Darkseed

Masters of the Wild: A Guidebook to Barbarians, Druids, and Rangers (MW)Updated Supplementals (3.0)

Darkseed is a D&D 3.5 spell (Transmutation) from MW. Range or area: Close (25 ft. + 5 ft./2 levels); Saving throw: Reflex negates; Duration: 1 day; Casting time: 1 standard action.

School
Transmutation
Casting Time
1 standard action
Components
V, DF
Range
Close (25 ft. + 5 ft./2 levels)
Target
One normal plant or plant creature
Duration
1 day
Saving Throw
Reflex negates
Spell Resistance
Yes

If the target fails its Reflex save, it takes 1 point of damage when the spell is cast and another every hour while it is in effect.
Hardness is ignored for damage from darkseed.
It would take weeks to kill a large tree with successive applications of this spell, but a small plant would die in a matter of hours.
Darkseed does not affect plant creatures with Wisdom and Charisma scores.