These magical arrows absolutely refuse to fight.  Once placed in a quiver or container with a character's regular arrows, they will transmute themselves to look exactly like the other arrows.  Their difference will become obvious as soon as an archer attempts to use them.  When one is fired, it will vanish only inches before striking a hostile target (doing no damage to the target).  Since the cursed arrows have changed their appearance, it should be impossible to separate the mundane from the magical without a detect magic spell (and not even then, if the cursed arrowes are in the same container with other arrows).  Twenty percent of these arrows will not vanish, but will turn into daisies just before reaching their destination (also doing no damage, of course, unless the creature has an allergic reaction).

Source:  Dragon Magazine #77, 1983, page 21