JIM CONRAD'S
NATURALIST NEWSLETTER
Issued from Hacienda Chichen Resort
adjoining Chichén Itzá Ruins in
YUCATÁN, MÉXICO

September 12, 2010

NECTAR PROVIDERS PASSING THE TORCH
In July and early August a certain high-climbing, square-stemmed liana, or woody vine, bore conspicuous clumps of 1½-inch long (3.8 cm), purple blossoms. The vine was a member of the Trumpet Creeper Family, the Bignoniaceae, and its flowers were shaped like those of the North's Trumpet Creepers. The plant was Cydista potosina, and you can see and read all about it at http://www.backyardnature.net/yucatan/cydista.htm.

As August wore on I expected those high-hanging purple flowers to slowly disappear from the landscape, but they didn't. In fact, as September began, an even more eye-catching flush of purple flowers on high-climbing lianas began appearing. It was a second species of Cydista.

It was a beautiful case of a species taking over the job of supplying pollen and nectar to a certain size and kind of pollinator as the previous species' flowering period gradually ended. You might enjoy seeing if you can distinguish between Cydista potosina at the last link, and the species flowering now, shown at http://www.backyardnature.net/n/10/100912cd.jpg.

A close-up of one of the new species' flowers is shown at http://www.backyardnature.net/n/10/100912ce.jpg.

I'll bet you can't see any significant differences between them. In those two pictures I can't, either. An important clue that we have a second species, though, is shown in the stem close-up shown at http://www.backyardnature.net/n/10/100912cf.jpg.

On the picture's right the squared stem slants upward. The petioles of two compound leaves connect with the stem above my middle finger. The clue that we have a new species is the leafy, ear-shaped items at the base of each petiole. Those are stipules, or modified leaves, which some species have but others don't. On Cydista potosina similar stipules are produced on young shoots, but those stipules soon fall off. On this second species flowering now, the stipules remain on old stems.

A close-up of the stipules better showing the squared stems, which actually are sharply "winged," is shown at http://www.backyardnature.net/n/10/100912cg.jpg.

The top picture on the C. potosina page shows older stems clearly lacking those stipules.

So, this second species is CYDISTA DIVERSIFOLIA, and it's very closely related to the earlier flowering Cydista potosina. Except for the stipules and the different flowering periods, I don't think I could tell the two species apart. Maybe by the fruits, but we don't have fruits yet. Also maybe C. diversifolia's stems are more sharply angled than C. potosina's, and my impression is that C. diversifolia tends to live in drier soils than C. potosina.

Both these Cydista species are used locally for weaving traditional Maya baskets. In certain areas both species have completely disappeared because of overharvesting for basket weaving.

Cydista diversifolia occurs from southern Mexico and the Yucatán south through most of the drier forests of Central America.

*****

MARIGOLDS
You'd be surprised how few plants are flowering now during the heart of the rainy season. It seems that a blooming flush occurs at the end of the dry season, around April, then another toward the end of the rainy season, around November. Nowadays a few weedy, yellow- blossomed Composites (Sunflower or Aster Family) are coming online, but otherwise mostly there's just a lot of lush, rainy-season greenness out there.

Maybe that's the reason I'm enjoying the marigolds -- also yellow-flowered composites -- planted beside the hut's door. As I sit there reading and looking around, I just can't keep my eyes off their frilly, orangish blossoms, so vivid against dark green foliage behind them or, better yet, against the blue sky beyond. A typical flowerhead with a summery sky beyond is shown at http://www.backyardnature.net/n/10/100912mg.jpg.

Besides drinking in the sheer, gorgeous colors, there are textures and pleasing designs to dwell on. Since we're dealing with composite flowers here, what's shown in the photo is a flowerhead composed of many individual flowers. Marigold flowerheads bear two types of flowers, tubular disk flowers and flat ray flowers. A diagram distinguishing the two types is at http://www.backyardnature.net/marigold.jpg.

A photo showing a ray flower (on the left) and a disk flower (on the right) on the palm of my hand is shown at http://www.backyardnature.net/n/10/100912mh.jpg.

The flowerheads of some Composite Family genera bear only ray flowers (Dandelion and Chicory). Other genera bear only disk flowers (Eupatorium and Ageratum). The flowerheads of Marigolds (as with asters, sunflowers and zinnias) bear both kinds.

The enormous Composite Family embraces maybe 1500-1700 genera and 20,000-25,000 species, and the pollen- producing stamens of the flowers in each of those 20,000-25,000 species do something interesting that people seldom notice because the stamens are so small. You can see what they do in a marigold disk flower at http://www.backyardnature.net/n/10/100912mi.jpg.

