Oaxaca Journal (6 page)

It will take two or three hours to reach the meadow—about eighty or ninety kilometers distant—with stops along the way. This part of our route, along the Pan American Highway, used to be, Luis says, an Aztec highway. But we turn off the Pan American Highway after a couple of kilometers, onto Highway 175, which goes from the Pacific Ocean to the Gulf of Mexico. At the junction is a statue of Benito Juárez, with panels around it showing episodes from his life. Luis promises to tell us all about him later—his tone is one of affection and reverence. He says that Juárez was born in the village of Guelatao, which we will be passing through.

We are now driving to the East Sierra Madre. I ask Scott about the many red flowers we pass. They are
Solanum
, he says. He tells me that some other species of
Solanum
are bat-dispersed and have greenish or white flowers, while these, bird-dispersed, have red flowers. The bat-dispersed ones waste no metabolic energy producing what would be, for them, a useless red pigment.

Scott and I speak of the coevolution of flowering plants and insects in the last hundred million years, the development of the dramatic colors and shapes and scents by which flowering plants lure insects and birds to their flowers. And we speak of how certain kinds of red and orange fruit seem to have appeared only in the last thirty million years or so, in tandem with the
evolution of trichromatic vision in monkeys and apes (though birds had developed trichromatic vision long before). Such fruits, a staple of many monkey diets, were particularly visible to trichromatic eyes in the tangled jungle foliage, and the plants, in turn, relied on the monkeys to disperse their seeds in their feces.

The marvel of such coevolution, such mutual adaptation, is central to Scott’s interests. He and his wife, Carol Gracie, together and separately, have spent their lives exploring it. But I, though I also appreciate the beauty of such adaptations, prefer the green and scentless world of ferns, an ancient green world, the world as it was before the coming of flowers. A world, too, with a charming modesty, where reproductive organs—stamens and pistils—are not thrust out flamboyantly but concealed, with a certain delicacy, on the undersides of leafy fronds.

Long after the sexuality of flowering plants was recognized, the reproduction of ferns remained a mystery. It was believed, Robbin told me, that ferns had seeds—how else could they reproduce?—but since no one could see these, they assumed an odd and almost magical status. Invisible themselves, they were thought to confer invisibility on others: “We have receipt of fern-seed, we walk invisible,” says one of Falstaff’s henchmen in
Henry IV
. The great Linnaeus himself, in the eighteenth century, did not know how ferns reproduced, and coined the term cryptogams to denote the hiddenness, the mystery, of their reproduction. It was only in the middle of the nineteenth century that it was discovered that in addition to the familiar fern plant with its spore-bearing fronds, the sporophyte, there
also existed a tiny, heart-shaped plant, very easily overlooked, and that it was this, the gametophyte, which bore the actual sex organs. Thus there is an alternation of generations in ferns: Fern spores from the fronds, if they find a suitably moist and shaded habitat, develop into tiny gametophytes, and it is from these, when they are fertilized, that the new sporophyte, the baby sporeling, grows.

Most gametophytes, like liverworts, look much the same. The beauty of ferns, their enormous range of form, from towering tree ferns to tiny filmy ferns, from the delicately divided, lacy fronds to the thick, undivided leaves of staghorn and bird’s-nest ferns—all this resides in the sporophyte form. And the sori themselves take on a variety of forms: whelks and bubicles in some species, creamy masses in others, and beautiful, fine parallel lines in bird’s-nest ferns and others. Part of the joy of ferning is in turning over the fertile fronds and spotting these sporangia.

John Mickel loves the fertility, the sporangia of ferns. “Ooh!” he says of an
Elaphoglossum
, “isn’t that nice, smeared sporangia on the other side.” Of
Polystichum speciosissimum:
“Look at those scales and incurved margins!” And of a
Dryopteris
, which he has just found in the forest: “Fertile as a moose!” he says, gazing at its sporangia. John, Robbin whispers to me, jokingly, has “pteridological orgasms.” I have often seen these at our Saturday fern meetings. His voice will rise, he will wave his arms about, use the most extravagant language (comparing spores, sometimes, to caviar): “It makes one’s heart go pit-a-pat.”

My own impulse, like John’s, has always been to cryptogamic botany; I find flowers, with their explicitness, their floweriness, a little too much.

Indeed, many of us share this feeling, and when we have our AFS meetings on Saturdays, any mention of flowering plants tends to be accompanied by a sort of joking apology: “If you will excuse my mentioning it …” or “I know you won’t like this, but …” You might think, hearing us on a Saturday morning, that we still lived in a flowerless, Paleozoic world, where insects play no role, and spores are dispersed by wind and water only. (I should add, in all fairness, that there is equally little reference among us to plants lower than ferns—mosses, liverworts, seaweeds, etc.—and I, with my predilection for the primitive fern allies and mosses, am sometimes, I imagine, suspected of apostasy.) Of course, the particular passion for ferns is embedded, in all of us, in a much broader botanical and ecological context—even the most ardent of fern systematists are aware of this—it is
just that we pretend at times, in a sort of nostalgia or in-joke, to have no interest in the wider plant world.

