Moth Orchids

I believe most people simply call them Phalaenopsis, which is the scientific name of the Moth Orchids, a genus from tropical Asia in which all of the species have lateral petals resembling the wings of a moth. Indeed, the Latinized word Phalaenopsis means "looks like a moth."

When I was a kid, these were pretty exotic plants. But today they approach being common. People have discovered that a nice Phalaenopsis is a practical and elegant way to keep fresh flowers. The plant and flowering stalk are as fine a combination as any floral arrangement, flowers and buds are perfection, and the longevity beats any flower arrangement hands-down. A nice Phalaenopsis, purchased for $15-40 at markets and nurseries around the country, can remain in bloom for weeks..., weeks! Beyond being a more sustainable way to enjoy fresh flowers, the plant becomes a new form of chia pet - a fun project for people to pursue - an attempt to keep the plant alive and even reap a new harvest of flowers.

And the return of flowering is a real possibility. Just keeping a plant in a reasonably good living state is occasionally rewarded by growth of a new flowering branch out from a stem from which every flower has long-since fallen. So afficionados have learned to leave green, healthy flowering stems on the plant until it is clear not much more will happen. Success comes when the plant continues to send out new flowering stems from the base of the stem.

The trick, however, is that people who aren't familiar with orchids are seldom clued into an aphorism of the orchidist - happy roots, happy plant. Those nifty plants, sold at what seem to be impossibly low prices, usually have a built-in problem. They are potted in a way that promotes good "finishing-off" growth and makes the plant practically bullet-proof during the first few weeks of flowering. But the underlying problem is that the medium (the stuff packed around the roots) is seldom a good medium to promote new growth.

To stand a chance at keeping the Phalaenopsis living healthily enough to rebloom, there is work to be done. As soon as it gets to the end of good flowering, someone needs to remove it from the pot. What you will discover is remarkable. Most Phalies sold in the cut-flower trade are potted tightly in sphagnum moss - the kind called New Zealand sphagnum. The sphagnum used is fresh; the leafy scales have an astounding capacity to hold water, and the sphagnum doesn't quickly break down into humus. In fact, many orchid growers use this sphagnum - but they use it in open baskets and pots that give ample drainage and allow air to circulate around roots. But no orchidist packs the sphagnum and roots so tightly into pots as you will see for these flowering plants. They are treated, in reality, like whole-plant cut flowers, not intended at all for long-term survival.

The sphagnum, though perfectly suited for wrapping the roots, is pretty expensive, and can actually hold too much water in the center of the pot. Imagine a light-weight, cheap, non-absorbent, and non-degrading substitute a producer could use to stuff in the core of potting material, and you may guess in advance that growers frequently pack styrofoam packing peanuts into the space at the center of the rootball.

It drives me crazy. Here you are, breaking apart the rootball of a spent Phalie, expecting to compost the refuse, and out fall several white styrofoam packing peanuts. Though practical, there is just something offensive about the whole situation - growers wrapping orchid roots in a blanket of sphagnum and cramming them into a tight plastic pot-like bag with a heart of styrofoam. Weird.

So how do you pot these used plants? How do you bring them back? This is what I have been working on for the past week, testing some ideas, talking to collectors and growers, cleaning and repotting. Here is what I learn from others. Phalies need annual repotting; even if they were in good growing medium from the start, a successful grower would likely have repotted the plant after flowering anyway.

We are moving back to terracotta pots, a special kind perforated with holes to allow for drainage and air movement. We are using medium bark, and selecting pots that seem slightly undersized. If we have to use larger pots (7-8 inches), we are installing a small inverted pot or a red brick under the plant, to eliminate the core of medium that seems to break down into organic mush the quickest. Orchids that are natively epiphytes (growing on the trunks of trees, with their roots totally exposed) do not like rotting bark. Roots found in rotten bark are seldom healthy.

You know when an orchid root is healthy because it has an active growth tip, and is intact and fleshy, covered with the white, barkish velamen. And as we said earlier, happy roots, happy plants. When the roots of a Phalaenopsis are not healthy, the damage soon shows in withering foliage, browning basal leaves, and general reduced size.

There is a lot more that can be said of these wonderful plants. White-flowered forms are wonderful, but the colors and color patterns that continue to appear in the trade are spectacular. The numbers of plants imported (to be brought into flower) increases each year. But the market seems far from saturation, and to the dedicated student of orchids, this trend opens wholly new territory that might bring in new converts.

Soaring Seed

Just beside our garage is an arbor covered with Wisteria, specifically the cultivar 'Cooke's Purple' - a vigorous vine that can make a canopy dense with pendent inflorescences of blue-purple pea flowers. The vine is coming into bloom right now, and we are promised a glorious sight. By the time flowering is completed, the light green leaves will just have begun to expand, and in short order the vine will create a good shade.

When in full flower, Wisteria resonates with the buzzing sounds of bees, hovering and clambering from flower to flower. This activity results in some pollinations that yield fruit, which grow to become velvety green, lumpy and woody beans. By autumn, when the leaves have fallen, the beans are brown and dry - and hard.

