In Ky. this northeastern tree occurs in the wild mostly on calcareous bluffs of the Cumberland Rv. and its Big South Fork. It has also been widely planted (espcially in cemeteries), and there are many cultivars, some of which often suffer from winter-browning unlike native trees. East Asian relatives classified in the genera Thuja or Platycladus have also been planted but escapes from seed are unknown in Ky. (CW) and generally elsewhere in North America (FNA 2, K, W). These species tend to be much browsed by deer in winter (Fargione et al. 1991, Cornett et al. 2000). Restriction of T. occidentals to steep bluffs across the southern part of its range could have been enhanced by browsing. Foliage and bark of this species has considerable nutritional value during winter for herbivorous mammals (even starving humans), providing essential amino acids and vitamin C (e.g. Durzan 2009). In addition, its rich phenolic chemistry (including terpenoids, lignans, dienoic acids) has considerable medicinal potential despite some strong tastes; the lignans are unusual but similar to those in Podophyllum (e.g. Chang et al. 2000).