作 者 ：XIANG Qiao-Ping, FU Li-Kuo
期 刊 ：植物分类学报 1998年 5期
Keywords:Abies, Leaf cuticle, Systematics,
Abstract:
Comparative investigation of the inner surface of the needle cuticle of 36 species
and 2 varieties of Abies under SEM has revealed that the characteristics of the intercellular
flanges are rather distinct and four types can be distinguished: (1) Straight and developed
single flange. This type is only represented by Abies bracteata D. Don. Morphologically,
this species is also quite unique in the genus Abies and was once treated as a subgenus by
Franco and Liu. Its special structure of the leaf cuticle observed here seems to support their
treatment. (2) Double flanges. This type was first discovered in a leaf fossil of Abies from
England. In modern plants of Abies, it is found only in the species from Central America.
(3) Undeveloped single flange. This type is represented by a small group of Abies from the
west and east coastal area of the Pacific Ocean. (4) Undulate and developed single flange.
This type is represented by most of the species of Abies, including all the species in Europe
and most species in Asia and North America. The flange types mentioned above seem to have
some relationships with the geographical distribution of the species in the genus Abies, and
their occurrence might have not been completely influenced by the habitats, hence the fea-
tures of the intercellular flanges may provide good evidence for the subgeneric division of
Abies. Based on our results and those from the previously published literature about the infra-
generic treatments of Abies and the distribution of the fossils, we consider that western
North America might be the diversity center of modern Abies. Florin once pointed out that
the characters of the leaf cuticle in gymnosperms are of great significance for the generic and
infrageneric division. This viewpoint is strongly supported by our study on modern Abies.