Cathaya

Cathaya is a genus in the pine family, Pinaceae, with one known living species, Cathaya argyrophylla. Cathaya is a member of the subfamily Laricoideae, most closely related to Pseudotsuga and Larix. A second species, C. nanchuanensis, is now treated as a synonym, as it does not differ from C. argyrophylla in any characters.

Cathaya is confined to a limited area in southern China, in the provinces of Guangxi, Guizhou, Hunan and southeast Sichuan. It is found on steep, narrow mountain slopes at 950–1800 m altitude, on limestone soils. A larger population has been reduced by over-cutting before its scientific discovery and protection in 1950.

The leaves are needle-like, 2.5–5 cm long, have ciliate (hairy) margins when young, and grow around the stems in a spiral pattern. The cones are 3–5 cm long, with about 15–20 scales, each scale bearing two winged seeds.

One or two botanists, unhappy with the idea of a new genus in such a familiar family, tried to shoehorn it into other existing genera, as Pseudotsuga argyrophylla and Tsuga argyrophylla. It is however very distinct from both of these genera, and these combinations are not now used.

The Butchart Gardens in Victoria, British Columbia had a small living specimen. The tree died in 2017.

Whistling Gardens in Wilsonville, Ontario has a young specimen in its plant collection.

Hoyt Arboretum in Portland, Oregon has a specimen in its collection. Hoyt’s tree is propagated from a tree that was probably imported illegally back in the 1990s.

Fossil record
Cathaya sp. fossils are described from the early Pleistocene of southern Portugal. They are abundant in European brown coal deposits dating from between 10 and 30 million years ago.