What type of spell does each flower from preserved seeds cast?

Question

Podzilla creatures (rootthings and quaras) drop preserved seeds that can be used in the battle against The Rootkraken:

• Preserved Purple Seed
• Preserved Dark Seed
• Preserved Light Blue Seed
• Preserved Pink Seed
• Preserved Red Seed
• Preserved Violet Seed
• Preserved Yellow Seed

When you plant a seed in a tile with fertile earth, a flower of its respective color appears and starts casting spells for a certain time. 

I would like to know the type of spell each flower cast, so I can know which ones are the most useful in the fight against the boss.

Answer 1

You can see the seeds attacks on Tower Defense task.

I think the only one you can't see is the Dark Seed

Most usefull: Violet, Pink and Red