Common scab symptoms are variable and can range from surface russeting to deep pits in root and tuber vegetables.

Some species have woody roots while others have starchy tuber-like roots which can be eaten like tuber vegetables such as potatoes or made into flour.

One, with the fanciful name of yama fugu (literally, mountain blowfish), turned out to be fresh konnyaku, a tuber vegetable, displayed as sashimi blowfish often is, in gossamer-thin overlapping slices.

Root and tuber vegetables are susceptible to infection by Streptomyces species as soon as the root or tuber forms, but, because this disease only affects root and tubers, the symptoms are not usually noted until harvest.

En's ootoro konnyaku (quivering, shimmering slices of celadon-colored aspic made from a tuber vegetable and speckled with ao nori sea herb) was served with shredded and minced herbs on a bed of crushed ice with a tart, pale miso dipping sauce.

We both enjoyed our $23.35 kisetsu zen (seasonal tray), a filling meal that began with a plum wine aperitif served with a batter-fried, meat-stuffed pocket of konnyaku (a gelatinlike loaf processed from a tuber vegetable) and concluded with a dish of sweet black-bean ice cream.