Organic Arrows

Your arrows are smooth & you've compressed these as they go further away from viewer so they can flow through 3d space nicely. Did you skipped on the lineweight for these arrows? You're supposed to do lineweight(after ghosting for them & with shoulder) to show which side of the arrow is facing the viewer near the curves. Be sure to do them in your warm ups.

Leaves

Nice work on maintaining the flow of leaves(also in their veins & the folded ones). The edges of leaves are done individually as intended.

I feel like you could've done some more leaves here as there is enough empty space.

Branches

You've kept ellipses perpendicular to the flow line along with changing their width gradually. Sometimes the edges of these branches are leaving visible tails, it's natural at first but with more ghosting & practice you can improve on having them overlap with adjacent edges nicely.

Plants

I see that you've included the demo plants, it's not bad if you've followed the reference but with next lesson I suggest doing more non-demo constructions.

In the 1st plant drawing, I see that you forgot to connect the curve for the petals near the top, take time for each petal(,etc) so you don't miss out on them in future.

In (2nd plant drawing)Mushroom, your ellipses are good but you should've drawn it with the minor axis as it would've improved it's vertical stability quite a lot.

Nice work on keeping the parts of plant enclosed in it's planned ellipse.

Your attempt on the shadow casting is really good as they wrap around the forms(like in the potato plant). In the next drawing, it is kind of overdone but still good try.

Overall you've done great job on these exercise, we need just little more variations in these plants as most of them are from the demo & also because this is a late critique you could use some warm up for these plants.