No, plants cannot be relied on globally for directions. But they can give you hints sometimes.
The only thing plants can tell you is in which direction the sun typically shines from. This isn't especially useful to you all the time when navigating, because in most situations you don't have to ask the plants where the sun is, you can just look up and see for yourself. The sun has been used for navigation for thousands of years.
In situations where you can't always see the sun, like in tall dense forests, the plants typically point straight up towards the canopy, or in all directions so they can gather as much ambient light as they can, so they aren't exactly useful in those situations.
On days where it's clouded over with dark clouds, you may go days without seeing the sun. In this situation you could use the growth on the ground to help you determine from which direction the sun typically shines. Some species of flowers for example move like solar panels so their faces are always directed towards the sun. Even on a cloudy day they'll be doing their best to track where the most rays are coming from. Some species of flower can even remember from which direction the sun rises, and at night re-orient themselves to face the direction they know the sun will rise.
You're not going to find many plants that can be consistently relied on to help you navigate, but they can help you avoid getting turned completely upside down.