Whatever type of tree this is, it's really neat with the colors and markings on the trunks and branches. I've never seen this before. The trunks are rather smooth with white and orange and a light overall grayish brown.
Pen and ink only first and then used a white charcoal pencil and watercolor pencils to add just a bit of color. My main goal was to capture the white and orange that grabs my attention.
Last thing I added with pencil only was the fence that stands behind the trees. I feared using pen and ink might take away from the tree trunks making it all look cluttered.
Strathmore Softcover Tan Sketchbook and Sheaffer Calligraphy pen with Italic nib (small).