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live in forest settings. The National Arboretum is presently engaged in obtaining seed 

 source collections of different hemlock species to evaluate for resistance to this pest 

 (Garvey, personal communication). 



Port-Orford-Cedar Root Disease 



Port-Orford-Cedar (Chamaecypans lawsoniana) is endemic to a limited range along the 

 Pacific Coast from Coos Bay, Oregon to northern California. Port-Orford-Cedar-dom- 

 inated forests are floristically diverse communities and are considered to be uniquely 

 beautiful landscapes by recreational visitors. The species is valuable for its highly aro- 

 matic wood and is commercially widely used as a landscape planL Native Port-Orford- 

 Cedar populations have been decimated by a root disease caused by die exotic fungus 

 Phytophthara lateralis. The disease was first reported in 1923 in a nursery near Seatde 

 (Hunt in Zobel et aL 1985). The origin ot Phytophthara lateralis remains unknown, al- 

 though the partial resistance of Asian Chatnaecypans species has led some to speculate 

 that it is Oriental in origin (Roth et al. 1987). The disease inidally infests fine roots 

 by direcdy penetrating into succulent ussues, and eventually colonizes the enure root 

 system. Mortality occurs in seedlings widiin a few days, while a large u-ee may take sev- 

 eral years to die. The fungus grows only in living tissue and is not found independent- 

 ly in the soil (Ostrofsky et aL 1977). 



Natural range of Port-Orford-ddar 



