a solid bulblike enlargement of the stem of some orchids
造句
There are a large number of starch grains in most cells of protocorm and in cells of cortex parenchyma of rhizome, but almost no starch grain is found in pseudobulb. 原球莖的大部分細胞都含有淀粉粒，根狀莖的皮層細胞含淀粉粒，而假鱗莖幾乎不含淀粉粒。