Sprigs of mistletoe fact and fancy--everything from the plant's parasitic growth patterns which can damage and eventually kill host trees, to its more benign function in legend where it is associated with good luck, resurrection and, of course, kissing. Poole says that according to an ""ancient Hebrew biography,"" Christ's cross was made from a mistletoe tree (the story we know says dogwood) and she mentions a scientist, Dr. Alfred Weinheimer of Oklahoma, who is experimenting with mistletoe as a cancer cure. Or, if you prefer to think of mistletoe as a Christmas ornament, there are directions for constructing a traditional kissing ball. The narrative bunches all these aspects together in awkward chopped-up paragrpahs that make background facts, humorous asides, and topic sentences difficult to tell apart. Avid harvesters of plant lore won't be deterred but the flat retellings of myths and superstitions are unlikely to cast any spell on the casual passerby.