Plant Seeds Are a Letter of Life to the Future By RON SULLIVAN Special to the Planet

Friday December 30, 2005

Our vegetable love would grow 

Vaster than empires and more slow. 


Andrew Marvell was making a counter-example when he wrote those lines to his coy mistress. His point was that, being mere humans, members of the animal realm, we have only a short time to do what we want to, given even the classical three-score-and-ten years to live. We’re on the long-lived end for mammals ourselves; most of the best-known prodigies of animal longevity are herps like tortoises or fish like certain carp—and there’s evidence that some small, unprepossessing North American freshwater shellfish might persist in their quiet ways for a century or two.  

In fact, we have mammals around us who are effectively annuals—some shrews, especially the males, who run around in a frenzy of competing and courting and mating as soon as they reach maturity, and then drop dead. There are fish who don’t do much better, and of course lots of invertebrates with several generations in a year. In that, they share the strategy of some plants, who grow, flower, set seed, and wither all in the course of a year or a season. Such plants tend to be small and showy—they invest more in flash than substance. 

No animal approaches, in a single life, the record of the plants who use the other strategy: long, slow growth. (I’m assuming we’re not quite at the point of counting fungi as animals, though they seem closer and closer relatives, the longer we look at the structure of the cladistic tree of life.) The redwoods up- and downcoast live for centuries; there are bristlecone pines in the White Mountains older than any religion I know of, never mind mere nations; there’s a humble ringclone of creosote bush down in the desert northeast of Los Angeles that experts are saying is between 9,400 and 11,000 years old.  

A creosote ringclone forms when the plant, in its usual habit, bends its growing stem to the ground and takes root again where it touches. Eventually the oldest section dies off, and the new part of the plant keeps going in the same way. As multiple stems work thus, each leaning a little away from the rest, you get a circle of the new plant tissue around a center of its own dead wood. It’s still all the same plant. 

Ancient-growing trees like redwood use reproductive strategies closer to those of turtles than to the styles we sort-of-slow mammals use. Rather than investing lots of energy in a few offspring who will, we hope, also live long and prosper, they scatter millions of seeds in thousands of cones regularly over the course of their long lives. Of course, most of those seeds don’t grow up to match their parents, becoming instead part of the economy of the forest or desert that supports and is supported by the matriarch plants.  

But there’s one advantage we mammals can’t hope to have without some technology further advanced that we’ve ever managed. Plant seeds can “live”—or maintain their potential to grow—for very long times. National Geographic News published an item last November by John Roach, an account of the successful germination of one of several date palm seeds found in the ruins of Masada. The seeds have been carbon-dated to be about 2,000 years old. 

Roach talked to a researcher in November: “‘It’s 80 centimeters [three feet] high with nine leaves, and it looks great,’ said Sarah Sallon, director of the Hadassah Medical Organization’s Louis L. Borick Natural Medicine Research Center in Jerusalem.” She’d asked a desert agriculture specialist, Elaine Solowey, to try germinating a few of the unearthed seeds. Planted on the holiday Tu B’shevat, the trees’ New Year, one of them had sprouted and produced felty gray, then healthy-looking green leaves. It remains to be seen whether the tree is a male or a fruit-bearing female. It is apparently a member of a species or cultivar wiped out completely by 500CE.  

This is a domestic plant, and extreme, but wild trees can keep their seeds dormant for decades. Sometimes they wait for a fire to open their cones and slap the seeds awake; sometimes they sleep in some critter’s forgotten food cache until water stirs them. But to a being who might live a thousand years, such a time capsule, a letter to the future, probably looks more ordinary than it can to the fast and flashy likes of us. 



Ron Sullivan is a former professional gardener and arborist. Her column on East Bay trees appears twice-monthly in the Daily Planet. Her “Garden Variety” column appears weekly in the Planet’s East Bay Home & Real Estate section.?