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

January 2, 2011

OUT-OF-HABITAT THRUSH
As I returned a wheelbarrow to the shop, movement atop the hill caught my eye. You can see what it was at http://www.backyardnature.net/n/11/110102wt.jpg.

It was a very familiar old friend from forested eastern North America, the Wood Thrush, CATHARUS MUSTELINUS, and I was especially happy to see him because this species' numbers have diminished by about half from when I was a young birder. However, it was jarring to see this particular bird where he was. For, Wood Thrushes are quintessential denizens of moist, shady, well developed forest, but here this bird was hopping about on a barren, sun- and wind-swept, highly eroded hill crest that not long ago had been a cow pasture.

Moreover, Howell's distribution map for the species shows the northern limit of its winter distribution to be a bit south of here, with its presence here in the more arid north expected only during migration.

What I'm hoping is that Wood Thrushes are proving flexible enough in their habitat requirements that they can start surviving in other than their usual moist, shaded, more or less intact forests. Maybe this individual atop our barren hill has genes adapted for the new world to come, and he'll be a pioneer for future Wood Thrushes in habitats very different from their traditional ones.

But, what would it feel like to hear the Wood Thrush's rich, fluty, echoic call floating across a scorching, scrubby barren?

*****

JUVENILE PAINTED BUNTING
Last week we posted the gorgeous male Painted Bunting at http://www.backyardnature.net/n/b/painted.htm.

This week, also in the little plastic trough in front of the hut, a juvenile came to take a bath. You can see how drastically different the juvenile looks at http://www.backyardnature.net/n/11/110102pb.jpg.

Juveniles are very similar to females of the species. I know that this is a juvenile because Howell says that the juvenile's underparts often bear indistinct, dusky streaks, and this individual's streaked chest is apparent. Also the juvenile's underparts are described as "washed pale buffy brown" while those of females are yellowish -- and this one's breast is brownish.

Especially in brilliant morning sunlight the upper parts of both females and juvenile birds show up strikingly greenish. In the picture, that white spot below the bird's nape must just be an anomalous white feather.

*****

SUNFLOWER GOLDENEYES IN SUN AND WIND
Hiking to Pisté to buy bananas and oranges I decided to check out an abandoned field along the way. Back in college I had a special interest in "old field succession" -- how distinct communities of plants successively displace one another between when a field is abandoned and when it reverts to a secondary woods. This time last year the Pisté field had been covered with knee-high annual herbs and grass, so what would it look like this year?

The change was striking. The most conspicuous plant, in some places forming house-size thickets, was a bushy, eight-ft-high (2.4m) member of the Composite or Sunflower Family absolutely loaded with inch-wide (2.5cm), yellow blossoms. It was a dazzlingly sunny day with a stiff breeze, and how pretty it was to stand beside the plants watching their golden heads heave in the wind. You can see a small part of a plant at http://www.backyardnature.net/n/11/110102vg.jpg.

The other day a visiting botanist told me that the Yucatán's composites -- plants in the Composite or Sunflower Family -- were driving her crazy, since there are no field guides or identification keys for them. One reason the Composite Family is such a challenge is that there are so many of them. In the adjacent state of Quintana Roo about 90 species in the family have been listed, and there must be a similar number here. In Quintana Roo the Composite Family is the third most diverse family, after the Bean Family (±146 species) and the Grass Family (±101 species).

Composites are a problem for me, too, but that day I decided to try on this spectacular species.

Keeping in mind the key field marks distinguishing genera and species in the Composite Family, I systematically noted the yellow-flowered bush's features. First I looked beneath the flower head and saw that the green scales, or phyllaries, overlapped one another in three or so series, and were expanded at their bases and with sharp, herbaceous tips, shown at http://www.backyardnature.net/n/11/110102vh.jpg.

Next I broke apart a flower head to see if individual flowers inside the head were separated from one another by scales (also called bracts or paleae). I found many unusually wide, sharp pointed ones, shown at http://www.backyardnature.net/n/11/110102vi.jpg.

