The hhcc plan monitor (sold as "Mi Flora") is a device you put in a flower pot to monitor several parameters (such as temperature, moisture and brightness)
The flora plant monitor is a flower pot monitor. They seem to use the proprietary authentication mechanism.
As i don't own this device, i didn't reverse engineer it, but you can find more informations here Also check out https://www.open-homeautomation.com/2016/08/23/reverse-engineering-the-mi-plant-sensor/