Ivanova, E.I., N.E. Bell, O.I. Kuznetsova, E.A. Ignatova &
M.S. Ignatov. The
genus Polytrichum sect. Aporotheca (Polytrichaceae)
in Russia
Arctoa (2015) 24: 67-78
doi: 10.15298/arctoa.24.10
Revision of
herbarium collections and analysis of rps4 and
trnL-F molecular sequence data supports the
recognition in Russia of four species of Polytrichum
sect. Aporotheca. Most specimens from the territory of Russia previously
named as P. formosum are transferred to P. densifolium. The species status of the latter is
resurrected and the distinction of P. formosum
and P. densifolium is discussed. The four
species are described based on the material from Russia, their distributions
are summarised, diagnostic characters are
illustrated, and a key to identification is provided.