Jagra draws a flask and throws it at the tree (this one isn´t dead, by the way). It (the flask) shatters in a ball of fire, and starts burning furiously. The other three "fruits" hanging from the tree also fall as soon they feel the heat, sprout tentacles and quickly scurry into the jungle.
Meanwhile, the sailor´s arm, with the "fruit" attached, fall limp. (he still has the arm, just seems that he can´t move it) Amira doesn´t remember anything about that thing, so it may be, perhaps, a natural -though bizarre- animal. Al-Khazad reaches the sailor, and sinks his dagger in the thing without problem; it almost explodes in a burst of blood: apparently, it was being sucked from the sailor´s arm.
The tree just stands still and burns stoically.