There is no green army behind Rose Hoffman. No legion of environmentalists has rallied to her cause. Still, the 76-year-old woman persists, a lone crusader who simply worries about endangered trees she does not own but has admired for years as she drives by.

You might say Rose has been a thorn in the side of officialdom. "I have written to everybody," she said.

And they have responded. They all appreciate her concern.

But no one--not Gov. Parris N. Glendening (D), not County Executive Wayne K. Curry (D), not the highest or the lowest of bureaucrats--will give her what she wants: protection for a bunch of bald cypress trees that line both sides of Old Crain Highway on the way into Upper Marlboro.

These swamp cypress, not native to the area and choking on vines, were planted in 1925. They stand tall and mature, forming a shady canopy arching above a 2,000-foot stretch of scenic road leading north into the county seat. They are said to be the northernmost stand of the species, which is commonly found in the swamplands of the Southeast.

But development is coming to this corner of Prince George's. Though even the developer is opposed, county public works officials have decreed that the road must be widened where half the 100 trees stand in order to accommodate Meadowgate Estates, a community of $400,000 homes rising on two-acre lots.

The trees are in the way of what some call progress. Rose Hoffman doesn't care.

Hoffman, who lives a few miles away near Andrews Air Force Base, has been battling forces both natural and governmental for five years, and she is not about to give up.

"A splash here and there," she said of her efforts. "I surface, then I go underground . . . and I come out of the ground."

She does not fit the profile of your typical Washington area tree-hugger. A 1941 graduate of the old Marlboro High School, she worked as a government secretary for 32 years, mostly for the Census Bureau. As a food "demonstrator" at Safeway in Upper Marlboro for eight years, she came to appreciate the trees driving to and from her job.

She keeps on scraps of paper the names and numbers of those she has called or written, and a file bulges with letters she has received, many of them responses to other letters written by County Council members on her behalf.

"Current resources are such that these rural roadside trees cannot be afforded any special maintenance or care," wrote one county official, who did, however, agree to clear around the base of each tree. That was in 1994.

Hoffman writes steadily. But the answers she gets from public officials all sound the same.

"Your efforts to preserve these fine old trees are commendable," wrote Glendening, a former Prince George's county executive. "It is always encouraging to hear from citizens who are willing to pitch in and help solve a problem in their neighborhoods."

But the governor noted that the trees were not on a state road and therefore he couldn't help. It's up to the county.

"I appreciate your concerns about removing the older trees as part of the roadway improvement project," Curry wrote. "Widening this section is necessary to maintain an acceptable level of safety and service."

Hoffman has pushed on. While she waits for a verdict on the fate of the trees, she is trying to do whatever she can to protect them. The trees are suffering slow strangulation from four varieties of creeping vines, including poison ivy. She has been writing to newspapers, trying to stir up interest from volunteers who would clear the vines.

A year ago she actually managed to round up a small crew to cut the vines around three of the trees, using pruning tools the county lent her.

Even her effort to recruit troubled youths to prune the vines was rebuffed. Zulema Wilson, in charge of the state-sponsored juvenile justice program in the county, said the project "lacks full relevance" and, with the poison ivy, posed unacceptable health risks.

"This is not a risk the program wants to take," she wrote. "Lastly, both team coordinators have severe allergies."

When Hoffman recently sought funds from the "Adopt-A-Road" program, the county Department of Public Works said it's only for citizens who donate their time to pick up trash and litter, not to save trees.

"If Ms. Hoffman would like to formally adopt a section of Old Crain Highway, we would be glad to post signs in accordance with the program to recognize her efforts," Public Works Director Betty Hager Francis wrote.

The tall trees, however, are not only scenic; they are rooted in local history. They were seedlings transplanted from St. Mary's County by the Forest Garden Club, a group of Marlboro society women, at the behest of the late Judge Charles Clagett Marbury and his sister Katherine Marshall Marbury Clagett.

These descendants of John Marshall, the fourth chief justice of the United States, lived in Weston and Beacon Hill, two plantation houses off Old Crain Highway that continue to be occupied by family members.

Like Rose Hoffman, they care about the trees. "My uncle and my father's wife planted them," said Hal B. Clagett, a retired lawyer who grew up at Weston. But the county plans to spare the trees on their side of the road, and the Marlboro gentry has largely deferred to Rose Hoffman.

The importance of the trees has been duly noted in the adopted master plan for the Marlboro district, but the county highway plan also includes upgrading the road to meet projected growth in traffic.

In fact, the county planning director urged the departments of transportation and public works to forgo the road widening and leave the trees, but the answer was no, that the developer had to take them down for safety's sake.

"It's totally unnecessary," said S. Robert Kaufman, a vice president of Michael T. Rose, the developer. "We like to save trees. The road widening will contribute to people driving much faster because there'll be a lot more pavement."

Rose Hoffman has her allies, if not yet a victory. County Council Chairman M.H. Jim Estepp (D-Upper Marlboro), who has submitted inquiries to the bureaucracy on her behalf, recently called county officials, without Hoffman, to his office.

At his behest, the county will call in a certified arborist to determine which of the vine-choked trees can be saved, with or without the road widening. He also introduced a resolution in the council making Old Crain Highway an official "scenic highway." It could offer some protection for the cherished cypress--or maybe not.

But of Rose Hoffman, Estepp said this: "God bless her. She's bound and determined. We need folks like her to persevere. One person can make a difference."

So Hoffman is undaunted. She sings a few lines of the old Fred Waring song, "Green Cathedral," one of her favorites. She recites the Joyce Kilmer evergreen about trees: "I think that I shall never see a poem lovely as a tree." And she gets ready to write another letter.

CAPTION: Rose Hoffman, 76, touches a bald cypress tree. Hoffman is trying to save about 40 cypresses in Upper Marlboro.