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Vascular Bundles

Butternut “Monkey” Leaf Scars

Butternut (Juglans cinerea), also known as White Walnut,  is a species of walnut native to New England. Butternut has several distinctive characteristics, one of the most memorable being the pattern on the scars that are left when a leaf falls off.  The vessels that transport food from the leaves to the roots and water from the roots to the leaves, phloem and xylem, respectively, are called vascular bundles.  They are darker than the rest of the scar, and are arranged in such a way on Butternut twigs that the leaf scar resembles nothing more than the face of a monkey! A fuzzy “brow” completes the likeness. (Black Walnut (Juglans nigra), a close relative, has leaf scars that also look like monkey faces, but they lack the furrowed brows.)

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