Use the following plants to craft the corresponding healing item. Note: You do not need to be injured to do so.

Harvest the Cattail.

Harvest the Old Man's Beard Lichen, craft a bandage with it (3 Herbs and 1 Normal Bandage), then use it through the "First Aid" menu.

Harvest Rose Hips, make a Tea with it in a fireplace (25 Rose Hips and 0.25L of water), then use it through the "First Aid" menu.

Harvest Reishi Mushrooms, make a Tea with it in a fireplace (3 Mushrooms and 0.25L of water), then use it through the "First Aid" menu.