Among my fern-loving fellow travelers, however, there are quite a few experts on flowering plants, too—J.D. and Scott among them—and now, on the bus, as we pass by some trees laden with glorious white flowers, Scott draws our attention to them. These, he says, are tree
Ipomoea. Ipomoea
, I query? The same genus as the morning glory? Yes, says Scott, the sweet potato, too. I think back to my California days, in the early 1960s, when morning glory seeds—one variety of them, at least (the “Heavenly Blue”)—were used for their psychedelic power—since they contained ergot compounds, lysergic acid derivatives, similar to LSD. I used to get three or four packets of the hard, angular black seeds, pound them to powder with a mortar and pestle, then—this was my special innovation—mix the ground seeds with vanilla ice cream. There would be intense nausea for a while, followed by visions of a very personal heaven or hell. I often wished for the right place and time to take it—and this would have been in south Mexico, where the morning glory grows easily and abundantly in the mountains, and its seeds,
ololiuhqui
, can be kept indefinitely without losing their potency. Indeed, I am told, the plant itself (which the Aztec called
coatl-xoxo-uhqui
, green-snake, for its twining vinelike habit) was regarded as a sacramental plant, and used in the presence of a medicine man, a
curandero
.

In
Plants of the Gods
, the great ethnobotanist Richard Evans Schultes and the chemist Albert Hoffmann (who was the first to synthesize LSD and to report its effects), describe how every culture has discovered plants with hallucinogenic or intoxicant
powers, powers often seen as supernatural or divine. But the Old World knew nothing like the powerful hallucinogenic drugs of Mexico—
ololiuhqui
(which the Spanish, when they encountered it, called
semilla de la Virgen
, seed of the Virgin); the sacred psilocybin mushroom,
teonanacatl
, God’s flesh (its active constituents also lysergic acid derivatives); and in the north of Mexico, overlapping the southern U.S., the buds of
Lophophora williamsii
, the
peyotl
cactus, sometimes called mescal buttons (though these have nothing to do with mescal, the distilled liquor made from the agave plant).

As the bus churns up the mountain, Scott and I chat about these plants, and the more exotic South American hallucinogens, such as
ayahuasca
(the vine of the soul), made from the Amazonian vine
Banisteriopsis caapí
, which William Burroughs and Allen Ginsberg describe in
The Yage Letters;
and the trypt-amine-rich snuffs
—Virola
, yopo, cojoba—the way in which their active ingredients are all so similar chemically, and so close in structure to serotonin, a neurotransmitter; and the way in which they were all discovered in prehistoric times (was it by accident, or trial and error?). We wonder why plants so different botanically should converge, so to speak, on such similar compounds, and what role such compounds play in the plant’s life—are they mere by-products of metabolism (like the indigo found in so many plants); are they used (like strychnine or other bitter alkaloids) to deter or poison predators; or do they play some essential roles in the plants themselves?

It is extraordinary to sit next to Scott on the bus. He identifies, or can identify, everything we see, and he knows every plant in its meaning and context; the whole world of evolution, competition,
adaptation, moves through his mind as we pass. I am reminded of another bus ride, in the state of Washington, with a friend from Guam, and how her knowledge of geology brought the entire inorganic landscape, all the landforms around us, as we passed them, to life. She, too, as it happens, was primarily a pteridologist, but her geological eye, so well-developed, gave an extra dimension, meaning, to everything we saw.

Accompanying us on the bus is Boone. I am not quite clear, at this point, as to who and what Boone is, though I know that he is an old and highly respected friend of John Mickel’s—they met here in Oaxaca back in 1960—and that Boone has worked here as a botanist or agriculturist ever since. He has a house for visiting botanists, apparently, high up in the mountains, near Ixtlán, and we will be visiting this in a few days. Boone must be in his seventies; he is short but broad and strongly built, agile, and has a fine head with a cowlick of hair over his forehead.

He is evidently an expert on the trees of Oaxaca, and now, as we move higher into the mountains, and oaks and pines become the dominant vegetation, he gets up in the bus and starts to speak to us. “Most of the oaks,” he starts, “are in such an active state of evolution that they cannot be identified. Some floras speak of thirty species, some of two hundred—and these hybridize constantly.” The first pines we see have short needles and cones. Then, a few hundred feet higher up, pines with longer needles and larger cones, another species.