The Crow; The Crocus

Some are unable, as you know,
To tell the Crocus from the Crow;
The reason why is just be‑caws
They are not versed in Nature’s laws.
The noisy cawing Crows all come,
Obedient to the Cro’custom,
A large Crow Caw‑cus to convoke.
You never hear the Crocus croak!