The wood of a quarterstaff, javelin, spear or polearm touched is transmuted to the spring-like wood of a male yew tree. For the duration, you can use your spellcasting ability or Constitution instead of Strength for the attack and damage rolls of melee attacks using that weapon. The weapon gains a +2 attack bonus against enemies using a shield, shield spell or are using the dodge action as the now flexible shaft bends around defenses to strike the enemy and the weapon does an additional 1d4 poison damage from the toxicity of the male yew. The weapon also becomes magical, if it isn't already. The spell ends at the end of the turn the wielder lets go of the weapon.

This transmutation can be extremely dangerous for the caster, poisoning themselves in the process. When the spell ends the caster must make a constitution saving throw DC 10 or be poisoned from the toxicity of the transmutation for 1d4 poison damage (at 5th level CON save DC 11  or be poisoned for 2d4 poison damage; at 11th level CON save DC 12 or be poisoned for 3d4 damage and suffer a level of exhaustion; at 17th level CON save DC 13 be poisoned for 4d4 damage and suffer a level of exhaustion.)

This spell’s damage increases when you reach higher levels. At 5th level, the melee attack deals an extra 1d4 poison damage. Damage rolls increase by 1d4 at 11th level and 17th level.