Harrietum Officinalis allows you to temporarily transform yourself into an animal. At the moment, the only animal available is the male. To transform you must find the herb and have it in your inventory before interacting with the transform location.
It is harder to find the grass than expected. After the cutscene with Harriet, you think the grass would be visible and around her tent. This instinct is not. Grass is scattered around the map like any other plant. Cartographer Jean Ropke already has an option for Harrietum Officinalis locations on their RDO Map.
The plant is common in New Hanover, West Elizabeth, and Ambarino. Some are scattered across northern New Austin, but you won't find much, if at all, south of Hennigan's Stead. While Grizzlies have a lot of plants, there aren't any north of this mountain range, so don't worry about going too far north. There are a few places in Lemoyne, but they are not common there.
Screenshot via RockstarThe best places to look aren't around Harriet's tent pitches. Instead, the plant is easiest to find along the Kamassa River in the Roanoke Ridge portion of New Hanover. There are other places, but the plants here are clustered and arranged, so traveling to get them isn't too difficult. The problem with this location is that it is very far from the processing area and it will take a lot more work to get back. You can get the items quickly, but it's not efficient. The factory is around Big Valley and Tall Trees in West Elizabeth, and it's closer to Harriet. But the spawning plants are more distant from each other.
Plants can only be found once per day, like collectibles. They will likely be reset when the collectibles are reset. They don't reappear when exiting the game or switching sessions, like normal herbs would.
You need five Harrietum Officinalis to transform. So your factory inventory will go fast.
Screenshot via RockstarHarrietum Officinalis glows gold, like collectible flowers, so it stands out among other more mundane herbs in the game. However, it does not have an audio signal like collectibles. We found it to be harder to spot than the average plant from a distance, but once spotted it is easier to recognize.
Like most herbs in the game, you can carry up to 30 Harrietum Officinalis. You need three to five to start a transformation. The transformation only takes five minutes but can be extended if you have more of the factory in your inventory.
Unlike many other valuable herbs in the game, Madame Nazar does not store Harrietum Officinalis.
