The lowly or common associating with the noble or talented, often used to express a sense of personal inadequacy in comparison.

他自谦才疏学浅，与教授同行如同蒹葭倚玉树。

The weak seeking help, support, or protection from the strong.

这家小公司依附于跨国巨头，不过是蒹葭倚玉树罢了。