Thuja occidentalis, also known as northern white-cedar or eastern arborvitae, is an evergreen coniferous tree, in the cypress family Cupressaceae, which is native to eastern Canada and much of the north, central and upper Northeastern United States, but widely cultivated as an ornamental plant. The species was first described by Carl Linnaeus in 1753, and the binomial name remains current.
One of the common names for the Northern White Cedar is arborvitae, meaning 'tree of life' "due to the supposed medicinal properties of the sap, bark, and twigs" (Wikipedia). Despite its name, this tree actually belongs to the cypress family, and the noble quality ascribed to cypress in J.K.'s wand lore also applies to northern white-cedar. As for the color, the wood is white with a golden glow. Slow growing but long-lived, this wood and its owner are methodical in their approach to life. They are in no hurry to prove themselves to anyone and go at their own pace. As such, it excels at the magic that requires complexity in thought as well as consideration of each step of the process, whether it be casting, potion brewing, etc. Spreading oneself too thin is a noted problem among northern white-cedar. Another is to concentrate on a task to the point of being oblivious of what is happening around them, which also means they have strong wills to not leave tasks unfinished.
Healing is a common talent. Cold therapy, cleansing (physically or mentally) or purifying corrupted magic are common healing magic sub-types for northern white-cedar. Potion making comes easy for the owner, as does the cooking (this may be affected by the core, as fire-based cores can indicate a tendency to burn water, so to speak). There is an elemental tendency towards ice-based magic, with almost equal talent for water-based magic. Whether ice or water dominates the magical composition of the wand depends on which type is used more frequently.