It once had the reputation of being a girlish kind of art - too "pretty," not serious - and there's still a lot of schlock out there. But classic botanical illustration bears no resemblance to those flower pictures you see on powder-room walls.

The real stuff is pure, exquisitely natural, and true to life, pulling you deep inside the ruffly petals of a pink parrot tulip or the velvety throat of a plum-colored foxglove.

"It's a fine art, and it's beautiful," says Louisa Rawle Tiné, who teaches botanical illustration at the New York Botanical Garden and at Chanticleer in Wayne. (For years, she taught at Longwood Gardens in Kennett Square.)

Natural beauty is easy to appreciate. But if you're a gardener, you're positively transfixed before one of these illustrations, staring at the lines and dots, maybe with a magnifying glass to distinguish every dab of watercolor, every stroke of colored pencil.

And it isn't only about aesthetics. Botanical illustrators also need to know the science of plants, their parts and their seasons, and have a command of technique and composition.

"Your work has to be accurate as well as beautiful to be considered really good," says Tiné, who grew up in Bryn Mawr and now lives in South Salem, N.Y.

The desire to learn, and have fun doing it, draws 11 artists to a recent weekday class at Joan Frain's home in Exton. Frain, a botanical artist and instructor for almost 30 years, may teach the only ongoing class in the area; she's had some of these students for more than 15 years.

They're nurses, biology teachers, college administrators and custom framers. And on this particular day, they're drawing purple coneflowers, black-eyed Susans, orchids and thistles, goldenrod and carnations, which they've examined and photographed every which way and then some to get them just right.

They've bought flowers from the Acme and specimens from the nursery. Many, like Linda Kneeland of Worcester, are gardeners who mine their own backyards.

Kneeland sits at a table off Frain's kitchen, intently drawing a cosmos from her garden with colored pencils. She prefers pencils, she explains, because they give her more control and are easier to work with than watercolors.

"And watercolors gave me the equivalent of writer's block," she says.

Kneeland's cosmos has an elegant aspect, perhaps because it's white, and it's drawn - as is customary with botanical art - on white paper.

"How do you get the white of the flower to show up?" she asks. "Joan says to use blue and green on the stem. It reflects color."

Kneeland, president of the 70-member Philadelphia Society of Botanical Illustrators, finds drawing her cosmos - taken from the Greek word for harmony or ordered universe - as relaxing as a meditation.

"You sit down and let everything else go away. It's very satisfying," she says, readily pointing out the imperfections of her work.

The stems shouldn't be exactly parallel. And one of them isn't clearly visible. But, Kneeland says, "I just did this for fun."

A few seats away, Mary Tipping of Chadds Ford is working on an orchid and being very intense. Figures. She can't sleep if the bedsheets are crooked or "the checkbook's one penny off."

Tipping turned to botanical illustration after taking a frustrating class in landscape painting.

"It was too broad. My mind doesn't work that way," she says.

She clearly likes this better.

"I love the detail," Tipping offers, eyes glued to her orchid study.

Imagine the effort required, even to collect specimens, by botanical illustration's pioneers.

In the first century, Pedanius Dioscorides, a Greek botanist and physician, had to travel all over the ancient world to gather plants for his meticulously drawn five-volume work on medicinal herbs. Called De Materia Medica, it remained in use, reproduced in manuscript, until the 17th century and is considered a precursor to all modern pharmacopeias, or medical compendiums.

Beautifully illustrated plant books followed in the 18th century, the field's golden age, with botanical illustrators - mostly men until the 19th century - enjoying the favor and patronage of wealthy Europeans.

Today, Tiné says, botanical illustrations are commanding impressive prices in England, where the art has always flourished. Interest in this country also is on the upswing, she says, citing the 500 artists a year who take a botanical illustration class at the New York Botanical Garden.

Twenty years ago, "it was only a handful," says Tiné, who teaches a class in the history of the art.

For the handful back at Frain's house, the teacher is moving from student to student, offering encouragement and wisdom.

"If nothing outside inspires you, look in the refrigerator," Frain says, prompting calls for carrots and eggplants, and "embrace imperfection. That's how it is in nature." Which all agree is a good thing.

But earning a living at this, as Frain and Tiné have done? Not a terribly realistic thing.

There isn't much call in the workplace anymore for botanical illustrations, though they are sparingly used in some scientific research, in a few seed catalogs and publications such as Martha Stewart Living and Horticulture, and for high-end greeting cards and textiles.

Sometimes, it's a struggle to educate others.

"When people hear the word illustrator, they think you're more craftsman than artist," says student Pat Gregg of Mendenhall.

And what about the folks who mean well but drive these artists crazy by asking, "How come you didn't paint your flowers in a vase?"

"They really want a Chianti bottle and a checked tablecloth in there," Frain says.

Contact gardening writer Virginia Smith at 215-854-5720 or