In that picture the disk flower's tubular corolla has been split and pulled to the right. The Y-shaped item at the top is two fuzzy stigmas, which are the female part of the pistil where pollen germinates. The five stamens doing their interesting thing lie just below the projecting stigmas. What they're doing is fusing their anthers into a cylinder surrounding the ovary's style. The style is the "neck" connecting the ovary with its stigmas. Anthers are baglike parts of the stamen that split open to release pollen. Among the thousands of Composite Family species there's mind- boggling variation, yet always the flowers' four or five stamens join at their anthers to form a tube around the style.

A very important feature helping distinguish marigolds from other composite flower types is shown at http://www.backyardnature.net/n/10/100912mj.jpg.

On the left, look at the green, goblet-shaped item from which the disk and ray flowers emerge. That's the involucre. In the vast majority of composite flower types the involucre is composed of two or more series of more or less triangular, sharp-tipped, separate scales or "involucral bracts." You can see that in marigolds the triangular scales are long and slender, there's just one row of them instead of two or more, and they are joined at their margins. A couple of weeks ago we looked at a Zinnia's involucre, which had four or so series of overlapping bracts not joined together at their margins. You can see that again at http://www.backyardnature.net/n/10/100829zl.jpg.

If you've forgotten what a marigold's pinnately compound leaves with oblong or lanceolate, serrate segments look like, you can see one at http://www.backyardnature.net/n/10/100912mk.jpg.

My marigolds, nearly five feet tall (1.5 m), are much larger than those I've seen up North. Their blossoms average about two inches across (5 cm). In garden catalogs this native Mexican species planted worldwide is marketed as the Big, Aztec or African Marigold. It's TAGETES ERECTA. The "African Marigold" name derives from a time when everyone didn't know that it really is from good old Mexico.

*****

"PILGRIM" IN RED
Once again biking Pisté's backstreets has paid off in terms on discovering a gorgeous plant completely new to me. This time it was a streetside bushy tree about 15 feet tall (4.5 m) with alternate, ovate leaves, and with the inch-wide (2.5 cm), red flowers shown at http://www.backyardnature.net/n/10/100912jp.jpg.

What was encountered inside each blossom was surprising and beautiful, and you can see it yourself at http://www.backyardnature.net/n/10/100912jq.jpg.

Those are ten stamens with their matchstick-like filaments joined into a column, almost as in the Hibiscus Family. Each stamen is topped by a long anther splitting along both its edges to release yellow pollen. Another striking feature of the flower is that there's no hint of female parts -- no pistil with its stigma, style and ovary. This is a unisexual male flower.

Examining a leaf, where the blade attached to its petiole, there were stalked glands shown at http://www.backyardnature.net/n/10/100912jr.jpg.

Unisexual flowers, glandular herbage and more-than-normal juice exuding from the wound where the leaf broke of... and already I was getting an idea of which plant family the tree probably belonged too: Surely it was the Euphorbia Family, the Euphorbiaceae, in which also are found Poinsettias, Castor Bean, and Manioc.

By using the thumbnail image feature of Google and searching on the keywords "Euphorbiaceae red flowers," it wasn't long before I found a match. The pretty tree in Pisté is known to the English speaking world as Peregrina, Spicy Jatropha, and other names. In Spanish "peregrina" is the feminine form of the word "pilgrim." It's JATROPHA INTEGERRIMA, a native of the West Indies, and especially well known in Cuba.

At first I was uncertain about the ID because many images of the species on the Internet show leaves with very different shapes. Finally I read that the leaves are extremely variable, ranging in shape from oval to elliptic, to even longish and fiddle-shaped. Also, all the leaves in my picture are unlobed, but larger leaves on older branches sometimes bore three low, sharp-pointed lobes.

In southern Florida Peregrina has escaped from cultivation so now it even grows in the US. Many Internet pictures of the tree have been taken in Hawaii so it must be a favorite garden plant there, too.

*****

REALLY BIG AVOCADOS
As if spotting the Peregrina during my most recent biking through Pisté weren't enough, that same day I saw the really big avocado on a streetside tree shown at http://www.backyardnature.net/n/10/100912av.jpg.

I could only see three fruits, and all were so high up I couldn't measure them. However, an Avocado tree leaf is about four inches long (10 cm) and the fruit seems about twice as long as an average leaf, so that avocado fruit must be around eight inches long, which qualifies it as a very big avocado.

I thought that maybe I'd found a rare cultivar only grown in Maya territory, but my Maya friends say that it's nothing special, just one of several avocado cultivars planted everywhere in the tropics. That information is confirmed on such Internet pages as one at http://avocadopoint.com/avocados/Avocado+Cultivars/.

That page describes several cultivars, and a number are mentioned as producing very large fruits. If I had to guess which cultivar is shown in the picture I'd say "Fuerte," but that's only because it matches pictures of that fruit, and "Fuerte" is a fairly commonly grown type.

