Taxonomic status of Plagiochila semidecurrens var. alaskana and P. semidecurrens var. longifolia (Plagiochilaceae)
2020 年 11 巻 p. 31-39
詳細
2020 年 11 巻 p. 31-39
Plagiochila alaskana A.Evans has been considered as an extreme form of P. semidecurrens (Lehm. & Lindenb.) Lindenb. and also recognized as a variety: P. semidecurrens var. alaskana (A.Evans) Inoue. After studying the holotype of P. alaskana the authors are of the opinion that P. alaskana should be considered as an independent species and not as a variety under P. semidecurrens. Study of the holotype specimen of a further taxon in this group, Plagiochila semidecurrens var. longifolia Inoue reveals leaf length : width ratios ranging from 1.5–2.5 : 1.0 which in turn supports the view of it being a habitat modification of P. semidecurrens. Therefore, we are of the opinion that var. longifolia should be treated as a synonym under P. semidecurrens as proposed by Inoue.
