Thorn Magic

Thorn Magic (known also as Way of Thorns) is a darker version of Leaves Magic, traditionally identified as a part of Black Magic, with Life Magic and Poison Magic being its secondary attunements. Its hexes allow not only for fast growth of plants, but also to... 'change' it.
In short - the effects are poisons, thorns, carnivorous plants, or even ones that can use low level black magic/poison magic to paralyze enemy to then slowly devoured him alive... or dissolve him in acid and then suck through some small tubes... it is a purely offensive and particularly deadly magic, that due to its generally low level of humanitarism is considered a Black Magic.