The article revises the accomplishments of professor Peter Woldemar Hannikainen, the former director of Forest Service of Finland, in the development of forest sector in the end of 1800s and beginning of 1900s.
The PDF includes a summary in German.
The article describes the adolescence and the birth of his interest in botany of well-known Finnish botanist, professor Johan Petter Norrlin, born in 1842, specialized in Hieracium species.