Complex sentence: Over 100 "Pinus sylvestris" varieties have been described in the botanical literature, but only three or four are now accepted; they differ only minimally in morphology, but with more pronounced differences in genetic analysis and resin composition.
Split into simpler sentences: Over 100 "Pinus sylvestris" varieties have been described in the botanical literature, but only three or four are now accepted. They differ only minimally in morphology, but with more pronounced differences in genetic analysis and resin composition.