What is the X in X-mas?
woody vine, in the grape family (Vitaceae), that climbs by means of disk-tipped tendrils. It is commonly found in eastern North America and is often grown as a covering vine for walls, fences, and trunks of large trees. Its fall colour ranges from yellow to red-purple. Several cultivated varieties, with smaller leaves and shorter tendrils, have been developed to provide denser coverage. A related woody vine, Boston ivy, is similarly used.