Cunninghamia is a genus of one or two living species of large evergreen coniferous trees in the cypress family Cupressaceae, order Cupressales. It is the most basal extant member of Cupressaceae, with a lineage that diverged from the rest of the family during the early Jurassic — making it among the most ancient surviving conifer lineages on Earth.
Trees grow in a distinctive conical form with tiered, horizontal branches that are often pendulous toward the tips, and can reach 70 m (230 ft) in height. The leaves are needle-like, leathery, and softly spined, 2–7 cm long and spirally arranged with an upward arch; they carry two white or greenish-white stomatal bands on the underside. Old needles may persist on stems for up to five years, giving older specimens a characteristic ragged appearance. Bark on mature trunks peels away in strips to expose reddish-brown inner bark, and trees often sucker around the base — particularly after stem or root damage — producing a multi-trunked habit. The seed cones are ovoid to globose, 2.5–4.5 cm long, and mature in 7–8 months; each scale bears 3–5 seeds.
The genus contains two recognised species: Cunninghamia lanceolata (China fir), native to mainland China, Vietnam, and Laos; and Cunninghamia konishii (Taiwan fir), restricted to Taiwan. Molecular evidence suggests the two may be conspecific, with Taiwanese populations derived from multiple colonisations of the mainland, but scientific consensus on their merger is not yet settled. In the past the genus was placed in the family Taxodiaceae, now folded into Cupressaceae; a small number of botanists have proposed a separate family Cunninghamiaceae, but this treatment has not gained wide acceptance.
Though it superficially resembles conifers of cold climates, Cunninghamia is highly heat-tolerant and grows down to sea level in subtropical regions such as Hong Kong. It is commonly known as China-fir, though it is not a true fir (genus Abies).
Etymology
The genus name Cunninghamia honours two figures: Dr. James Cunningham, a British physician who introduced the species into European cultivation in 1702, and botanist Allan Cunningham.
Distribution
Cunninghamia lanceolata is native to mainland China, northern Vietnam, and Laos; Cunninghamia konishii is restricted to Taiwan. The genus may also occur in Cambodia. Both species grow from montane forest down to sea level in subtropical areas.
Taxonomy Notes
Cunninghamia is the sole living genus of the subfamily Cunninghamioideae (Cupressaceae), a lineage whose fossil record extends to the Middle Jurassic and which diversified greatly during the Cretaceous before a severe end-Cretaceous decline. Oldest assigned fossils include Cunninghamia hornbyensis from British Columbia and Cunninghamia taylorii from Alberta (Late Cretaceous, Campanian). Further fossils are known from Cenozoic deposits across Asia, North America, and Europe. Phylogenetically it is the most basal extant member of Cupressaceae. Whether the two living species (C. lanceolata and C. konishii) should be treated as one or two species remains debated; if combined, C. lanceolata has name priority and the Taiwan taxon becomes C. lanceolata var. konishii.
