The variety Mochidaruma has rectangular epidermal cells at least 50 micrometers thick. Parenchymal cells are either globular or elliptical in shape and 30 to 60 um in diameter. Up to 20 suckers can emerge from axillary buds located in leaf petiole nodes on the basal part of the rhizome. Mature petioles are vertical to oblique 30 - 50 cm long basally flattened and surround the rhizome. Eighty percent of the petioles are thrust in a right hand orientation.
Flowers are typical Cruciferae.
Seeds are borne in siliques that are short, linear, oblong, torulose, cylindric with membranous valves and without a midrib. Storage outside of a cool moist environment will result in desiccation and death since wasabi seed is temperate and recalcitrant. In the summer and winter only 2 or 3 new leaves grow per month since growth generally slows or stops during periods of temperature extremes. From March to June and in August an average of 5 to 6 new leaves per month will appear. In Japan, flowering begins in, January, peaks in April and is finished by May.