So just to start, since it's easier to address this as a response to your own comments rather than in the critique itself, you mention that you employed non-textural shading (via cross-hatching). Within the context of these lessons, this is indeed incorrect, as explained here back in Lesson 2. To put it simply, we don't put anything within these drawings that doesn't serve a specific purpose. Shading is usually used as a way to make something seem three dimensional, but we already have more effective means to do that through constructional techniques. Therefore shading just becomes decoration - something superfluous that we are not dealing with throughout this course. As such, you should be leaving it out of your homework here. The main exceptions are where the surface itself actually doesn't have a texture - that means the artificial forms like basic boxes from the challenges, the arrows, etc. In those cases the hatching helps us make sense of how that form exists in space, especially when drawing through things.

With that out of the way, let's move onto the critique. To start your arrows are drawn quite well, flowing both smoothly and fluidly, and capturing a nice sense of movement. I am noticing however that as we get farther back, the spacing between the zigzagging sections doesn't seem to compress consistently with the foreshortening of the ribbon's own width, and you tend to randomly increase it right at the end there. Pushing that compression of space harder will help capture a greater sense of depth, that you're only just barely missing.

Moving onto your leaves, you're doing a good job of constructing these both in the application of successive constructional phases, and in capturing the fluidity of the more basic form. Of course, you've ended up falling onto generic hatching where you could have alternatively actually dug into texture instead, so as mentioned before, be sure to avoid that in the future.

Your work on the branches is generally well done - you're overlapping your segments well so as to transition smoothly from one segment to the next, although you do have a number of places where you haven't quite extended a given segment fully halfway towards the next ellipse (as demonstrated here). Extending fully halfway helps provide enough runway to make that transition as seamless as possible. Also, you've got a couple places where you don't quite keep the width of the branch consistent, though most of the time you do a good job of this. Consistent widths helps maintain the simplicity of the form, which in turn makes it more believable as a 3D structure.

Stepping through your drawings, you've largely done a good job with a few things I'd like to point out.

For your hibiscus, a minor point - don't attempt to capture anything that appears to be a "local" colour. That is, the actual physical colour of that surface, like you did towards the center of the hibiscus. Reserve filled black areas for cast shadows only, as anything else will risk flattening out the drawing, due to outright obliterating important spatial information that the viewer's eye needs to make sense of the drawing. Cast shadows are okay because of how their resulting shapes actually themselves help provide the viewer with information about how the object casting the shadow relates to the surface upon which it is cast, but creating an arbitrary black void in the center of your flower makes things much more difficult to parse. You've got a similar issue in this alpine strawberry plant, where the fruits are completely flat due to them being filled in.

On your bunny ear cactus, this issue is actually my fault due to how the demonstration was done (it's rather old now, and needs to be redone to better reflect the current stance on how texture should be approached). Just remember that as discussed in the texture section for lesson 2, instead of outlining our textural forms - that includes both the nodules on the cactus' surface and the pebbles along the base - we only want to imply their presence by drawing the shadow shapes they cast on their surroundings. Also, watch the initial shapes/forms you laid out for the pebbles. Since you outlined them, they're employing constructional techniques, and therefore the complexity there severely undermines their intended solidity. That's less of a concern when dealing with textural techniques, so you've caught yourself straddling between two different strategies. That all aside, I don't think the pebbles quite look like that, so you'll want to make a point to observe your references more carefully before putting down each and every mark.

The pitcher plant is largely well done, with one minor point. Where the mouth of the plant curls back and folds over itself, you seem to have helped clarify that overlap through the use of line weight. That is technically fine, although line weight should generally be reserved for more subtle adjustments in thickness that appeal more to the viewer's subconscious than their immediate awareness. Instead, employing cast shadows (which fall on the underlying surface, their size generally being relative to the distance between the form casting the shadow and the surface receiving it) are better suited to this sort of thing. Right now it looks like you're caught between line weight and cast shadows, attempting to do a little of both. It's a pretty common mistake, but diving right into the willingness to put things down as cast shadows, and to break away from them clinging to the form that casts them, will help push your work forward a great deal.

A quick point about the potato plant. The original demo has a lot of strong cast shadows throughout it, which help give the filled spaces of black a degree of context. Since you didn't include those cast shadows, it just looks like you filled the negative space between the leaves with solid black, something that clashes with how reality generally works. In my demonstration, I'm trying instead to capture the illusion that those spaces are so full of cast shadows (upon the soil itself) - and so the other cast shadows are necessary. In general, you shouldn't be just filling spaces in your drawings with solid black - it should always be reserved, as I mentioned before, for actual cast shadow shapes.

Skipping down to the corpse plant I wanted to point out that the conical form in the center has been drawn only insofar as it is visible. Where the petals around it hide the form, you haven't drawn through them. In general, it is best to draw each and every form in its entirety, so as to better understand how each one sits in 3D space, and how they relate to one another.

Lastly, in regards to your morel mushroom - which is quite a challenging subject - I actually have a full demonstration for how to tackle this sort of thing right here.

All in all your work is coming along well, though you do have a few things to keep in mind. I'll go ahead and mark this lesson as complete.