Spirina, U.N. & M.S. Ignatov. Bilobed leaves in mosses? Structure and adaptive significance of proximal branch leaves in Lembophyllaceae
Arctoa (2015) 24: 124-140
Branch primordia in the moss family Lembophyllaceae demonstrate an outstanding polymorphism in proximal branch leaf arrangement around young branches. The first and second branch merophytes may not develop leaf lamina at all or form a deeply divided lamina or ‘compound leaf’, where 2–3(–4) individual laminae are somewhat distant one from another. Bilobed leaves occur in all genera of the family, being more common in the genera Weymouthia and Camptochaete. The lobate structure allows proximal leaves to form a slot-like clasps, likely having a protective significance. The early stages of branch development are shown in a series of sections of Weymouthia cochlearifolia.