Magical item. Sort of.
These unassuming beans can be tossed on to any surface (including water, oil, walls and so on) to form a trap for any unsuspecting creature.
Hilda van Hoffman was a mage and botanist with a huge interest in magical plants. Her experimentation with the beans came after an unfortunate encounter with Assassin Vines. To Hilda’s great regret, she was unable to save the original vine, but her experimentation with various versions of the plant led her to the beans. Eventually.
In one notable instance Hilda herself was said to have used her beans as a means to keep afloat when her ship ran aground on the Trackless Sea.
20 beans can cover one square.
A creature moving across the beans, even in water or on oil, must succeed on a DC 10 Strength saving throw to get out of the vines that sprout from the beans when someone walks or swims across them.
Once the beans are used they wilt and can’t be used again, but there is a 30% chance that the beans sprout and grow 1D4 beans after a week, provided they have access to soil and clean water.