Unfortunately, they cannot grow on corpses or animals, only on century old trees.
The Winter Ice herb grew in desserts, contrary to what it's name might imply. It's affects were similar to Shen Tianyu's Samhain poison that she had tried to sell in an auction before. However, the affects were weaker and the duration was also shorter. It merely causes the victim to feel like their blood had frozen for a moment, which usually caused them to pause. It had to be combined with some other herbs to actually make it useful in the battlefield.