A few autumns back I was clearing the garden area around the Wisteria arbor, which is also a potting bench. To wash the dust off all of the surfaces, I hosed down the structure, vine and all. Within a few minutes of the drenching, while cleaning around the garage entrance, I heard a crack/pop, and the tap of a landing, then another, then several - like a handful of popcorn reaching its modest crescendo in a pan. But the lid was off and seed were flying in all directions..., beautiful, flattened, shiny, and speckled brown. They pelted tools and shelving in the garage, flew into potted plants, and landed in soil and lawn - as far as 15-20 feet from the the scores of fruit that were curling and snapping open once soaked with water. It was a stunning performance, and something I had not expected at all.

So no surprise when, while cleaning around the arbor this winter, I discovered seed all around - in pots and soil. And a lot of them had successfully sprouted; little Wisteria plants showing up all around. I steadily weed them out, knowing there will be more, for it is March again, and the mother plant is back in bloom. I will soon smell their pea blossoms, wondering if my lingering perception that they smell like grape jelly will be confirmed by reality, or will prove to be an altered memory, inspired by the faint resemblance of the flower cluster to clusters of grapes. And if I have a moment, before the rains that come around Thanksgiving, I will hose down the arbor, just for the fun of it.

A Change in the Sources and Forces of Change

My basic understanding of plant evolution has come from courses and books that spoke to the sources of variability in a population, and the forces that impact the survival of certain individuals over others, survival that played out in the production of offspring that would come to define the next generation. Sources relate how new genetic possibilities arise. Mutation is best-known by the public. This happens when wholly new “genes” (really, they are different options, alleles) appear in the genetic material of a population; if a mutation impacts a place where sex cells are made (a pollen sac or an ovule)then new genetic possibilities may become available for future generations. But there are other ways a population can get fresh genetic options, such as through successful sexual encounters with other populations that result in hybrid progeny. We also know that genetic material can be transferred from one plant to another through bacterial and viral activity. Over time, a lot of new options have given rise to new forms in plants.

I can’t recount all the different forces that are normally discussed, pressures on plants from variability in soils and changes in climate, the activity of pollinators and herbivores (which many people, today, call predators.) Pressures mean that certain plants will have greater success in producing viable offspring than others.

Every plant you encounter today has its own complex natural history, and its own, reticulated story of change through eons and countless generations. Most significantly, every living plant today is the current link in an ongoing chain of life that has never been interrupted, not for the billions of years since the first living ancestor(s) of that very plant came into cellular existence. Plant life is not spontaneous; it is serial – life begets life – cells are formed only from nuclei and cytoplasm that “know” how to make cells. Somehow the wondrous differing forms and biologies we call species, each begetting their own kind, reach back through the struggle for survival to common ancestors.

Looking back on what I understood about evolution, I seem to have missed books and teachers giving much attention to the force of disease. We talked about threats to individuals and populations, and I’m certain we mentioned disease, but it seemed casual. And I know that in the last few decades scientists have discussed more about evolution of disease resistance through production of secondary compounds, such as flavonoids. But to my mind, the role of disease in plant evolution is understated.

Plant disease is a big deal. In the last century, disease has proven to be the most immediate source of devastation to plant populations around the world. When E. Lucy Braun studied the Eastern mixed mesophytic forest, she defined the zone based on eight dominant trees. Major populations of two of those dominants, American Chestnut and American Elm, were wiped out in short order through 20th century introduction of diseases from Europe, diseases that had previously been endemic to European relatives. Today, American Beech is threatened by introduction of yet another disease.

Books have appeared in the last two years that portend extinction of cultivated bananas, due to fungal disease that is readily spread. The world’s citrus crop appears in eminent danger of collapse due to spread of what is called greening disease. A native disease of Hevea brasiliensis, the Rubber Tree, doomed commercial production of rubber in Manaus.

None of these diseases is newly evolved. Their potency is no more than ever, it was their dispersal that had held disaster at bay. Human activity, spreading disease and vectors, establishing monocultures that incubate inoculum, is the wind behind the sails of infection. Surely, each disease would made its way further afield without human activity, but not so quickly as today, not so quickly as to defy the steady counter-force of evolutionary selection for resistance.

Seeing how quickly a new disease can annihilate a population reminds us that disease has been a significant player over history. Certainly, disease has not been the force that drove flower shape, or dispersal success, but it has certainly penalized naively successful lineages that came in contact with resistant disease-bearing groups And diseases evolve also, in most cases even more quickly than do plants. So there has been no shortage of the impact of disease on evolution of plant populations.

Interestingly, the ancient formula seems upended. Because humans basically have taken over management of the planet, we have altered, in some cases, neutralized the normal forces of evolution; the historical evolutionary process is dysfunctional. However, the role of disease in plant survival, thus plant evolution, becomes greatly magnified through human activity. Disease has become the great tyrant of modern plant populations. And the Genie has escaped the bottle; there is no going back.

From an agricultural and horticultural perspective, evolution and spread of disease and pestilence appear to threaten all plant life on earth. At the very time humans have elevated the spread and impact of disease, we have also come to fear technology that will prove necessary to conserve plant diversity – especially the diversity of food crops. Genetic modification of plants will, in the end, prove crucial to the survival of some of our most important and wonderful plants. One wonders how society will negotiate the concerns and politics of genetic technology, but the disease-driven trend of plant diversity is creeping extinction.