Next I needed to know what kind of "pappus," if any, crowned the plant's one-seeded, seedlike achene-fruits. Pappi on mature achenes eventually mature into fuzzy, wind-catching parachutes, spines that stick into fur, or several other configurations, all designed to help the fruit get disseminated. You can see what I found atop three achenes at http://www.backyardnature.net/n/11/110102vj.jpg.

Each achene bore a pappus in a different state or repair. The pappus of the one on the left is complete, consisting of two long, sharp, broad-based spines, plus a crown of four or so jagged-topped (lacerate) scales, and these surround the old, drying-up disk- flower about ready to fall off. On the middle achene the flower and one long, sharp spine have fallen off. On the achene at the right just the crown of four or so lacerate scales remains. Maybe these sharp-pointed scales help the achenes stick to passing animals.

Finally I looked at the leaves, and one is shown at http://www.backyardnature.net/n/11/110102vk.jpg.

The leaves are conspicuously three-nerved from their bases, plus their blades form "wings" extending part of the way down the petioles. Leaves on the plant were all "alternate" -- one leaf per stem node -- but scars on the stem at the plant's base indicated that the first leaves may have been "opposite" -- two leaves per stem node.

With these field marks noted and documented I was able to get a name, thanks especially to the fact that the species also occurs in the US's southwestern desert, so the species is keyed out and described in the online Flora of North America.

Among the plant's English names are Sunflower Goldeneye and Toothleaf. It's VIGUIERA DENTATA, a genus that on the phylogenetic Tree of Life stands near the sunflower genus Helianthus.

It also grows in Cuba and Central America. In this part of the world it's pretty common in weedy areas.

*****

MOUSE'S PINEAPPLE
Twining unobtrusively with other vines cascading over a stone wall in Pisté was the delicate species shown at http://www.backyardnature.net/n/11/110102mo.jpg.

You can see why one of the many English names used for the vine is Mouse's Pineapple. The pineapple is formed by the close clustering of numerous maturing inferior flower ovaries. Inferior ovaries are those from which the calyx's sepals, the corolla and the stamens arise above the ovary, not at the ovary's base, in which case it would be a superior ovary. The two conditions are diagrammed at http://www.backyardnature.net/inf_sup.gif.

In the picture at the left all but two corollas have fallen off the cluster of ovaries, while at the right a cluster's first two corollas have opened, the other ovaries still bearing unopened corollas. A close-up showing better how the corollas arise atop the ovaries is at http://www.backyardnature.net/n/11/110102mp.jpg.

The last picture also shows a low, sharp-pointed, triangular stipule connecting the base of a leaf petiole and the flower cluster. When you see the combination of inferior ovary with conspicuous stipules, automatically you should think "the Coffee or Gardenia Family, the Rubiaceae." In the New World tropics the Coffee Family is a big one, but also one of the easiest to identify families because those two field marks are so determinative.

Mouse's Pineapple, also called Redgal, Yellowroot and other names, is MORINDA ROYOC. It's distributed from southern Florida, Mexico and the Caribbean south through Central America to northern South America, especially on limestone. Though it's a native wild plant, I see it mostly in towns on stone walls, where it can grow 20 feet long (6m).

You might recognize that genus name, Morinda, as the same genus in which Nonis are found. Nonis are small trees much planted in the Yucatan because of the medicinal value of their fruits. Noni is described at http://www.backyardnature.net/yucatan/noni.htm.

Noni's flowers and fruits are very similar to Mouse's Pineapple's, but much larger. Mouse's Pineapple's fruits also are variously used medicinally, as well as an aphrodisiac, and as a source of yellow, orange, or red dyes. Martinez's Las Plantas Medicinales de México says that the plant is useful as a digestive tonic and against the jaundice.

At one time it was thought that plants from the Yucatán were a distinct species and were given the binomial Morinda yucatanensis. However, now Yucatán's plants are considered the same as Morinda royoc, and Morinda royoc is an old Linnaeus name, worthy of being preserved.

