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 oclock position, due to a reduction of the first branch leaf that starts to develop in four oclock 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 oclock position. The branch foot formed of the bases of proximal branch leaves is discussed.