables for sale, normally the products have been on a long journey, for the Yucatan is too arid and the soil too abused to produce much here. Often by the time our fruits and vegetables hit the display stand, they look less than fresh. For example, nearly all the carrots I buy locally are blemished with black splotches such as those shown at https://www.backyardnature.net/n/19/190322ct.jpg

This week it occurred to me that the splotches probably are caused by a fungus, that the fungus species would have a life history, and that it might be interesting to know more about it. Especially I wondered whether eating carrots from which the splotches haven't been completely removed might be bad for the health.

Best I can tell, the splotches are known in the carrot-selling world as Black Root Rot, described as a blackening that often is circular in outline, is superficial, and has a sooty appearance. Two fungus species may cause it: Thielaviopsis basicola and Chalaropsis thielavioides.

Both these species occur naturally in the soil. When carrots are wounded during the harvest, the fungi enter through wounds and abrasions. The black spots develop on carrots stored at room temperature and high humidity. They often develop on carrots stored in plastic bags from which moisture can't escape.

Thielaviopsis basicola is a member of the Ascomycota fungus phylum, along with molds, mildews, the edible mushroom known as the Morel, and other lesser known kinds of fungus. The species, besides infecting carrots, attacks many other kinds of plants, including petunias, snapdragons, sweet peas, verbenas and violets. In those plants the leaves and root system become stunted when contaminated, plus their leaves yellow between the veins and their branches may die back. Chalaropsis thielavioides seems to be much less studied than Thielaviopsis basicola, but probably behaves similarly.

During my information search no mention at all was found about the toxicity of carrots with black splotches. That suggests that it's not an important issue. Still, I'm going to continue cleaning my carrots. I just won't worry too much if a few black specks make it past me.

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GUIANA CHESTNUT
I first met the Guiana Chestnut tree on November 20th, 1996. I know the date because I was keeping notes for my book A Birding Trip through Mexico," available online at https://www.backyardnature.net/mexbirds/ Late that day I'd reached the banks of Laguna Catemaco, a large, beautiful lake in southeastern Veracruz state. I erected my tent on the lake's bank, then sat down to watch the Sun set over the lake. And between the Sun and me, my first Guiana Chestnut was growing in shallow water about 50ft out. Herons were gathering in it to roost for the night. I sketched the scene and later did some artsy Photoshop work on it, and that's shown at https://www.backyardnature.net/mexbirds/catemaca.gif.

Therefore, last October 5th as I was hiking the road from Palenque National Park to the town of Palenque, Chiapas, even though the trees were arrayed with huge, gorgeous blossoms, it was almost a disappointment to find a whole row of planted Guiana Chestnuts tamely lined up along the tourist walk. Needless to say, no roosting herons were gathering in them, and no lush garden of ferns, lichens, mosses, bromeliads, orchids, anthuriums and arboreal cacti mantled their branches.

Even so, I was glad to see a fully open flower hanging so low that I could press my nose into it and feel its long, pink stamens tickling my face. You can see flower at https://www.backyardnature.net/n/19/190322pp.jpg

In that picture the three green, erect, cigar-shaped items at the blossom's left are unopened flower buds. To the left of my hand is a typical "digitally compound" Guiana Chestnut leaf, its several leaflets uniting at their bases like the "digits" of a hand coming together at the palm.

Our flowering Chiapas tree also bore large, capsular-type, brown, woody fruits, as shown at https://www.backyardnature.net/n/19/190322pq.jpg

Some of those fruits had burst open, leaving seeds lying on the ground, seen at https://www.backyardnature.net/n/19/190322pr.jpg

Each Guiana Chestnut fruit is divided into five compartments, and in each compartment several seeds are squeezed together in a package of brown, papery tissue. In the above picture you see three seed clusters, the cluster at the upper, right broken apart to reveal individual seeds. The seeds taste somewhat like European chestnuts and can be eaten raw, roasted, or ground into flour for making bread or a nourishing drink. Even the tree's leaves and flowers are edible.

The tasty seeds explain the "chestnut" in the name Guiana Chestnuts. The species is also known by such names as Malabar Chestnut, French Peanut, and Provision Tree. Sometimes it's sold commercially under the name of Money Tree or Money Plant, because in Asia it's often planted in the hope that it'll bring prosperity. But, the whole world knows the tree as PACHIRA AQUATICA, and when you look up that name you see that it's native from Mexico south through Central America to Colombia.

Despite the Guiana Chestnut's history of provisioning people with nutty seeds, there's some evidence that the nuts shouldn't be eaten by humans, since they contain cyclopropenoid fatty acids, which some say is carcinogenic. Of six laboratory rats fed on the nuts, five died and the remaining one developed serious health issues, according to a 2008 publication by Hanus and others.

In Mexico, the plant has been used in traditional medicine for many cures, ranging from asthma and diabetes, to skin problems and dysentery, as well as to "purify the blood," and to ward off "bad air" that mysteriously comes around at certain hours of the night.

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MEDITATION
Sometimes it's easy to decide that all is lost, or at least humanity as we know it is lost, maybe even that the human species is simply unfit for sharing planet Earth with other life forms. Lately I've seen a glimmer of hope, in the form of several volunteers from Canada and the US who stayed for awhile at Genesis Resort in Ek Balam, or on the off-grid rancho where I stay.

I know that when someone decides to do service in backcountry Yucatan they've passed through several filters, so our volunteers are not representative of the general population. For instance, during all the garden tours I've conducted here and previously at Chichén Itzá, I never had a single North American Trump supporter, or among the many British visitors, a Brexit supporter.

Thing is, all the young volunteers I've met, and most of the older ones, meditated. Apparently, up north meditation is catching on. One volunteer even said that in certain places meditation is seen as "cool," and has become a fad. Still, the meditators I've met were serious, and all said they'd benefited from it greatly, even profoundly.

A middle-aged lady told me that she stumbled onto meditation accidentally, when during a time of boredom she took a class just because it was offered down the street and was something to do.

"Now I'm seeing that so much of what people around me say and do -- as well as what I used to say and do -- is pointless, and a waste of opportunity for experiencing life more fully," she told me. "Even my general health has improved. I feel reborn, and every day look forward to developing my meditation skills more."

An initial hurdle to learning about meditation is that the practice comes in many forms and contexts. Our feelings about it may be influenced by negative opinions we have about certain philosophies or religions that practice it. A good introduction to the many-sided world of meditation is provided by Wikipedia at https://en.wikipedia.org/wiki/Meditation

Here's the general definition of meditation found on that page: