Two years ago, Lotter pushed through these same thorny woods near Starvation Creek and embedded microchips in 1,400 cycads to identify each plant. Now most of the palm-like cycads he had marked were gone - dug up by thieves and sold to collectors.

``All that is left are seedlings and a few old, dying plants," fumed Lotter, a researcher for the Mpumalanga Province Parks Board. A few larger plants, hundreds of years old, were left broken and dead along the trail.

Last week, Lotter's mission was to locate the sites where two encoded cycads had grown before they turned up 150 miles away, in the backyard of a Johannesburg landscape artist. After locating the sites with a hand-held satellite positioning device, Lotter photographed the craters as evidence in the landscape artist's trial for theft of endangered plants.

Despite such high-tech efforts to protect the endangered species, conservation officials appear to be fighting a losing battle against cycad collectors, whose passion for the primitive species threatens to destroy the very plants they love.

``Many collectors ardently believe what they're doing is to conserve the plants, and they're not keen to hear what they're doing is killing them," said John Donaldson, assistant director of conservation biology for the South African National Botanical Institute.

Sometimes confused with palms and ferns, cycads are thick-trunked plants with rigid spiked leaves. They were the predominant plant species during the Jurassic period. Dinosaurs fed on cycads, and much of the coal and oil being extracted from the earth were once a cycad forest.

Cycads were mentioned prominently last week in a report by the World Conservation Union, which concluded that 12.5 percent of the world's seed-producing plants and ferns - nearly 34,000 species in all - were threatened with extinction.

The Nature Conservancy cites two primary threats to plants: loss of habitat and competition from the introduction of nonnative species.

With cycads, there is an additional factor: human greed. Some cycads are worth a lot of money. The two stolen Encephalartos laevifolius cycads found in the Johannesburg landscaper's property were valued at about $3,000 each.

Cycads grow very slowly; some species take 100 years to grow three feet in height. Nurseries only sell small plants, so a collector who wants a big plant can either buy a cycad from another homeowner or get one from the wild - generally from a smuggler.

``People in Johannesburg don't want to buy small plants," said Herman Erasmus, head of investigations for the Mpumalanga Parks Board. ``They want to be big shots and have big plants. There's a lot of snob appeal in these things."

Traditionally, Africans have had little use for cycads. In some cultures, people ate the starchy trunks, but they made an unappealing meal. Cycads were mostly used as a supplementary food source during famines.

Cycad seeds are poisonous, as numerous explorers discovered the hard way. Capt. James Cook's discovery expedition to Australia in 1770 came to a halt after cycad seeds made his crew violently ill.

Parks officials said that in recent years traditional herbalists had begun pillaging cycads - but only after cycad collectors began paying serious money for the plants. The traditional healers, called sangomas, say the cycad medicine creates wealth for those who use it.

Conservation officials say the biggest cause of the plundering of cycad forests is collectors who are obsessed with owning every species.

There are 185 species of cycads in tropical and subtropical parts of Africa, Asia, Australia, South America, Mexico and the Caribbean. International trade in four of the 11 cycad genera is banned under the Convention on International Trade in Endangered Species of Wild Fauna and Flora.

All 40 cycad species found in South Africa are endangered, some so rare that they are extinct in the wild. Only a handful of one species, Encephalartos woodii, still exist. They are all males. Botanists can produce new plants from suckers generated from older plants, but the offspring are also male. Unable to reproduce in the wild, the species is condemned to life as a museum piece.

In South Africa, some cycad colonies have been virtually wiped out by collectors seeking a sample. When a botanist 12 years ago discovered a new species, Encephalartos cerinus, thieves plundered so many of the plants they nearly wiped out the species within weeks of its discovery.

Recently, a professor discovered a new cycad species in South Africa, though its location is still a secret. ``We've learned our lesson and we don't disclose the location," said Hanneke Grobbelaar, chairman of the Transvaal Branch of the South African Cycad Society and the owner of a cycad nursery.

Some homeowners have sold their cycad collections for up to $100,000. ``It's an excellent investment," Grobbelaar said. ``Since cycads live for hundreds of years, it's better to put your money in cycads than in banks."

South Africa has some of the world's strictest laws controlling cycad trafficking. Since 1965, South Africans have needed a license to possess a cycad. But some people claim they owned their cycads before the law went into effect or were given old cycads by neighbors or relatives. Penalties for possession of an unlicensed cycad were no greater than a speeding ticket.

Conservation officials have tried other means to curb thefts. Some marked rare cycads with nails. Others tried painting or photographing cycads so the stolen plants could be distinguished later. None of the measures was very successful, said Donaldson, the official with the National Botanical Institute.

The latest effort has been to sink the inch-long, nail-like microchips into the plant. The microchip gives the cycad a unique number that can be read by a hand-held scanner. But smugglers are devising methods of finding the microchips and digging them out.

``It's only a matter of time before they figure a way around the microchips," said Tommie Steyn, the Mpumalanga park official who created the investigations unit. He said the parks board is considering taking genetic samples of its rarest cycads, though other officials say that taking DNA fingerprints is unrealistically expensive.

``We are trying to change the status of cycads," Steyn said. ``We want them to have the same kind of stigma as a fur coat. If somebody's got a big cycad in his garden, the neighbors must look over the fence and say, `Where'd you get that thing?' "

Erasmus, the head of investigations for the parks, said cycad smugglers pay $1,000 for a pickup truck full of plants, and there is no shortage of poor South Africans willing to dig them up. A cycad dealer can recover the cost by selling just one plant to a suburban gardener who wants to impress his neighbors.

Erasmus, a beefy former game park manager, made his biggest cycad bust in 1995, when he arrested a cycad smuggler filling two tractor-trailers with Encephalartos altensteinii. The 40 tons of cycads were worth more than $1 million.

The thief, Konstantinos Giuleas, had obtained permission from local officials of the African National Congress to take out the cycads. The officials professed that they did not know the plants were endangered. Giuleas was fined $7,500 and forfeited his truck, but the government officials weren't prosecuted.

It was not the only time a government figure was involved in a cycad theft. Last year, Guateng Province investigators charged a police official with possession of cycads that came from public lands in KwaZulu-Natal Province.

Three months ago, Erasmus collared Ernie Bouwer, 52, a landscape artist who lives in Sandton, a wealthy suburb of Johannesburg. Bouwer was caught with two cycads that contained microchips. Investigators said eight other Laevifolius cycads, also probably stolen from Starvation Creek, appeared to have had their microchips removed.

Bouwer has been convicted twice of possession of unlicensed cycads, but he received small fines, about $200. He has 1,500 cycads on his property.

This time, because investigators can prove that two of the cycads were stolen from public lands, they are trying to build a more serious case against Bouwer and confiscate his entire collection. He also faces 10 years in jail.

Bouwer said he is a legitimate dealer in cycads. ``I buy thousands of plants each year from other collectors," he said. ``I keep the best ones for myself and sell the rest."

He said that he did not knowingly buy stolen plants, and that his previous convictions were entrapments. ``I have more than a thousand plants on my property, and they only found two that had microchips."

Bouwer said he did not feel he was contributing to the depletion of the species in the environment, but was helping to propagate cycads by selling them to private owners.

What is the appeal of owning so many cycads?