What is one limitation of the morphological species concept?

The morphological species concept has several limitations, one of which is that it cannot be applied to organisms that reproduce asexually. This is because asexual organisms do not have two distinct sexes, and thus do not have the same reproductive barriers that separate sexual species. As a result, it can be difficult to determine what constitutes a species in asexual organisms, and the morphological species concept is not always a useful tool in this context.