Avocados are native Mexican plants, and Mexico is by far the world's greatest exporter of them. You might enjoy reading about the history of avocado production at http://whatscookingamerica.net/avacado.htm.

If you have an Avocado tree and want to try to identify which cultivar it is, a helpful piece of information is that among Avocados there are two flowering types: "A" and "B". "A" cultivar flowers open as female on the morning of the first day and close in late morning or early afternoon. Then they open as male in the afternoon of the second day. "B" varieties open as female on the afternoon of the first day, close in late afternoon and reopen as male the following morning. Once you know whether you have an "A" or "B" type, you can rule out about half the cultivars.

*****

MORA SAWDUST
I'd been helping Luis pull Picapica vines from his milpa, or cornfield, and as I was leaving the milpa area I came onto a spot where Luis had felled a dead tree to make way for more milpa. What I saw is shown at http://www.backyardnature.net/n/10/100912ma.jpg.

What's interesting is that the sawdust is so orange. It makes sense, however, since the tree was a Mora, MACLURA TINCTORIA, of the Fig Family. We've already met this tree flowering and fruiting. The resulting web page with pictures and discussion is at http://www.backyardnature.net/yucatan/mora.htm.

On that page I write, "Once Moras were highly regarded because their wood produces a bright, yellow dye. During World War II Mora contributed to the Allied cause by producing a dye used to color soldiers' khaki uniforms. Its commercial name was Fustic."

Elsewhere I write that "Mora woodchips soaked in water produce a yellow dye, and this dye has long been used by the Maya. Certain metals can be added to the soaking water to produce a green dye."

I collected some sawdust and soaked it in water overnight. The result is shown at http://www.backyardnature.net/n/10/100912mb.jpg.

*****

SUNBURNED LEAVES
Last week we saw that many Maya believe that rain falling during our current rainy-season afternoon storms burns the plants it falls on. I'm skeptical about that, but I know for a fact that leaves can suffer serious burn from the sun.

We have many potted Royal Palm seedlings growing in deep shade. They need to be moved into sunlight bit by bit, so the other day I moved some to a sunnier spot but misjudged how much sunlight they'd get. The resulting white "killed areas" -- where the blades' bent surfaces faced directly against the sun -- appear at http://www.backyardnature.net/n/10/100912su.jpg.

The same happened with a Ramon tree. Its sunburned leaf with blotches of dead and dying tissue is seen at http://www.backyardnature.net/n/10/100912sv.jpg.

The Ramon leaf is interesting because when I moved the seedling the leaf was just unfolding leaf a top the seedling's stem. Leaves below it didn't suffer, apparently because they'd been hardened enough over time. Leaves developing later above the damaged leaf didn't suffer either, because as they unfolded they could adjust their defenses to the increased sunlight. Clearly, Ramon saplings can accommodate a range of sunlight intensities, but at least their young leaves are vulnerable to sudden changes.

*****

WIND
A funny thing happened on the way to nirvana. As if it were the road to quantum mechanics, halfway there the rules changed, the map begun with proved all wrong, and I even lost track of who it was, exactly, doing the traveling, and why.

Nirvana, eventually it became apparent during many years of seeking it, is no sudden epiphany, or newfound ability to tap into mysterious powers or insights. My opinion is that the nirvana-seeking process is long and slow, with many setbacks along the way. Nirvana gradually reveals itself as the state of mind in which one identifies with the unity of all things so completely that -- at least in brief flashes of insight -- one discovers his or her own apartness, or isolation, to be pure illusion.

Lots of people have figured this out, and I'm not sure I'd have ever realized it if I hadn't been exposed to the idea from several sources. Some write about the insight in books or songs, others talk about it with their friends, but I think most just keep their mouths shut, knowing that even once the insight is achieved there's not much you can do about it. No matter how well you understand, you still end up as a spiritual awareness stuck inside an animal body that's slowly wearing out.

How I love the wind. Funny, but while thinking about all this a wave of intense nostalgia washes over me, and that's the thing I wish to say. Maybe it's because as I write this, the wind scoots pretty, white cumulus clouds across a blue sky, the wind shakes green bushes visible through the openings of the hut's pole walls, the wind carries to me the Melodious Blackbirds' liquid calls, and the motmots' funny, croaky one, and the odor of rich mud from yesterday's rain, and of moldering herbage, odors so redolent of life and process and, it seems to me, unity.

I'd like to be the wind, to flow in a vast, moist wave off the Caribbean bestowing fragrance of salt and fish onto Cancún then over Pisté and Chichén Itzá absorbing odors of mud, of flowering acacia, woodsmoke, and baking tortillas from a world of Maya huts.

And the beautiful thing is that to the extent my mind truly embraces the nirvanic insight of unity, I AM the wind bestowing, absorbing, flowing on and on.

*****

Best wishes to all Newsletter readers,

Jim

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