Thuja is a genus of coniferous trees in the Cupressaceae (cypress family). There are five species in the genus, two native to North America and three native to eastern Asia. The genus is monophyletic and sister to Thujopsis.
They are commonly known as arborvitaes, (from Latin for tree of life) thujas or cedars.
Thuja are an extremely fire prone species, and shoud not be planted in the defensible space zone or near driveways or roadways.
If removal is not an option, specimens should be spaced and maintained free of all dead twigs and needles, with lower limbs removed to provide ground separation.