In Saitama, arrowhead is grown in the low, wet ground along the Ayase river in the southeast of the prefecture, on land that was never any good for growing rice. Koshigaya, Soka, and parts of Saitama city.

The calendar for growing it is extremely tight. Seedlings go into the paddies in late June or early July, and the harvest runs from the very end of November through December. That is the entire window, and there is nothing outside it.

What makes the tuber worth all of that effort is the shoot it puts up. Kuwai sends up a single large, long shoot, and a shoot emerging is auspicious in about the most direct way anything can be, so this vegetable belongs firmly to the New Year table. There is a second reading in which the arrangement of the tubers suggests a mother nursing an infant, and from that come wishes for descendants, for health, and for rising in the world.

That is a great deal to load onto one small corm. Simmered, it is cooked together with gardenia fruit, which turns the flesh a bright, clear yellow. And the shoot is never trimmed off before serving. It goes onto the tray still pointing upward at the ceiling, which is the entire reason for putting the thing there in the first place.