What is the difference between Big Wolf Grass and Needle Bidens?

Bidens mandshurica and Bidens bipinnata are two recommended types that are difficult for people to distinguish, so what is the difference between Bidens rubescens? 1. The difference between Bidens rubescens and Bidens bipinnata L. Stem: the stem of Rabdosia rubescens is nearly round, and the stem of Bidens bipinosa is obtusely quadrangular; 2.