Invisible walls my friend and I drew in her yard shaped much more than pretend rooms.

Perhaps the scent of longleaf yellow pine accounts for my memories of playing in Hettie's front yard some 40 years ago. Smells will do that.

Hettie was over a dozen times my age but the finest next-door neighbor a 5-year-old could want, and I preferred her yard above all places on earth. Beneath a stand of 30-foot pines, Hettie and I would sit in her great wooden lawn chairs and talk. After a while she would ask didn't I think the pine trees smelled fresh. Then, rising from her chair, she'd get a rake and motion for me to come along.

Now Hettie understood that certain pines were a superior resource for the task she had at hand. The longleaf variety in her yard produced the longest needles of her yard produced the longest needles of all the Southern conifers, and Hettie recognized their unique property.

First she would rake together a small mound of brown needles. I would scoop up handfuls and add to her pile. Then, propping up her rake against the scaly bark of a nearby pine, she'd say, "We're going to make a pine straw house. Now where would you like the kitchen to be?"

I'd locate a spot where sunlight filtered through the branches above. As though the rake were her enormous pen and the straw her ink, she would begin by drawing the outline of our kitchen. By late afternoon our two-dimensional architecture covered a vast portion of the yard with rooms of assorted dimension and utility. We'd walk through the spaces, always careful not to violate our invisible walls.

For furnishings we would find wooden crates, cushion them with pine straw, and cover them with old pillowcases or flannel blankets. Then we'd spread a dish towel over a cardboard box, and Hettle would produce a child-size tea set from indoors. There would be peanut butter cookies and sweet iced tea, and the world would be right.

The next year I started school, and after that I rarely visited Hettie. When I reached the second grade she and her husband moved away, and a family with three children came to live next door.

Amy, the youngest of my new neighbors, was 4. Her older siblings and I rarely allowed her to play with us. But one fall afternoon as I approached my neighbors' house, I noticed Amy alone beneath the trees in the front yard. She was just standing there pouting and prying loose a piece of bark from one of the old pines. I knew she would get all sticky with the resin, so I parked my bike and started toward the tree to tell her to leave it alone. A gust of wind suddenly lifted and swooped the needle brushes overhead. The air felt like breath exhaled by the longleaf yellow pine. Its redolent scent refreshed memories of Hettie and the invisible walls where I'd played a few years before. I paused to reconsider my afternoon plans.

"Come on, Amy," I said, as I looked around the yard for a rake. There wasn't one, so I began gathering pine straw with my hands. She watched as I placed a small mound near the feet, and I saw the pout on her face become a question.

"We're going to make a pine straw house," I said. "Now where would you like the kitchen to be?"