Abies ferreana Bordères & Gaussen

Bordères-Rey & Gaussen named Abies ferreana in 1947 for the French botanist Yvette de Ferré (1915–2003) who at the time had ‘already published beautiful works on conifers’ (Bordères-Rey & Gaussen 1947). It remains a poorly understood species, reportedly ocurring very locally in scattered stands in the same general area as A. georgei. Prominent among the barriers to better understanding it is the fact that Bordères-Rey & Gaussen only cited a single specimen in their protologue (Yu 12326) (Bordères-Rey & Gaussen 1947). Furthermore, their description appears to mix and match foliar characters from sterile and coning shoots; the latter are known for exhibiting atypical and variable character states, such as resin canal position (see below). Nevertheless, A. ferreana remains the most appropriate name for material distributed in NW Yunnan, SW Sichuan, and perhaps SE Xizang (Tibet), fitting neither A. forrestii nor A. georgei.

Much has been made of the medial position of the resin canals in the leaves of fertile branches of A. ferreana. This is an oft-cited character, but a variable one in many species, and it should probably not be relied upon as absolutely diagnostic (Panetsos 1992; and see genus description for further discussion). Nevertheless, A. ferreana can be distinguished from other closely related species in the following ways: one-year shoots dark reddish-brown (cf. yellowish-grey or yellowish-brown or grey-brown in A. chayuensis); shoots densely pubescent (cf. glabrous in A. forrestii); winter buds pale golden-brown with a translucent resin (cf. covered in a thick, chalky, wax-like resin in A. georgei) (Bordères-Rey & Gaussen 1947). The shape of the apex (exserted part) of the bract scale is emarginate, abruptly tapering to a cusp; in this character A. ferreana is similar to A. forrestii and to some forms of A. georgei, but it differs from these in its smaller seed cones, typically 5–8 cm long (cf. 10–14 cm long) (Farjon 2017; Bordères-Rey & Gaussen 1947; Fu, Li & Mill 1999). The bract cusp of A. ferreana can be elongated and erect, and this could reasonably be assumed to be the inference behind the name var. longibracteata, but the type specimen of that taxon is clearly referable to A. georgei (see that article for discussion).

A. ferreana was introduced to cultivation in the early 20th century by Forrest and later by Kingdon-Ward (Rushforth 1987) but it is doubtful that any old trees remain in collections. Several introductions since 1980 have been tentatively identified as this species, but only KGB 503 and C&H 6158 appear to be genuine. As they mature, it may be that some of the BCHM gatherings of 2011 are identified as this species. In cultivation it seems to prefer the same general conditions as A. forrestii and A. georgei.