Spirina U.N.1, Ignatov M.S.2 2005. A comparison of early stages of branch development in Brachythecium and Calliergon (Bryophyta) // Arctoa. Vol. 14: 211–222 [in English].
1 Tver State University, Zhelyabova str., 33, Tver 170000 Russia
2 Tsitsin Main Botanical Garden of Russian Academy of Sciences, Botanicheskaya 4, Moscow 127276 Russia
KEYWORDS: plant development, apical cell, anatomy, branch initials, primordial leaf arrangement, leaf reduction, Hypnales, Brachythecium, Calliergon
ABSTRACT. Early stages of branch development in Brachythecium and Calliergon are studied, using serial sections through the shoot apex. Our data suggest that the specific arrangement of pseudoparaphyllia (or, in alternative terminology, proximal branch leaves) of Brachythecium are likely caused by reduction of the two outermost pseudoparaphyllia that are developed in most of other pleurocarpous families, including Calliergon.