April 2020
The Taro Plant (gives Taro Root), which is included in the "Island Living" game pack, is not included in the collection list for Gardening.
I am using a Playstation 4, but I highly suspect this is true on all platforms.
The main reason why I bring this up is I've discovered that it is not listed in many lists you can find online that claim to be a complete collection of plants available in "The Sims 4", and I believe it is mostly due to it not being included in the collection list, which I also believe is a simple oversight.
April 2020
Hello
I play on PS too, and I have it
It looks like a brown potato and is just before the superfruit. i play in french, but I don't know if it counts