starts its vegetative period before full foliation of the tree storey. During this time, it is exposed to high solar radiation, which presents a potential danger for the plant. After leaf out, the amount of solar radiation decreases. The plant is adapted to changing conditions with efficient protective and repair mechanisms (morphological characteristics of leaves, epidermal structure, UV-B absorbing substances). After foliation, the amount of photosynthetic pigments in plant leaves slightly increases due to less daylight available. On the contrary, the UV-B absorbing substances (flavonoids and anthocyanins) are significantly reduced after foliation. Gallery References Pignatti S. - Flora d'Italia – Edagricole – 1982, Vol. II, pag. 407 Tutin, T.G. et al. - Flora Europaea, second edition - 1993 External links Biolib Pulmonaria officinalis officinalis Plants described in 1753 Taxa named by Carl Linnaeus