*****

MEXICAN LIME
Up North I never had a problem distinguishing between a lime and a lemon. A lime was a sweetish fruit tasting like lime Lifesavers and smelling like lime- scented aftershave. Lemons were yellow, very acidy fruits oval in shape with a low, broad nipple at one end. Down here I never see the thing that gringos call lemons, but they call fruits not seen up North "limones," or lemons, and "limas," or limes, are things more acid-puckery than any gringo lemon.

Wilfredo the milpa man refers to as a Lemón a tree beside the garden that my books call a Lime, even though that small tree's fruits are profoundly sour. You can see its small, two-inch-across (5 cm) flowers at http://www.backyardnature.net/n/11/110102li.jpg.

The garden tree keys out to Mexican or Key Lime, CITRUS AURANTIFOLIA. Among its field marks are the relatively small size of the flowers and fruits and the fruits' exceeding sourness. A fruit is shown at http://www.backyardnature.net/n/11/110102lk.jpg.

A view of the ovary with its thick style topped by a spherical, yellow stigma, the ovary cupped within a low "annular disk," with stamens arising between the disk's base and the petals, is shown at http://www.backyardnature.net/n/11/110102lj.jpg.

That "annular disk" is a field mark for flowers of the Citrus Family, the Rutaceae, and so are abundant "pellucid dots," such as those in the Mexican Lime's leaf when held against the sun, as shown at http://www.backyardnature.net/n/11/110102ll.jpg.

Those pellucid dots are filled with the fragrant oils that smell so good when Citrus herbage is crushed. The oils repel many kinds of herbage-eating insects.

Though the Maya regard this species as their own, calling it Limón Criollo, or "Native Lemon," Citrus aurantifolia is native to Asia's Indo-Malayan region. It's thought to have been introduced into Europe by Crusaders from Palestine, where it was brought by Arabs who got it in Asia. The Spanish introduced it into the New World, there being a report of it commonly growing in Haiti in 1520. It must have been brought to Mexico early during the Conquest.

So, the Maya have known the tree for nearly 500 years, during which time they well may have developed a distinctive Maya cultivar. The small, very acidy fruits, tasting and smelling not at all like a lime-flavored Lifesaver, but seeming to me just like the taste of a gringo lemon, make wonderful lemonade, and the laundry staff uses the fruit's juice to remove spots from the wash.

Purdue University provides a Mexican Lime page with more about the species' history, propagation and culture, varieties, and more, than you want to know at http://www.hort.purdue.edu/newcrop/morton/mexican_lime.html.

None of that helps me figure out, however, what Citrus species produces the sweet, fresh-smelling fruit I've always thought of as a lime. At least I'm not alone in my lemon/lime confusion. The Wikipedia Lime Page lists about 16 taxa commonly known as "lime." See the bottom of http://en.wikipedia.org/wiki/Lime_(fruit).

*****

CITRUS LEAF PETIOLES
Maybe you noticed in pictures of the Mexican Lime's leaves linked to above that the leaves' petioles bore "wings." Wings occur on many Citrus species. You can see especially wide petiole wings on a Grapefruit tree's leaves, and narrower ones on our Mexican Lime, at http://www.backyardnature.net/n/11/110102wi.jpg.

In those pictures the broad leaf blade extends out of the picture below. The two topmost points are where the petioles attached to the stem. The flat, green, leafy expansions on the petioles in the center of the picture are wings.

I don't know what purpose wings serve, other than to provide extra chlorophyll-bearing surface area where photosynthesis can occur. Many Citrus species have wings and often the wings' widths can help us identify which Citrus species we have. You can see in the photo that Grapefruit tree wings are much wider than wings on Mexican Lime petioles. Citron and Lemon petioles are wingless. Sweet and Sour Oranges both have narrow wings.

I thought about constructing an identification key based only on petiole wings but when I got into it I found too much overlapping of widths for such a key to be useful. Still, keeping in mind petiole wing width sometimes can be helpful when you're trying to figure out what kind of Citrus stands before you.

*****

DOUBLE PURPLE DATURA
Wandering Pisté's backstreets, next to a humble, thatch-roofed hut and bending over a half-collapsed stone wall there was a bushy, five-ft-tall (1.5m) herbaceous plant with the spectacular blossom shown at http://www.backyardnature.net/n/11/110102da.jpg.

