块茎

At the stage of tuberization to tuber-expanding, the growth of leaves, stalks and tubers reached the maximum.

块形成到块膨大始期，阶段吸硫量和吸硫达到最大值，成熟收获时降到最低值。

Stem with much reduced leaf blades that function as rhizoids below ground, with or without tubers or rhizomes.

在地下面，起假的作用的具非常退化叶片，有或没有块或状。