Genshin Impact is filled with all sorts of different remedies that you'll need to gather for various reasons. You may need them for quests, to level up weapons or characters, or to craft. One of the many plant types in Genshin Impact is the Mist Flower Corolla. This icy plant will grow just about anywhere, but can often be found near bodies of water. When you first find this flour, you won't be able to harvest it, and it will cause you cold damage if you get close.
You'll need to hit the flower with a Pyro ability to thaw it, and only then can you add it to your inventory.
A great place to harvest them is at Dawn Winery in southwest Mondstadt. This area is, unsurprisingly, known for wine, but it's also teeming with ice creatures and ice plants, including mist flower corolla. On the shores of lakes and rivers in this region, you will find many mist flowers growing.
The main thing to keep in mind for all of these games is to collect these items as you find them. If you see a new type of plant in the world, figure out exactly how to harvest it, then add it to your inventory. This will save you a lot of time when the game hits you with a fetch quest like this.