I wondered if maybe my problem with drawing had anything to do with being faced with a blank page. So I crumpled up some tissue paper and glued it onto these two pages then painted over it with gesso and I must admit that once I'd made that mess I didn't feel quite so intimidated.
So I went for it. I used oil pastels (as suggested by Gina ) to draw the cow parsley and I have since gone over it with green ink.

This time I had a go at drawing on a normal page. I have also gone over this one with ink and I think this one looks much better so I won't bother with the tissue paper again.
Here it is, I used the ink at full strength and I think it's too strong.