Object Drawing 1

I signed up for a free, online course through edX: Natural History Illustration. I must have thought I had some free time. I don’t, but I signed up anyway. Here is my object drawing for the first assignment: cattail, gourd, petrified wood (just in case you can’t tell). I’m not sure what the reference notes are supposed to include for a natural history illustration. Thank goodness for Wikipedia, is all I can say.

Illustration 1