I haven’t grown that one ....several others though...but I see a root and a new growth tip startIng. My thought would be to dust it with cinnamon ..moisten some potting soil, not wet just moist....and plant it loosely in a pot in the shade and don’t water till you see some growth. Sometimes once they start to rot though it’s tough to stop.

You don't say where you are or which sort of climate you're in. Don't water it until it shows growth. There's a number of Amorphs that generally go through a dormant period during the dry season. The dormancy usually breaks before the wet season sets in. Because of the hollow in the top of the tuber, if you water too early water pools in that hollow and causes rot. The suggestion to dust the top with cinnamon powder is your best bet for recovery.

The (Napalensis) did have about 3/4-1 inch growth tip when I planted them, which then rotted off and I cleaned off. I didn't plant early, I didn't get it until recently. I assumed it was ready to grow the same as Konjac, all of mine is growing now in the ground. I also have one Bulbifer growing in a pot. I planted one Napalensis in a pot exactly like I grow the Bulbifer, and the other in the ground.

I live zone 6/5b. It has been hot the last couple of weeks.

Thanks. I put cinnamon powder on top, and put in a pot on my porch in the shade. No water except from ambient humidity. I won't water unless I see a pointed stem.

Still trying to learn about these types of plants. Here a couple of Konjac that flowered in my basement last March, and the Venusom "forest" behind which I cleared more than a dozen large tuber "bulbs" in Spring. Not sure I would call Venusom a weed yet, I'm still amused that they grow like a zombie horde in the worst places, multiplying exponentially if they have space.

They're a very interesting group of plants. Venosum is a Sauromatum rather than an Amorphophallus, although closely related. I have the closely related Dracontium amazonense and Typhonium johnsonianum.

Bulbifer have all those bulbils on the leaf as well as seeds after flowering which are spread around by animals. I pulled out well over 100 plants the previous year. Last year about 70 - 80 removed. Hopefully this coming season I'll get the rest. Never suspected they'd get away so fast.

Other than that I have Amorphophallus: titanum, symonianus, konjac, variabilis, paeoniifolius, galbra, plus 3 unidentified one of which I think is napalensis.

Wood ashes, after digging out the rot, pack it with wood ashes.