Spirina, U.N. & M.S.
Ignatov. On the branch development in Fontinalaceae
(Bryophyta)
Arctoa (2011) 20: 119-136
The branch
primordia in Fontinalis, Dichelyma and Brachelyma are studied. The
most common pattern in the family is that the outermost branch leaf is in
‘eleven o’clock position’, due to a reduction of the first branch leaf that
starts to develop in ‘four o’clock position’. Strong elongation of the stem and
an extensive displacement of the branch primodium far from the leaf axil are
probably the main factors of this reduction. However, in some species of Fontinalis
the first branch merophyte produces lamina, either single or compound; at
the same time, in F. hypnoides both the first and second branch leaves
are reduced, so the outermost leaf is in ‘twelve o’clock position’. The branch
‘foot’ formed of the bases of proximal branch leaves is
discussed.