Coral Cactus Botanical Illustration

I am taking a botanical rendering class and this was our first assignment.
I had originally planned on rendering all 3 of the drawings but my teacher suggested that I make them different
from each other by having the color seep out of the middle and into the plants on either side,
fading back into the tonal rendering.

Materials:
Prismacolor colored pencils (30 colors used in this drawing I think)
Arches Hot Press Watercolor paper 140lb