FLOWERS OF THE COUNTRYSIDE, by Philip and Marjorie Blamey, with illustrations by Marjorie Blamey (Morrow, $25.) This is what a book on flowers should be -- delicate illustrations surrounded by a text that is informative and gossipy, loving the lore as well as the flowers and concerned with changes in the countryside that have led too many flowers onto the endangered list. The country the Blameys write about is England but the concerns -- and many of the flowers -- are also common to the United States. In addition to standard botanical information, the Blameys manage to include in their text a delightful floral sideshow. For instance, the seed of the common poppy produces an oil for mixing oil paints, feverfew was the aspirin of the 16th century and the 17th century produced a lethal curiosity known as a "Children's Necklace for the Teeth," a teething ring composed of roots of the poisonous Henbane Orphine and Vervain, cut into beads, strung into a necklace, soaked in red wine and rubbed dry with red coral and powdered peony root -- a pacifier which, if indulged in too long, would surely have led to the ultimate pacification. BENINGFIELD'S COUNTRYSIDE, by Gordon Beningfield (Viking, $19.95). Gordon Beningfield's paintings of Dorset and Hertfordshire are lovely, dreamy things -- an apple orchard in snowy bloom, a fox running toward a hedgerow, pigs squishing happily in a muddy field, field mice sitting in a rose bush -- the flora and fauna of southern England painted and described by a man whose text is as personal as his paintings. It's a book to turn to when city life becomes unbearable and comfort comes from the sight of a water mole perched in furry concentration in the crook of a tree or in the story of one of the last of the traditional shepherds. HEDGEROW, by John T. White, illustrated by Eric Thomas (Morrow, $13.95). A book on hedgerows seems, on the face of it, a very specialized thing, a gift for somene who agrees with Robert Frost that good fences make good neighbors. Instead, the authors place the hedgerow at the center of rural life in England, tracing its history (it got its name from the Saxons and its plantings from the Normans), its usefulness to villagers as a source for food and firewood, and its role in such local superstitions as the one that holds that on Michaelmas Day, the devil spits on the blackberries, after which they are inedible. The hedgerows were created by splitting young hawthorns and bending them over until they grew together in an impenetrable and thorny barrier. The very denseness of the hedges has made them a haven for wildlife and a variety of wild plants. Like other writers, the authors are concerned with the disappearance of the hedgerows and what this means to the creatures and plants which have nested there; they supply a list of plant materials for anyone who wants to reverse the trend. An odd book, aimed neither at the botanist, the gardener, nor the historian, its simple direct text might appeal to an older child, who would also be delighted by the lavish illustrations. THE ENGLISHWOMAN'S GARDEN, edited by Alvilde Lees-Milne and Rosemary Verey (Chatto & Windus, $24.95; distributed by Merrimack Book Service, Lawrence, Massachusetts). There is one other thing that is disappearing from the English countryside: the gardener. But perhaps his loss is not to be mourned for in his place we have the lady, of manor or cottage, up to her elbows in humus and compost, ripping out bindweed, plunking in plants and bringing an altogether personal and occasionally eccentric charm to her garden. Each garden in this book is pictured in beautiful photographs and described by the woman who created it. "Herb gardens bore me, I can't bear modern roses, and I dislike the trend of enlarging flowers that are already large enough," writes Lady Anne Tree, whose preferences are expressed in equally decided fashion. "In late summer the kitchen garden is the only area I like. The main part of the garden is short-lived in its full beauty, and by the end of July all the beds have an untidy, hairy look," complains Lady Caroline Somerset with an exasperation familiar to all gardeners."What makes me a really happy woman," she writes, "is to go round some garden which I think is wrongly constructed, planted in bad taste and rather untidy. I am then extraordinarily civil to the owner, say how beautiful everything is and go home in a highly contented frame of mind. I am not a nice person." Ah, but who cares when she is as happily knowledgeable and opinionated as the other women chosen to lead the lucky reader down the garden path.