The study reports on species knowledge among German adolescents (n = 507) as: (1) self-assessed evaluation of one's species knowledge; and (2) factual knowledge about popular local herbs and trees. Besides assessing species knowledge, we were interested in whether selected demographic factors, environmental attitude (as measured through the New Ecological Paradigm) and environmental preferences (measured through the Teen Environmental Preference Questionnaire) may predict species knowledge. Overall, pupils showed better knowledge of trees than of herbs. The Stinging Nettle ("Urtica dioica") was the best known species among a total of 16 presented tree and herb species. Linear regression analyses revealed that female gender influenced knowledge about trees positively, while it showed a negative relation towards self-assessed evaluation of one's species knowledge. In addition, higher age, urban provenance and the environmental preference dimension "city" showed a negative relation with species knowledge of trees and herbs. The environmental preference dimension "nature" was positively related to our adolescents' self-assessed evaluation of one's species knowledge. Our results will be discussed in the light of educational strategies to foster young people's species knowledge.