That blossom is about seven inches long (18 cm). It's a double-blossomed cultivar. A close-up showing better how the inner and outer corollas relate is at http://www.backyardnature.net/n/11/110102dc.jpg.

Some fruit-capsules on the plant were mature and apparently had been broken open by birds feeding on the large, brown seeds. You can see such a fruit at http://www.backyardnature.net/n/11/110102db.jpg.

This horticultural creation is derived from the wild Datura metel, which is native to India and southeast Asia. The cultivar is known as 'Fastuosa," so the technical name for the plant is DATURA METEL 'FASTUOSA.' The horticultural form is so widely planted throughout the world's tropics that it's known by numerous English names, such as "Purple Hindu," "Blackcurrant Swirl" and "Cornucopaea." Since it's a member of the genus Datura and bears double, purple-tinged flowers, maybe the most appropriate name is "Double Purple Datura."

At first I thought that this was a form of Angel's Trumpet, Brugmansia arborea, native to the Andes, which we met back in Querétaro, and which still is shown at http://www.backyardnature.net/q/datura-a.htm.

Among the big differences between Angel's Trumpets and Double Purple Datura is that the Angel's Trumpets' flowers are pendulous on a woody, perennial bush, while the Double Purple Datura's flowers are erect on herbaceous, annual stems.

You may remember the Carlos Castinada books of several decades ago in which the Yaqui Indian called Don Juan concocted hallucinogenic potions using "Devil Weed," which was a Datura -- the same genus as our Double Purple Datura. Don Juan was using a different species, but in fact all parts of our Pisté plant, as well as all other species of Datura, are poisonous. Eating this plant in large enough quantity can be fatal for humans, livestock and pets. Even eating small amounts of it can cause severe headache, hallucinations or unconsciousness.

That being said, the Asian plant from which this cultivar was developed has been cultivated for centuries in China and India for medicinal uses, extracts of its leaves and seeds being used for a very wide range of ailments. However, the medicinal dose is very close to the toxic dose, so amateur healers shouldn't fool with this plant, or any of the Daturas.

*****

FINE-TUNING BUDDHA
Here lately the weather has been wonderful -- chilly mornings with warm, sunny, breezy afternoons overabounding with sunlight. As the dry season progresses the vegetation yellows, and there's an occasional swirl of leaves falling from trees. It's reminiscent of September up North.

I'm glad my life is uncomplicated enough for me to enjoy these days. Most folks I meet are hurrying, hurrying, hurrying, trying to see everything, do everything, or to make money.

My life is uncomplicated because for a long time I've made choices meant to keep my life simple. Largely this has meant deciding to do without things that other people feel they need. The moment one yields to the hungers for wealth, status or power, complications arise, I find, and pleasures of the simple life vanish.

Buddha taught the same long ago: To find peace and contentment, subdue your hungers.

Still, in recent years, I've been questioning the extent to which one's hungers should be subdued.

During my unsettled early years "finding peace" by quieting my hungers sounded like a good goal. Later, however, when I began thinking in terms of us living beings as "nerve endings of the Creator," I started doubting that "peace" and all the hunger subduing that implied was an appropriate ultimate goal. After all, the purest form of peace, as the Buddha would have agreed, is nonexistence. Yet the Universal Creative Impulse unambiguously brought us into existence, wired and programmed to feel many sensations, not just peacefulness. Surely the Creator is saying something by putting us here the way we are.

Still, I think that the Buddha got it right about the desirability of subduing one's hungers -- at least insofar as that simplification bestows time to enjoy beautiful things and to meditate on what's being experienced, good and bad.

But it seems to me that subduing hungers and simplifying life can go too far. Indulging no hungers at all implies an inactive, detached, apathetic existence completely inharmonious with the rest of the roiling, lustily evolving Universe.

As always, The Middle Path beckons. One just needs the wisdom, strength and luck to be able to recognize it, and embark on the Path when it stands before us.

*****

Best wishes to all Newsletter readers,

Jim