Young Guinevere

In a rather long text for the picture book format, San Souci ( Feathertop ; Young Merlin ) draws on an amalgam of sources to portray the young princess as she explores the enchanted forest around her father's castle and as she ultimately saves the kingdom from destruction. All the ingredients prized by fantasy aficionados are here: the prophecy of Guinevere's marriage to Arthur, the unicorn in the woods, the hideous monster Guinevere outwits, the heraldic splendor of the battle for control of England, the heroine's brave journey to summon her future husband to arms. Although the extensively researched text evokes the glamour and danger of legends of the Middle Ages, it occasionally becomes self-consciously weighty. As a result, characters are little more than stock gothic types, which befits the grand scale of oral epic but is ill-suited to the more intimate scope of a picture book. Henterly's ( Good King Wenceslas ) lavish full-page artwork in rich jewel tones is, like the text, best when confined to small detail work. The exquisite spot illustrations embody all the beauty and delicacy of the tapestries they are meant to suggest. However, the sweeping large-scale paintings may appear overly commercial for some tastes, conjuring up visions of florid romance novel covers. Ages 7-11. (Mar.)