What are the main differences between...?

Question

pinnate reticulate, parallel and palmate leaf venation?

The examples I keep finding all seem to contradict each other. I was under the impression a midrib vein was absent in a parallel leaf, but I find pictures of "parallel veins" apparently containing a midrib.

Picture links would be especially welcome; thanks!

Answer 1

http://www.uwsp.edu/cnr/leaf/index.htm This site may help. It pays to remember that not all specimens will fit exactly the description given in any key. Nature uses individual variations to keep us from becoming too categorical.